Gas-liquid mixed electrochemical reaction device for treating landfill leachate and method for treating landfill leachate using same

Abstract

Disclosed is a gas-liquid mixed electrochemical reaction device for treating landfill leachate. The device comprises an electrolytic cell mainly composed of an electrolytic cell body, an electrolytic anode, an electrolytic cathode, and an electrolytic power source, where the electrolytic anode is connected to a positive electrode of the electrolytic power source, and the electrolytic cathode is connected to a negative electrode of the electrolytic power source. The device is characterized in that: the electrolytic cell further comprises at least one electrolytic cell gas-liquid mixer and an electrocatalytic component to form a gas-liquid mixed electrolytic cell; an outlet of the electrolytic cell gas-liquid mixer faces the electrolytic cell body or is located therein, and is used to bring a gas-liquid mixture, obtained by mixing an electrolyte inside the electrolytic cell with a reaction gas, into contact with the electrocatalytic component. Further disclosed is a method for treating landfill leachate using the device.

Description

A gas-liquid mixed electrochemical reaction device for treating landfill leachate and a method for treating landfill leachate Technical Field

[0001] The invention belongs to the technical field of waste liquid treatment, and in particular relates to a gas-liquid mixed electrochemical reaction device for treating landfill leachate and a method for treating the landfill leachate. Background Art

[0002] With socioeconomic development and the continuous improvement of people's living standards, the amount of domestic sewage and organic wastewater from factories has increased, polluting water sources. This is particularly true in landfills, where black or yellowish-brown leachate with a foul odor is generated and discharged during the garbage storage process. This wastewater, in addition to containing numerous pathogens, also contains various difficult-to-degrade organic matter, heavy metals such as chromium, lead, and copper ions, suspended solids, phosphorus and nitrogen pollutants, and microplastics. It is a typical organic wastewater characterized by high discharge volume, complex composition, water quality fluctuations, and high biological toxicity.

[0003] The total nitrogen concentration in landfill leachate typically ranges from 2000mg / L to 3500mg / L, with some levels exceeding 4000mg / L. Nitrogen pollutants are categorized by molecular structure as ammonia nitrogen, organic amines, and nitrate nitrogen. Ammonia nitrogen (NH3) accounts for 70-90% of the nitrogen pollutants in landfill leachate. Removing high concentrations of total nitrogen from landfill leachate is a significant challenge in leachate treatment. China's Municipal Waste Landfill Pollution Control Standard (GB16889-2008) requires an effluent total nitrogen level of ≤40mg / L, translating to a 99% total nitrogen removal rate for leachate.

[0004] Currently, biological denitrification is commonly used to treat landfill leachate. However, biological denitrification processes have disadvantages such as long treatment times, high capital and operating costs, large land occupation, long biological culture cycles, significant temperature influences, and high sludge production. Furthermore, because single-stage biological denitrification processes are difficult to meet such high total nitrogen removal rate requirements, a two-stage biological denitrification treatment process must be used to control the total nitrogen in the effluent.

[0005] The existing technology for rapidly treating landfill leachate uses reverse osmosis. After treatment, the clear liquid separated from the leachate can be discharged according to standards, while the concentrated organic waste liquid is either re-injected into the landfill or mixed with combustible gases in a combustion furnace for high-temperature combustion. However, membrane filtration equipment requires significant investment, and current membrane treatment processes offer incomplete results. The cost of incinerating concentrated organic waste liquid is prohibitive. Therefore, a new process technology solution that is easy to develop, requires minimal investment, and provides high efficiency and complete leachate treatment is urgently needed to address this problem.

[0006] Summary of the Invention

[0007] The first object of the present invention is to provide a gas-liquid mixing electrochemical reaction device for treating landfill leachate. The device uses a combination of an electrolytic cell gas-liquid mixer and an electrocatalytic component to improve the gas solubility and mass transfer properties of the reactants, and utilizes electrocatalysis to efficiently treat nitrogen pollutants in the landfill leachate, thereby economically and quickly bringing the total nitrogen in the effluent to emission standards.

[0008] The second purpose is to provide a method for treating landfill leachate using the gas-liquid hybrid electrochemical reaction device, which can use hydrogen to carry out chemical and physical reaction methods under normal pressure to efficiently treat nitrogen pollutants in the landfill leachate, so that difficult-to-treat nitrogen pollutants in the landfill leachate can be efficiently reacted and removed, thereby economically and quickly solving the pollution problem of the landfill leachate.

[0009] The first object of the present invention is achieved through the following technical solutions.

[0010] A gas-liquid mixing electrochemical reaction device for treating landfill leachate comprises an electrolytic cell mainly composed of an electrolytic cell body, an electrolytic anode, an electrolytic cathode, and an electrolytic power supply, wherein the electrolytic anode is connected to the positive electrode of the electrolytic power supply, and the electrolytic cathode is connected to the negative electrode of the electrolytic power supply. The electrolytic cell is characterized in that: the electrolytic cell further comprises at least one electrolytic cell gas-liquid mixer and an electrocatalytic component, forming a gas-liquid mixing electrolytic cell; the outlet of the electrolytic cell gas-liquid mixer is oriented toward or located in the electrolytic cell body, and is used to bring the gas-liquid mixture obtained by mixing the electrolyte in the electrolytic cell with the reaction gas into contact with the electrocatalytic component; the electrocatalytic component adopts any one or more of the following methods:

[0011] Electrocatalytic method (1): at least one electrocatalytic component is arranged in the electrolytic cell body, and the outlet of the electrolytic cell gas-liquid mixer is directed toward the electrocatalytic component and / or the electrolytic anode and / or the electrolytic cathode;

[0012] Electrocatalytic method (2): The electrolytic anode and / or the electrolytic cathode are improved in electrocatalytic performance structure, at least one of the electrolytic anode and the electrolytic cathode is two or more parallel-connected electrodes, and the outlet of the electrolytic tank gas-liquid mixer faces the electrolytic anode and / or the electrolytic cathode with improved electrocatalytic performance structure;

[0013] Electrocatalytic method (3): The electrocatalytic performance structure of the electrolytic anode and / or the electrolytic cathode is improved, and the angle formed by a part or the whole of at least one of the electrolytic anode and the electrolytic cathode and the gas-liquid mixture ejection straight line of the electrolytic tank gas-liquid mixer is greater than 0° and less than or equal to 90°, and the outlet of the electrolytic tank gas-liquid mixer is oriented toward the electrolytic anode and / or the electrolytic cathode with the improved electrocatalytic performance structure.

[0014] The electrolytic cell gas-liquid mixer described in the present invention has an inlet and at least two outlets, or has a structure with a liquid inlet, an air inlet and an outlet. When the electrolytic cell gas-liquid mixer has an inlet and at least two outlets, the outlet extends into the electrolytic cell body and is used to dispersely input the reaction gas or gas-liquid mixture into the electrolyte in the electrolytic cell for gas-liquid mixing; when the electrolytic cell gas-liquid mixer has a liquid inlet, an air inlet and an outlet, the liquid inlet is connected to the electrolytic cell body by a pipeline, and the outlet is directed toward or extends into the electrolytic cell body, and is used to input the electrolyte in the electrolytic cell into the gas-liquid mixer so that it is mixed with the reaction gas entering the gas-liquid mixer and then returned to the electrolytic cell.

[0015] The electrocatalytic components in the electrocatalytic method (1) of the present invention are arranged in the electrolytic cell body and can be located below the electrolyte liquid level, and are used to achieve electrochemical catalytic reaction under the action of electric field force. Specifically, the electrocatalytic components are bipolar electrodes and / or insoluble conductors, and the specific number and location of the electrocatalytic components can be determined according to the performance of the process setting.

[0016] The bipolar electrode described in the present invention refers to an insoluble conductor positioned between the electrolysis anode and cathode, not connected to an external power source, and immersed in the electrolyte. Its shape and size are not limited. During electrolysis, the bipolar electrode, when placed in an electric field, can undergo an electrochemical reaction with the substances located therein, without requiring direct electrical connection to the electrolysis power source. The end closest to the anode acts as a cathode, causing a reduction reaction on some reducible substances in the electrolyte, while the end closest to the cathode acts as an anode, causing an oxidation reaction on some oxidizable substances in the electrolyte. When multiple bipolar electrodes are used, each is ideally an independent conductor with no electrical connection to each other. Under the influence of the electric field, each bipolar electrode can independently function, forming multiple inductive small cathodes and anodes to enhance the electrocatalytic effect. Preferably, a powdered conductor capable of flowing with the electrolyte is used as the bipolar electrode.

[0017] Preferably, as shown in FIG13 , when more than one bipolar electrode is used, the conductive middle surface portion of the bipolar electrode is partially wrapped with insulating material to reduce the risk of the bipolar electrodes becoming one large bipolar electrode due to conduction when in contact with each other, thereby reducing the risk of each small bipolar electrode losing its ability to independently perform its electrode catalytic function.

[0018] The insoluble conductor described herein is directly conductively connected to an electrolytic anode or cathode, transforming the anode or cathode into an irregularly shaped electrode. This increases the electrode surface area and promotes the electrochemical reaction between the electrode and the electrolyte, thereby achieving electrocatalysis. The insoluble conductor connected to the electrolytic anode is referred to as an insoluble anode conductor, while the insoluble conductor connected to the electrolytic cathode is referred to as an insoluble cathode conductor.

[0019] The present invention utilizes the characteristics of an insoluble conductor to mix the reactant gas introduced by the electrolytic cell gas-liquid mixer with the electrolyte to achieve a highly efficient electrocatalytic electrochemical reaction. As shown in Figure 14 , the insoluble conductor 62 is insoluble or poorly soluble in the electrolyte it contacts, and its shape and size are not limited.

[0020] The gas that enters the gas-liquid mixer of the electrolytic cell to participate in the reaction described in the present invention can be divided into oxidizing gas and reducing gas. The oxidizing gas that can participate in the reaction can be at least one of ozone, oxygen, and chlorine; the reducing gas that can participate in the reaction can be hydrogen. The above-mentioned gases participating in the reaction can be self-electrolysis gas and external input gas. The self-electrolysis gas and the electrolyte it mixes with come from the same cell area of ​​the same electrolytic cell, see the embodiments shown in Figures 1, 2, 8, and 11; the external input gas and the electrolyte it mixes with come from different cell areas of the same electrolytic cell, or from outside the electrolytic cell, see the embodiments shown in Figures 4, 5, 6, 7, 9, and 10.

[0021] The working principle of the present invention is to use the electrolytic cell gas-liquid mixer to mix the gas involved in the reaction into the electrolyte, namely the landfill leachate, and then contact the resulting gas-liquid mixture with at least one of the electrocatalytic components, electrolytic anode, and electrolytic cathode in the gas-liquid hybrid electrolytic cell. The gas-liquid mixture containing the oxidizing gas is allowed to contact and react with the negatively charged components of the gas-liquid hybrid electrolytic cell, and / or the gas-liquid mixture containing the reducing gas is allowed to contact and react with the positively charged components of the gas-liquid hybrid electrolytic cell. The presence of sufficient gas in the gas-liquid mixture promotes an electrochemical reaction in the components with one charge, and the resulting electron gain and loss catalyzes a positive electrochemical reaction in the components with the other charge, while preventing the substances in the electrolyte to be treated from being repeatedly reacted in the components with both charges and causing consumption. Compared with liquid oxidants or reducing agents, the use of oxidizing or reducing gases can better produce catalytic effects on electrochemical reactions, is less expensive, and does not increase the amount of electrolyte. In the gas-liquid hybrid electrolytic cell, when electrolysis is carried out, the negatively charged component is at least one of the electrolysis cathode, one end of the bipolar electrode that functions as the cathode, and an insoluble conductor that is directly and electrically connected to the electrolysis cathode; and the positively charged component is at least one of the electrolysis anode, one end of the bipolar electrode that functions as the anode, and an insoluble conductor that is directly and electrically connected to the electrolysis anode. That is, to achieve an electrocatalytic effect, during the electrolysis process, the present invention uses an oxidizing gas to conduct an electrochemical reaction in the negatively charged component to seal the component, thereby ensuring that the reducing substance to be treated can be electrochemically oxidized in the positively charged component without being reduced by the negatively charged component; or uses a reducing gas to conduct an electrochemical reaction in the positively charged component to seal the component, thereby ensuring that the reducing substance to be treated can be electrochemically reduced in the negatively charged component without being oxidized by the negatively charged component. During the electrolysis process, the positively charged components convert electrical energy into chemical energy, electrocatalytically oxidizing reducible substances in the electrolyte. They also oxidize oxygen, hydroxide ions, chloride ions, and other radicals in the electrolyte to produce large quantities of superoxide radicals (O2·), hydroxyl radicals (OH·), and / or chlorine radicals (Cl·), chloroxyl radicals (ClO·), and other oxidizing free radicals, rapidly oxidizing substances in the electrolyte that require oxidation treatment, such as oxidizable organic matter and inorganic ammonia in landfill leachate. Furthermore, the negatively charged components convert electrical energy into chemical energy, electrocatalytically reducing oxidizable substances in the electrolyte. They also generate large quantities of hydrogen radicals (H·) or protons, which rapidly react with substances in the electrolyte that require reduction treatment, such as reducible organic matter and nitrogen oxides in landfill leachate, to undergo at least one of hydrogenolysis, hydrogenation, and reduction reactions.

[0022] When a gas-liquid mixture containing an oxidizing gas is sprayed onto a negatively charged component in the electrolysis process, taking sufficient oxygen as an example, the main electrochemical reaction occurring at the negatively charged component is: O2+4H + +4e - →H2O.

[0023] When a gas-liquid mixture containing reducing gas is sprayed onto a positively charged component in the electrolysis process, taking sufficient hydrogen as an example, when the electrolyte contains organic matter, in addition to the organic matter reduction reaction, the main electrochemical reaction occurring at the positively charged component is: H2-2e - →2H + , or H2+2[OH] - -2e - →2H2O.

[0024] The electrolytic cell of the present invention can be further provided with a cell divider according to the process design to divide the cell into at least two cell zones. The purpose of providing the cell divider within the electrolytic cell is to prevent bubbles generated by electrode electrolysis in one cell zone from crossing over to other cell zones and causing adverse reactions, or to prevent at least some ions and molecules in the electrolyte in one cell zone from migrating to other cell zones under the action of the electric field, or to effectively isolate the cathode and anode electrocatalytic components disposed on either side of the cell divider and prevent contact between the cathode and cathode electrocatalytic components, thereby ensuring that the electrolytic cell meets the process requirements.

[0025] Preferably, the electrolytic cell separator divides the electrolytic cell body into an electrolytic cell comprising an anode cell area and a cathode cell area, or divides the electrolytic cell body into a triple cell area electrolytic cell comprising an anode cell area, an intermediate cell area and a cathode cell area.

[0026] When at least two electrolytes with different components and / or concentrations need to exist in the electrolytic cell at the same time during the electrolysis process, at least one layer of electrolytic cell separator 1 is added to the electrolytic cell. # As a partition to effectively block the separation of electrons and water molecules. # It is at least one selected from bipolar membrane, reverse osmosis membrane, cation exchange membrane, anion exchange membrane, and the specific embodiment is shown in Figure 1, Figure 2, Figure 3, Figure 5, and Figure 6. The electrolytic cell separator 1 # In the case of a reverse osmosis membrane, it is preferred to maintain the pH value of the electrolyte within the range of 0.05 to 14 to fully exert the performance of the membrane and extend its service life.

[0027] When only one electrolyte is required in the electrolytic cell during the electrolysis process, no electrolytic cell separator is required in the electrolytic cell, see the electrolytic cell in FIG7 and the electrolytic cell 1 on the left in FIG19-2 , or at least one electrolytic cell separator 2 is added. #The separators are used to allow ions and water molecules to pass through and to ensure that the electrolytic anode, electrolytic cathode and electrocatalytic components are independently separated. In order to effectively avoid electrical short circuits of the electrodes, it is preferred to use an electrolytic cell structure without separators.

[0028] The electrolytic cell separator 2 # The separator is selected from at least one of a non-ion-selective diaphragm, a filter cloth, a filter screen, and an insulating through-hole support baffle. The non-ion-selective diaphragm has micropores that allow ions or molecules to pass through. A specific embodiment is shown in Figure 4 . The electrolytic cell separator shown in the figure utilizes an insulating through-hole support baffle with through holes made of an electrically insulating material. This insulating through-hole support baffle is a non-ion-selective diaphragm and can be designed in any shape according to process requirements.

[0029] Therefore, the gas inlet of the electrolytic cell gas-liquid mixer is connected to the electrolytic cell area connected to it in liquid flow, and / or the gas inlet is connected to an external gas source. The external gas source is a gas source outside the electrolytic cell area connected to the electrolytic cell gas-liquid mixer in liquid flow, including a gas source outside the electrolytic cell area not connected in liquid flow within the same electrolytic cell and a gas source outside the electrolytic cell. Depending on the source of the gas participating in the reaction in the electrolytic cell, the gas-liquid mixing electrochemical reaction device is divided into the following three types.

[0030] (1) Type A tank: The electrolytic tank gas-liquid mixer uses self-electrolyzed gas as the gas source for the reaction. As shown in Figures 1 and 2, the gas inlet of the electrolytic tank gas-liquid mixer is connected to the top of the electrolytic tank area where its outlet is located. The gas electrolyzed by the electrolytic electrode in the tank area is mixed with the electrolyte in the tank area by the electrolytic tank gas-liquid mixer to form a gas-liquid mixture, which then contacts the electrolytic electrode and / or electrocatalytic component in the tank area to perform an electrochemical reaction. The type A tank shown in Figure 1 is provided with an electrolytic tank partition 1 # The electrocatalytic component placed in the tank area where the electrocatalytic reaction is carried out in the electrolytic cell of 2 adopts a bipolar electrode; the A-type tank shown in Figure 2 is divided into two electrolytic cell areas, the cathode and the anode, by the electrolytic cell separator 2, and electrocatalytic components are placed in both areas, and both use bipolar electrodes and insoluble electrodes.

[0031] (2) Type B cell: The electrolytic cell gas-liquid mixer uses both self-electrolyzed gas and external input gas as gas sources for the reaction. As shown in Figure 3, the gas inlet of the electrolytic cell gas-liquid mixer is connected to the top of the electrolytic cell tank area where its outlet is located, i.e., the anode tank area. It is also connected to the gas source outside the electrolytic cell. The gas electrolyzed by the electrolytic anode in this tank area combines with the gas from the outside and mixes with the electrolyte in this tank area, and then contacts the electrolytic electrodes and / or electrocatalytic components in this tank area to undergo an electrochemical reaction.

[0032] (3) C-type cell: The electrolytic cell gas-liquid mixer uses external input gas as the gas source for the reaction. As shown in Figures 4 to 7, the gas inlet of the electrolytic cell gas-liquid mixer is connected to a cell area in the same electrolytic cell that is not connected to the liquid flow and / or a gas source outside the electrolytic cell. The electrolytic cell gas-liquid mixer mixes the gas from outside the cell area with the electrolyte in the cell area to form a gas-liquid mixture, which contacts the electrolytic electrodes and / or electrocatalytic components of the cell area to undergo an electrochemical reaction.

[0033] The C-type tank can be further divided into C-1 type tank and C-2 type tank according to the source of the external input gas used.

[0034] The external input gas used by the C-1 type cell and the electrolyte it is mixed with come from different cell areas of the same electrolytic cell, that is, the air inlet of the electrolytic cell gas-liquid mixer is connected to a cell area in the same electrolytic cell that is not connected to the liquid flow, see the embodiments shown in Figures 5 and 6; the external input gas used by the C-2 type cell comes from the outside of the electrolytic cell, that is, the air inlet of the electrolytic cell gas-liquid mixer is connected to a gas source outside the electrolytic cell, see the embodiments shown in Figures 3, 4, 7, 9, and 10.

[0035] The C-type cell of the present invention can select an electrolysis power source to apply a voltage value between the electrolysis anode and the electrolysis cathode that is higher than the decomposition voltage value of the electrolyte to perform an operation in the electrolysis process to obtain external input gas from different cell areas of the same electrolytic cell. Alternatively, the electrolysis power source can select an electrolysis power source to apply a voltage value between the electrolysis anode and the electrolysis cathode that is less than or equal to the decomposition voltage value to perform an electrolysis operation to use only external input gas from outside the electrolytic cell and avoid gas electrolysis from the electrolysis electrodes in the electrolytic cell.

[0036] The electrolyte decomposition voltage described in the present invention refers to the critical value at which the voltage applied by the electrolysis power supply between the electrolysis anode and the electrolysis cathode in a static state of the electrolytic cell electrolyte just causes the electrolyte to electrolyze a trace amount of oxidizing gas or a trace amount of reducing gas. The electrolyte decomposition voltage is related to a variety of factors, including the electrolyte concentration, viscosity, temperature, the amount of gas involved in the reaction, the distance between the cathode and cathode, and the materials used for the cathode and cathode. Therefore, in the C-1 type cell, to achieve electrolytic gas deposition at the anode and / or cathode, the voltage applied by the electrolysis power supply between the anode and cathode during operation must be higher than the electrolyte decomposition voltage. Specifically, the electrolysis cell structure shown in Figures 5 and 6 can be used. In the C-2 type cell, to prevent electrolytic gas deposition at the anode and / or cathode, the voltage applied by the electrolysis power supply between the anode and cathode during operation must be less than or equal to the electrolyte decomposition voltage. Specifically, the electrolysis cell structure shown in Figures 4 and 7 can be used.

[0037] But when having sufficient reducing gases to participate in the electrochemical reaction of electrolysis anode and / or bipolar electrode anode end and make electrolysis anode and bipolar electrode anode end be difficult to electrolysis oxidizing gas, or when having sufficient oxidizing gases to participate in the electrochemical reaction of electrolysis cathode and / or bipolar electrode cathode end and make electrolysis cathode and bipolar electrode cathode end be difficult to electrolysis reducing gas, the electrolysis power supply of described C-2 type groove applies the voltage value between electrolysis anode and the electrolysis cathode and can be slightly higher than the electrolyte decomposition voltage value.When being regulated higher because of the electrolysis power supply applying the voltage value between electrolysis anode and the electrolysis cathode, under these conditions, the reducibility of its electrolysis cathode or the oxidizability of its electrolysis anode can become stronger more.So now, adopt C-2 type groove, under safe situation, electrolysis power supply can be set to apply the voltage value between electrolysis anode and the electrolysis cathode and be slightly higher than the electrolyte decomposition voltage value, to improve electrochemical reaction speed.

[0038] The electrolytic cell body of the present invention is made of a polymer resin at the contact portion with the electrolyte, or other materials and coated with an insulating anti-corrosion coating or lined with an insulating anti-corrosion material at the contact portion with the electrolyte. Preferably, when the reaction solution temperature is high, the electrolytic cell body is made of polytetrafluoroethylene.

[0039] The surface of the electrolytic anode is selected from at least one material selected from the group consisting of gold, platinum, nickel, alloys containing at least one of the aforementioned metals, titanium-coated insoluble anodes, and graphite, and its shape and size are not limited. The surface of the electrolytic cathode is selected from at least one material selected from the group consisting of gold, platinum, silver, titanium, copper, nickel, alloys containing at least one of the aforementioned metals, stainless steel, and graphite, and its shape and size are not limited. The electrolytic power supply is a suitable electrolytic power supply that can meet the operating voltage and current density requirements of the gas-liquid hybrid electrochemical reaction device during the electrolysis process.

[0040] When the electrocatalytic component described in the present invention utilizes a bipolar electrode, its material can be a metal, metal oxide, semiconductor, or other conductive material that is insoluble or poorly soluble in the electrolyte it contacts. The appropriate bipolar electrode material is selected based on the conductive material's performance in actual chemical reactions. Preferably, the surface of the bipolar electrode is made of at least one of the following: gold, platinum, nickel, copper, cobalt, iron, nickel, molybdenum, tin, bismuth, aluminum, ruthenium, titanium, tantalum, an alloy containing at least one of the above metals, copper oxide, zinc oxide, aluminum oxide, an insoluble electrode with a titanium-based coating, graphite, or activated carbon. More preferably, the surface of the bipolar electrode used in acidic electrolytes is made of at least one of the following: gold, platinum, graphite, or activated carbon. When using a powdered or granular conductive material that can flow with the electrolyte as the bipolar electrode, a liquid spray pipe is installed to prevent the powdered or granular bipolar electrode from sinking to the bottom or corners of the tank.

[0041] When the electrocatalytic component described in the present invention uses an insoluble conductor, its material can be a conductive metal, a conductive metal oxide, a semiconductor or other conductive material. The appropriate insoluble conductor material is selected based on the performance of the conductor in the actual chemical reaction. Preferably, the material of the insoluble anode conductor is consistent with the material of the electrolytic anode. When the insoluble conductor is in contact with the electrolytic anode, its surface is a material selected from at least one of gold, platinum, nickel, an alloy containing at least one of the above metals, a titanium-based coated insoluble electrode, and graphite. More preferably, when the anode electrolyte is alkaline, the surface of the insoluble conductor arranged in the anode tank area is made of nickel. When the insoluble conductor is in contact with the electrolytic cathode, its surface is a material selected from at least one of gold, platinum, silver, titanium, copper, nickel, an alloy containing at least one of the above metals, stainless steel, and graphite.

[0042] The gas-liquid mixture outlet of the electrolytic tank gas-liquid mixer of the present invention can be designed with the number of nozzles and the shape of the liquid spray according to the spraying object, so that the gas-liquid mixture ejected can effectively and fully contact at least one of the electrocatalytic component, the electrolytic anode, and the electrolytic cathode to achieve better catalytic effect. The electrolytic tank gas-liquid mixer can adopt a bubbling gas-liquid mixer and / or a vacuum jet gas-liquid mixer. From the perspective of safe production and gas-liquid mixing effect, it is preferred to adopt a vacuum jet electrolytic tank gas-liquid mixer, or an electrolytic tank gas-liquid mixer combining a bubbling type and a vacuum jet type (as shown in the number 7-3 in Figure 18). The material of the surface of the electrolytic tank gas-liquid mixer is selected from at least one of titanium, gold, platinum, nickel, conductive graphite, stainless steel, fiberglass, and polymer resin materials, and is specifically selected according to the chemical properties of the electrolyte and the gas participating in the reaction.

[0043] The present invention can also be improved as follows: the electrolytic cell gas-liquid mixer is made of a conductive material and is electrically connected to at least one of the electrolysis power source, the electrolysis anode or the electrolysis cathode, and the connecting conductive wire between the electrolysis power source and the electrolysis anode or the electrolysis cathode. Its outlet is directly inserted into the electrolyte, making it an insoluble anode conductor or an insoluble cathode conductor, which serves as an electrocatalytic component to improve catalytic efficiency. For a specific embodiment, see Figure 7.

[0044] The present invention can also be improved as follows: an air intake branch pipe is added to the air intake pipe of the gas-liquid mixer of the electrolytic cell to introduce multiple or various gases to mix with the electrolyte and then spray them onto the electrolytic anode and / or electrolytic cathode and / or catalytic component to participate in the electrochemical reaction. For a specific embodiment, see the reference numeral 72 in Figure 5.

[0045] The present invention can also be further improved by adding a sealed tank cover with a gas outlet to at least one tank area in a gas-liquid mixing electrolytic cell, thereby providing a perforated seal for that tank area. The gas outlet of the sealed tank cover is connected to or vented to the gas inlet of at least one electrolytic cell gas-liquid mixer and / or other conventional gas-liquid mixer. Gas within the sealed tank area is directed through the gas outlet conduit of the sealed tank cover to the electrolytic cell gas-liquid mixer and / or other exhaust gas treatment device and / or a device for gas recycling, or is discharged through the cover outlet. A specific embodiment is shown as 121 in the accompanying drawings.

[0046] The present invention can also be improved as follows: when the electrolytic cell separator 1 # When an anion exchange membrane or a cation exchange membrane is used to separate the electrolytic cell, a reverse osmosis membrane can be added to the electrolytic cell body to separate an intermediate tank area between the anion exchange membrane or the cation exchange membrane and the reverse osmosis membrane in the electrolytic cell body, and an electrocatalytic component of a bipolar electrode is set in the intermediate tank area; specific embodiments are shown in Figures 5 and 6. Figure 5 shows that two electrolytic cell separators 21 and 22 are set in the electrolytic cell body, where 21 is an anion exchange membrane and 22 is a reverse osmosis membrane, forming an intermediate tank area between the two, where the electrolyte / reactant solution generates a large amount of [OH] - The electrochemical reaction of ions migrating from the electrolytic cathode to the electrolytic anode. In this process, the bipolar electrode plays an electrocatalytic role, which can significantly increase the speed of the oxidation reaction. The electrolytic cell shown in Figure 6 is equipped with two electrolytic cell separators, a reverse osmosis membrane numbered 21 and a cation exchange membrane numbered 22. The electrolyte in the intermediate tank formed between the two generates a large amount of hydrogen ions H + The electrochemical reaction migrates from the electrolytic anode to the electrolytic cathode. In this process, the bipolar electrode will play an electrocatalytic role, which can significantly increase the speed of the reduction reaction.

[0047] The present invention can also be further improved as follows: an adjustable constant voltage electrolysis power supply is used as the electrolysis power supply of the C-2 type cell to ensure a stable output voltage to meet production safety requirements.

[0048] The present invention can further be improved by adopting a symmetrical three-divided tank structure to improve the electrical efficiency of the gas-liquid mixed electrochemical reaction device. Specific embodiments are shown in Figures 8 and 9, wherein:

[0049] Figure 8 is a three-partitioned tank formed by symmetrically arranging the anode tank area with the cathode tank area as the center of the A-type tank shown in Figure 1, wherein the electrolyte in the two symmetrical anode tank areas can be set to two different electrolytes according to the process, or can be set to the same electrolyte.

[0050] FIG9 shows a C-2 type cell of FIG4 , in which the anode cell area is symmetrically combined with the cathode cell area as the center to form a three-part cell, and the electrolyte in the three-part cell is the same electrolyte.

[0051] The present invention can also be improved as follows: the gas-liquid hybrid electrochemical reaction device adopts a circular electrode distribution structure to improve the electrical efficiency of the electrochemical reaction. Specifically, the gas-liquid hybrid electrochemical reaction device adopts a circular or polygonal electrolytic cell, with the electrolysis anode or electrolysis cathode positioned at the center of the cell as a central electrode, and one or more corresponding electrodes of another type positioned around the central electrode.

[0052] The A-type cell shown in FIG11 is one embodiment of the above-mentioned circular electrode distribution structure, wherein the peripheral electrodes outside the center of the electrolytic cell body share the same electrolyte.

[0053] The C-shaped cell shown in Figure 10 is a second embodiment of the aforementioned circular electrode distribution structure. The anolyte and catholyte are the same electrolyte, and the peripheral electrodes outside the center of the cell are separated by insulating partitions and connected to their own electrolysis power sources, forming a combination of multiple independent electrolytic cells within a shared central electrode and electrolyte. Each electrolysis unit includes an electrolysis power source, an electrolysis anode, an electrolysis cathode, an electrocatalytic component, and / or at least one electrolysis electrode with improved electrocatalytic performance.

[0054] The present invention can also be improved as follows: an electrolyte ion current interrupter is added to the line connecting the liquid inlet of the electrolytic cell gas-liquid mixer and the electrolytic cell liquid flow pipeline to cut off the path of the ion flow in the electrolyte that does not flow through the electrolytic anode and electrolytic cathode during electrolysis operation, thereby avoiding the formation of a closed loop circuit with the electrolytic power supply and the loss of useless work. There are two methods for installing the electrolyte ion current interrupter:

[0055] The first type is as shown by number 89 in Figure 11, in which a tank equipped with a multi-hole drip-type baffle or a pipe with an increased cross-sectional area equipped with a multi-hole drip-type baffle is used as an electrolyte ion current cutoff device, and the continuous flow of electrolyte in the pipe is changed to a drip flow mode, so as to cut off the path of ion flow and current in the electrolyte.

[0056] The second type is the electrolyte ion current interrupter 89 as shown in Figure 10, which uses at least two current interruption temporary storage tanks as the electrolyte ion current interrupter, and the two current interruption temporary storage tanks are operated in turn to rotate the ion flow in the electrolyte for interruption, and a liquid level meter is installed in each electrolyte current interruption temporary storage tank to control the pump used by each current interruption temporary storage tank, so that each current interruption temporary storage tank rotates to pump the electrolyte in the tank into the electrolytic tank gas-liquid mixer for chemical reaction; the current interruption temporary storage tank that rotates to pump the electrolyte in the tank into the electrolytic tank does not receive the solution overflowed from the electrolytic tank, and the overflowed liquid of the electrolytic tank is drained to another current interruption temporary storage tank for temporary storage, and the electrolyte is pumped into the gas-liquid mixing electrochemical reaction device in rotation by the two or more tanks to realize the short-circuit channel for cutting off the ion flow.

[0057] The present invention can also be improved as follows: To prevent the electrolysis current from being concentrated at a single point and damaging the electrolytic cell partition, a bipolar electrode with a slotted metal mesh can be installed in the electrolytic cell to evenly distribute the total current passing through the partition, thereby improving the process performance problem of electrolyte resistance variation caused by different bubble densities in the electrolyte. Preferably, the bipolar electrode with a slotted metal mesh is installed between the electrolysis anode and the electrolysis cathode, and close to the electrolytic cell partition. This structural improvement can evenly disperse the electrolysis current through the partition, preventing the electrolysis current from being concentrated at a single point and damaging the electrolytic cell partition. The material selection range of the bipolar electrode with a slotted metal mesh is consistent with that of conventional bipolar electrodes, and the outer dimensions of the mesh frame are set according to the dimensions of the electrolytic cell installation cross-section.

[0058] The present invention can also be improved as follows: a flow deflector for the reaction liquid containing bubbles is added, and the direction and position of the liquid suction port are determined according to the design process of the gas-liquid mixing electrochemical reaction device. Preferably, the flow deflector for the reaction liquid containing bubbles is installed on the side of the electrolysis cathode away from and facing away from the electrolysis anode to guide the electrolyte containing bubbles near the electrolysis cathode, or is installed on the side of the electrolysis anode away from and facing away from the electrolysis cathode to guide the electrolyte containing bubbles near the electrolysis anode; see the number 93 in Figure 6. The main functions of the flow deflector for the reaction liquid containing bubbles include collecting the reaction gas in the electrolyte that does not participate in the electrochemical reaction and re-guiding it together with the electrolyte back to the gas-liquid mixer of the electrolytic tank for gas-liquid mixing again for electrochemical reaction utilization, and keeping the bubbles in the collected liquid absorbed during operation away from the main electric field area to reduce the influence of the bubbles on the uniform distribution of the electrolysis electric field lines. Furthermore, the bubble-containing reaction liquid flow guide cover is connected to a gas-liquid separation washing tank, the gas outlet of the gas-liquid separation washing tank is connected to the gas inlet of the electrolytic tank gas-liquid mixer, and the liquid outlet of the gas-liquid separation washing tank is connected to the electrolytic tank.

[0059] The present invention can also be further improved as follows: the electrode used in conjunction with the bubble-containing reaction liquid flow guide is an insoluble electrode with a through-hole grid structure. The through-holes in the electrode are used to absorb the electrolytic bubbles produced on the electrode and drain the bubble-containing solution into a gas-liquid separation washing tank, so that the electrolytic gas is separated and used from the gas-liquid separation washing tank, and the solution is circulated back to the extraction tank area. The adoption of this improved structural measure can reduce the impact of the electrolytic gas on the uniform distribution of the electric field lines in the electrolytic cell. Specifically, see Figure 6, which shows an embodiment of an electrolytic cathode 4 with a through-hole electrode, which is an insoluble electrode with a through-hole grid structure.

[0060] The present invention can also be improved as follows: the gas-liquid mixing electrochemical reaction device adopts a vertical structure. Since the present invention adopts gas-liquid mixing to carry out electrocatalytic reaction, the gas moves vertically upward in the reaction liquid, so increasing the vertical reaction chamber helps to improve the reaction efficiency. Preferably, the outlet of the electrolytic tank gas-liquid mixer is arranged at the bottom of the electrolytic tank body to spray the gas-liquid mixture upward from the bottom to the electrolytic anode and / or electrocatalytic component and / or electrolytic cathode. More preferably, at least two groups of independent electrolytic units are arranged in a stacked manner in the electrolytic tank, and each group of electrolytic units includes an electrolytic power supply, an electrolytic anode, an electrolytic cathode, an electrocatalytic component, or the electrocatalytic performance structure of at least one electrolytic electrode is improved. For a specific embodiment, see the vertical gas-liquid mixing electrochemical reaction device shown in Figure 22. Among them, it is preferred to arrange the electrolysis electrodes according to the chemical properties of the reaction gases: when the gas participating in the reaction is a reducing gas, they are arranged in the order of electrolysis anode, electrolysis cathode, electrolysis anode, and electrolysis cathode; when the gas participating in the reaction is an oxidizing gas, they are arranged in the order of electrolysis cathode, electrolysis anode, electrolysis cathode, and electrolysis anode, so that the gas-liquid mixed electrolytic cell can fully exert the effect of its electrochemical reaction.

[0061] The present invention can also be improved by adding an ultrasonic generator to the electrolytic cell body and / or the electrolytic cell gas-liquid mixer. This ultrasonic generator utilizes the cavitation effect of ultrasound to fully disperse and dissolve bubbles in the electrolyte into the solution, thereby improving the efficiency of the oxidation or reduction reaction. Preferably, the ultrasonic generator is installed on the liquid flow pipeline of the electrolytic cell gas-liquid mixer. This installation structure is simple and can achieve better gas-liquid mixing effects. A specific embodiment is shown in Figure 7. More preferably, the electrolytic cell gas-liquid mixer is made of at least one of stainless steel, titanium, and nickel, so that the ultrasonic generator installed on the electrolytic cell gas-liquid mixer can achieve greater energy efficiency during operation.

[0062] The present invention can further form a gas-liquid hybrid electrochemical reaction system for treating landfill leachate by connecting a gas-liquid hybrid electrolytic cell as the core and various auxiliary devices:

[0063] The present invention can be provided with two or more gas-liquid mixed electrolytic cells, which are connected to form a combination of two-stage or multi-stage gas pipeline series-type gas-liquid mixed electrochemical reaction devices, that is, the front and rear gas-liquid mixed electrochemical reaction devices are connected by gas pipelines, and the gas escaping from the front-stage gas-liquid mixed electrochemical reaction device during the reaction process is collected and drained to the rear-stage gas-liquid mixed electrochemical reaction device for use as a reaction gas raw material, which can reduce production costs and reduce pollution. Preferably, the mixed gas escaping from the reaction of the front-stage electrolytic cell is first washed and separated, and the raw gas obtained after the washing and separation treatment is sent to the rear-stage electrolytic cell for use as a production raw material. The washing liquid used in the washing and separation treatment is water and / or an electrolyte solution, which is specifically selected according to the properties of the gas.

[0064] The present invention can also add a mixed gas separation tank, which is arranged on the gas pipeline of the system of the present invention. The mixed gas separation tank can be a bubbling gas-liquid mixer, a spray tower gas-liquid mixer or a venturi vacuum ejector. The principle is to utilize the gas-liquid mixing process to dissolve the gas components in the mixed gas that are soluble in water or other solvents into water or the solvent, and to separate the other gas components that are insoluble in water or the solvent from the liquid surface, so as to separate two or more mixed gases. Preferably, the combination of a vacuum ejector and a bubbling gas-liquid mixer is used to inject the mixed gas into the solution for separation, which has a better effect. Preferably, a combination of series-type mixed gas separation tanks is provided to perform two-stage or more thorough separation of the mixed gas.

[0065] The present invention can also be configured with an insulated bipolar electrode cage or isolation mesh frame. Multiple bipolar electrodes can be isolated and fixedly stacked in sections using an insoluble insulated bipolar electrode cage or isolation mesh frame during use. This prevents the bipolar electrodes, which are immersed between the electrolytic anode and cathode, from shifting under the impact of liquid flow, ensuring proper electrocatalytic function. A schematic diagram of the bipolar electrode cage structure is shown in Figure 16 , and a specific embodiment is shown as reference numeral 11 in Figure 5 . The cage is made of an insulating rubber mesh or porous mesh.

[0066] The present invention can also be improved as follows: when the output voltage of the adapted electrolytic power supply is higher than the human safety voltage (36V), a photoelectric control system or a human body sensing control system is added to set a dangerous working area. When a living thing enters the controlled area, an alarm is immediately triggered and the electrolytic power supply is shut down.

[0067] The present invention can also add a temporary storage tank to the system for temporarily storing materials.

[0068] The present invention can also add an overflow buffer tank to the system, which is connected to at least one tank body in the system of the present invention to solve the problem of liquid flow between tank bodies. The tank body can be an electrolytic tank, a temporary storage tank or other tank-equipped device.

[0069] The present invention can also add a chemical reaction tank to the system, which is connected to at least one of the electrolytic tank, temporary storage tank, overflow buffer tank, mixed gas separation tank, and other chemical reaction tanks through a pipeline, and is used to perform chemical reaction treatment on the reactants or adjust the pH value of the solution.

[0070] The present invention can also include a polluted exhaust gas treatment tank in the system, which is connected to the exhaust gas outlet of at least one of the gas-liquid hybrid electrochemical reaction device, the temporary storage tank, the overflow buffer tank, the chemical reaction tank, the mixed gas separation tank, and the other polluted exhaust gas treatment tanks via a pipeline to treat the polluted exhaust gas in an environmentally friendly manner. The polluted exhaust gas treatment tank is a spray-type or Venturi-jet-type gas-liquid hybrid treatment tank.

[0071] The present invention can also include a solid-liquid separator in the system, which is connected to at least one of the electrolytic cell, temporary storage tank, overflow buffer tank, chemical reaction tank, mixed gas separation tank, polluted tail gas treatment tank, and other solid-liquid separators via a pipeline to separate the solid-liquid mixture. Specifically, solid-liquid separators include filters, filter presses, and centrifuges.

[0072] The present invention can also include a hot / cold temperature exchanger in the system, located in at least one of the electrolytic cell, the temporary storage tank, and the chemical reaction tank. The hot / cold temperature exchanger is used to control the temperature of the reaction solution and adjust the temperature of the temporary storage solution, ensuring that the temperature of each solution meets process requirements, thereby ensuring safe production and improving reaction efficiency.

[0073] The present invention can also be improved by adding an agitator, which is installed in at least one of the electrolytic cell, temporary storage tank, and chemical reaction tank to achieve uniform temperature and concentration of the reactants, thereby facilitating production process control. Agitators are divided into impeller agitators and liquid flow pump tube agitators.

[0074] The present invention can also be improved as follows: an automatic detection and feeding controller and a sensor are added, the detection signal output end of the sensor is connected to the detection signal input end of the automatic detection and feeding controller, and the control signal output end of the automatic detection and feeding controller is connected to the control signal input end of the electrolysis power supply, valve, pump, ultrasonic generator, hot and cold temperature exchanger and stirrer in the device, so that the device performs sampling data processing according to a pre-programmed program during the production process and controls the addition of chemicals during the reaction process so that the reaction liquid meets the process reaction requirements and operates automatically and safely according to the pre-programmed program. The sensor is selected from at least one of an acidity meter, a pH meter, a hydrometer, an oxidation-reduction potentiometer (ORP meter), a liquid level meter, a voltmeter, an ammeter, a thermometer, a photoelectric colorimeter, a chlorine concentration detector, a hydrogen concentration detector, an ammonia concentration detector, a nitric oxide concentration detector, a nitrogen dioxide concentration detector and a spectrophotometer, and is arranged in at least one of the electrolytic cell, the temporary storage tank, the overflow buffer tank, the chemical reaction tank, the mixed gas separation tank and the polluted tail gas treatment tank.

[0075] The present invention can also be improved as follows: an air pressure balance connecting pipe is added, as shown by reference numeral 56 in FIG. 10 , so that at least one tank area in the electrolytic cell is connected to the air passage to achieve pressure balance with the atmosphere according to process requirements.

[0076] The present invention can also be improved as follows: a common electrolytic cell for preparing gas is added to produce oxidizing gas and / or hydrogen for supplying the gas-liquid mixed electrochemical reaction device, so as to improve the working efficiency of the gas-liquid mixed electrochemical reaction device and reduce production costs.

[0077] The present invention can also be improved as follows: a gas-liquid separation washing tank is added to the gas pipeline of the device of the present invention to separate the bubbles and the solution in the gas-liquid mixture.

[0078] The present invention can also be improved by adding solution guide plates to increase the solution flow area, thereby facilitating the escape of insoluble gases from the electrolyte. These guide plates can be installed below the liquid inlets of various tanks in the system according to process requirements. For example, the two solution guide plates shown in FIG10 are respectively installed below the liquid inlets of the two temporary storage tanks.

[0079] The present invention can also be improved as follows: a bubble drainage hood is added at the electrode in the electrolytic cell, as shown by number 95 in Figure 5, so that the bubbles in the electrolyte can escape along the drainage pipe and be utilized; preferably, the air outlet of the bubble drainage hood is connected to the air inlet of the gas-liquid mixer of the electrolytic cell.

[0080] The present invention can also be improved as follows: a gas-liquid mixing reaction tank is added. The gas-liquid mixing reaction tank shown in Figure 12 is one of its embodiments, which is composed of a tank body and a gas-liquid mixer combining ordinary vacuum jet type and bubbling type. The gas-liquid mixer 7-3p is composed of an ordinary bubbling type gas-liquid mixer 7-2p added to the outlet of the ordinary vacuum jet gas-liquid mixer 7-1p. The additional gas-liquid mixing reaction tank is used to be connected to at least one of the electrolytic cell, temporary storage tank, overflow buffer tank, chemical reaction tank, mixed gas separation tank, polluted tail gas treatment tank, and other gas-liquid mixing reaction tanks through a pipeline, and ozone and / or chlorine are used to oxidize the landfill leachate.

[0081] The present invention can also be improved as follows: in the system of the present invention, a hydrogen tail gas high altitude discharge pipe is added to at least one hydrogen outlet to discharge the hydrogen-containing tail gas safely.

[0082] The present invention can also be improved as follows: an electric furnace is added to perform high-temperature treatment on the iron hydroxide precipitate containing only organic impurities, and the iron oxide obtained after the high-temperature treatment is used as other raw materials.

[0083] The second object of the present invention is achieved through the following technical solutions.

[0084] A method for treating landfill leachate using the above-mentioned gas-liquid hybrid electrochemical reaction device is characterized by comprising the following steps:

[0085] (1) Using the gas-liquid hybrid electrochemical reaction device, using the liquid to be treated as the electrolyte of the gas-liquid hybrid electrolytic cell or as the electrolyte of at least one cell zone in the electrolytic cell, and connecting the electrolysis power supply; the liquid to be treated is landfill leachate and / or landfill leachate that has been pre-treated;

[0086] (2) starting at least one electrolytic cell gas-liquid mixer, drawing oxidizing gas and / or reducing gas into the treated liquid for gas-liquid mixing, and then contacting the mixed gas with at least one of the electrolytic anode and / or electrolytic cathode with improved electrocatalytic structure and the electrocatalytic component, and utilizing the electrocatalytic component to exert electrocatalytic effect to oxidize and / or reduce the substances to be treated in the treated liquid.

[0087] Among them, when power is applied for electrolysis, the gas-liquid mixture containing the oxidizing gas is brought into contact with the negatively charged components in the gas-liquid hybrid electrolytic cell to react, and the treated liquid is brought into contact with the positively charged components in the device to perform an oxidation reaction; and / or when power is applied for electrolysis, the gas-liquid mixture containing the reducing gas is brought into contact with the positively charged components in the gas-liquid hybrid electrolytic cell to react, and the treated liquid is brought into contact with the negatively charged components in the device to perform at least one of a hydrogenolysis reaction, a hydrogenation reaction, and a reduction reaction.

[0088] The gas-liquid hybrid electrolytic cell of the present invention can be selected from a non-divided electrolytic cell or an electrolytic cell with an electrolytic separator according to the process design. When an electrolytic cell separator is provided in the cell, the electrolytic cell is divided into at least two cell areas. Preferably, the electrolytic cell separator is a reverse osmosis membrane, so that during the electrolysis operation, the electrolyte in the cathode and anode cell areas mainly undergoes water electrolysis reaction, causing oxygen to be electrolyzed at the anode and hydrogen ions to react with NO3 at the cathode. - Chemical reaction, the oxygen produced by electrolysis can be supplied to the ozone generator.

[0089] The pre-treated landfill leachate in step (1) is landfill leachate that has undergone chemical reaction and / or physical treatment but still needs to be further treated for environmental protection, specifically landfill leachate that has undergone at least one of chemical reaction, pH adjustment, component addition, component concentration adjustment, and solid-liquid separation.

[0090] The oxidizing gas described in step (2) is at least one selected from ozone, oxygen, and chlorine. The reducing gas is hydrogen. The gases participating in the reaction in the present invention are divided into self-electrolysis gas and external input gas. The self-electrolysis gas and the electrolyte mixed with it are both from the same tank area of ​​the same electrolytic cell; the external input gas and the electrolyte mixed with it are from different tank areas of the same electrolytic cell, or from outside the electrolytic cell. Among them, ozone is an external input gas, while oxygen, chlorine, and hydrogen can be either external input gases or self-electrolysis gases.

[0091] In step (1) and step (2), a gas-liquid hybrid electrochemical reaction device is used in combination with an oxidizing gas to perform an electrochemical oxidation reaction on the landfill leachate and / or the landfill leachate that has been pre-treated, so that the nitrogen pollutants therein are converted into at least one of nitrogen, nitrogen oxides, and nitrates under electrocatalysis, and the organic amines therein are further oxidized and degraded; and / or a gas-liquid hybrid electrochemical reaction device is used in combination with a reducing gas to perform a hydrogenolysis reaction and / or a hydrogenation reaction on the landfill leachate and / or the landfill leachate that has been pre-treated under electrocatalysis, and a reduction reaction is performed on the nitrate nitrogen therein, so that the concentration of nitrogen pollution in the landfill leachate is reduced or eliminated.

[0092] When the present invention uses a gas-liquid hybrid electrochemical reaction device to absorb oxidizing gas to oxidize landfill leachate and / or pre-treated landfill leachate, in addition to the electrochemical oxidation reaction occurring under the electrocatalysis of the gas-liquid hybrid electrochemical reaction device during the electrolysis process, a reaction in which the oxidizing gas oxidizes the landfill leachate and / or pre-treated landfill leachate also occurs. The nitrogen pollutants in the reaction solution undergo the following electrochemical oxidation reaction on the positively charged components of the gas-liquid hybrid electrochemical reaction device when power is applied to perform electrolysis: 2NH3 + 6[OH] - -6e- →6H2O+N2NO2 - +2[OH] - -2e - →H2O+NO3 -

[0093] When the electrolyte is acidic, in addition to the above reaction, the nitrate ions generated above show oxidizing properties and undergo the following redox reaction with inorganic ammonia NH3 in the solution: 5NH3+3HNO3→9H2O+4N2

[0094] The present invention uses a gas-liquid hybrid electrochemical reaction device to absorb hydrogen and perform at least one of hydrogenolysis, hydrogenation, and reduction reactions on landfill leachate and / or landfill leachate that has been pre-treated. When the gas-liquid hybrid electrochemical reaction device is energized for electrolysis, the hydrogen is converted into protons H at the positively charged components through electrocatalysis. + Participate in the reaction, the electrochemical reaction formula is: H2-2e - →2H + ; and / or hydrogen reacts chemically with oxidizing substances in the electrolyte under the electrocatalysis of the negatively charged component when the gas-liquid hybrid electrochemical reaction device is powered on for electrolysis. Thanks to the electrocatalytic conditions provided by the gas-liquid hybrid electrochemical reaction device, hydrogen can react with landfill leachate and / or pre-treated landfill leachate under normal pressure to undergo hydrogenolysis and / or hydrogenation, promoting the decomposition of organic amines and the removal of NO2 in the reaction solution. - 、NO3 - Perform electrochemical reduction reaction.

[0095] Among them, NO2 - and NO3 - When the gas-liquid hybrid electrochemical reaction device is energized for electrolysis, the following electrochemical reduction reaction occurs under the electrocatalysis of the negatively charged components: - +2H + +2e - →2OH - +2NO↑ 2NO2 - +6H + +6e - →2OH - +2H2O+N2↑ 2NO2 - +12H + +12e - →2OH - +2H2O+2NH3 2NO3 - +6H + +6e - →2OH - +2H2O+2NO↑ 2NO3 -+10H + +10e - →2OH - +4H2O+N2↑ 2NO3 - +16H + +16e - →2OH - +4H2O+2NH3

[0096] Preferably, to play the role of NO2 - and NO3 - The oxidizing properties of the electrolytic reaction solution can better improve the reduction reaction rate under electrocatalysis, and the electrolytic reaction solution is adjusted to a pH value of less than 7 using hydrochloric acid and / or sulfuric acid, and the acidity of the electrolytic reaction solution set in the process is maintained during the reaction, so that the reaction can proceed continuously and efficiently. More preferably, the pH value of the electrolytic reaction solution is adjusted to a range of 0.01 to 6.5. Even more preferably, the pH value of the reaction solution is adjusted to a range of 1 to 5. A higher lower limit of pH value can save reaction raw materials and can be monitored using a conventional pH meter. Nitrite NO2 - and nitrate NO3 - It shows oxidizing properties in acidic solution environment and is more easily reduced.

[0097] To further effectively treat nitrogen contamination in landfill leachate and / or pre-treated landfill leachate, an oxidizing gas is used for oxidation and a reducing gas is used for at least one of hydrogenolysis, hydrogenation, and reduction. The oxidizing gas can be absorbed by an electrolytic cell gas-liquid mixer, or directly introduced for oxidation, or the two oxidation methods can be used sequentially. The method of the present invention does not require the order in which the landfill leachate is oxidized using an oxidizing gas and the landfill leachate is subjected to hydrogenolysis and / or hydrogenation and / or reduction reactions using a reducing gas, and can be flexibly arranged according to the process.

[0098] A preferred solution in the treatment method of the process of the present invention is to directly add ozone and / or chlorine to the treated liquid for oxidation reaction, and use a gas-liquid mixed electrochemical reaction device to perform an electrocatalytic reduction reaction on it, which not only achieves the purpose of oxidation treatment but also reduces equipment investment and simplifies process control. The above-mentioned oxidation reaction and the use of reducing gas for hydrogenolysis reaction and / or hydrogenation reaction and / or reduction reaction have no requirements for the order of treatment, and can be flexibly arranged according to the process. Preferably, the gas-liquid mixed reaction tank of the existing technology is used to directly mix ozone and / or chlorine into the treated liquid for oxidation reaction.

[0099] Among them, compared with chlorine, ozone shows higher oxidation performance in the oxidation reaction of landfill leachate under the same conditions. The ozone gas is produced by using an ozone generator to convert oxygen or air into ozone through the action of a high-frequency and high-voltage electric field. Preferably, ozone is produced using oxygen, and the oxygen comes from one or more of commercial oxygen, oxygen produced by ordinary chemical reactions, and oxygen produced by electrolysis reactions. Oxygen from one of the above sources can be used alone or more than one of the above sources can be mixed and used. When ozone is produced by an ozone generator using oxygen produced by electrolysis, the oxygen is first pre-washed and condensed and dried to avoid affecting the normal operation of the ozone generator.

[0100] The chlorine gas is derived from one or more of commercial chlorine gas, chlorine gas produced by common chemical reaction, and chlorine gas produced by electrolytic reaction, and the chlorine gas from the above sources is used alone or after mixing more than one of the above sources.

[0101] The landfill leachate and / or pre-treated landfill leachate can react with ozone under acidic, alkaline, or neutral conditions. However, the reaction with chlorine in an acidic environment can easily generate nitrogen trichloride, a highly explosive substance. Therefore, the reaction with chlorine in an alkaline environment is preferred.

[0102] During the ozone treatment of landfill leachate and / or pre-treated landfill leachate, nitrogen-containing pollutants are mainly oxidized to produce carbon dioxide, water, nitrogen and / or nitrogen oxide gas and / or nitrate, which may be accompanied by the generated oxygen and residual trace amounts of ozone escaping from the reaction solution. The chemical reaction equation for the above reaction is shown below, where R-NH X Refers to organic amines. R-NH X +O3→CO2↑+N2↑+O2↑+H2O 6NH3+7O3→9H2O+6NO2↑ 3NO+O3→3NO2↑ 2NO+O2→2NO2↑ NO2 - +O3→NO3 - +O2↑

[0103] When landfill leachate and / or pre-treated landfill leachate contains hypophosphite and reacts with ozone, the following reactions also occur: PO2 3- +O3→PO3 3- +O2↑ PO3 3- +O3→PO4 3- +O2↑

[0104] When chloride ions exist in landfill leachate and / or pre-treated landfill leachate and react with ozone under acidic conditions, in addition to the above reactions, nitrogen trichloride, an explosive substance, will also be generated. If the landfill leachate contains S 2-ions, and hydrogen sulfide will be released. - +O3→ClO - +O2↑ HCl+HClO→Cl2↑+H2O NH4Cl+3Cl2→NCl3+4HCl

[0105] Oxidation of landfill leachate and / or pre-treated landfill leachate using an oxidizing gas under alkaline conditions can prevent the generation of explosive and highly toxic substances such as nitrogen trichloride and hydrogen sulfide during the reaction due to the presence of chlorine and sulfur compounds in the acidic reaction liquid, effectively ensuring production safety. Therefore, during the reaction of landfill leachate and / or pre-treated landfill leachate with an oxidizing gas, the pH of the reaction liquid is preferably controlled to be no less than 7; more preferably, the pH of the reaction liquid is controlled to be within the range of 8 to 14; and even more preferably, the pH of the reaction liquid is controlled to be within the range of 8.5 to 11. When an alkaline substance is added to the landfill leachate and / or pre-treated landfill leachate to adjust its pH, the alkaline substance is at least one selected from sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

[0106] Landfill leachate and / or pre-treated landfill leachate contains chloride ions Cl - and / or sulfide ions S 2- When reacting with ozone under alkaline conditions, the formation of nitrogen trichloride and hydrogen sulfide can be avoided, and the following chemical reaction occurs, where M represents a metal element: Cl - +O3→ClO - +O2↑ NaCl+HClO→NaOH+Cl2↑ 2NH3+3ClO - →3Cl - +3H2O+N2↑ S 2- +O3+H2O→H2SO4 M +n +n(OH) - →M(OH)n↓ M +n +CO3 2- →M(CO3)n2↓

[0107] When using chlorine to oxidize landfill leachate and / or pre-treated landfill leachate under alkaline conditions, if the landfill leachate contains NH3, NO2 - Impurities mainly undergo the following chemical reactions: Cl2+NaOH→NaClO+HCl 2NH3+3NaClO→3NaCl+3H2O+N2↑ NO2 - +ClO - →NO3 - +Cl -

[0108] When landfill leachate and / or pre-treated landfill leachate contains hypophosphite, the following reaction also occurs: PO2 3- +ClO - →PO3 3- +Cl - PO3 3- +ClO - →PO4 3- +Cl -

[0109] To remove inorganic ammonia NH3 from landfill leachate and / or pre-treated landfill leachate, it is preferred to directly oxidize it with chlorine under alkaline conditions to reduce treatment costs. To remove organic amine contaminants from landfill leachate and / or pre-treated landfill leachate, it is preferred to directly oxidize it with ozone under alkaline conditions to more effectively oxidize and degrade the organic contaminants. However, when landfill leachate and / or pre-treated landfill leachate contains inorganic ammonia NH3, ozone will oxidize the inorganic ammonia NH3 into nitrogen oxides rather than nitrogen gas, increasing the subsequent treatment pressure. In this case, it is preferred to oxidize it with chlorine, or first with chlorine and then with ozone. Furthermore, during the reduction reaction of landfill leachate and / or pre-treated landfill leachate using a gas-liquid hybrid electrochemical reactor, NH3 impurities may be generated in the reaction liquid. If the process treatment target is not achieved, chlorine gas may be used to directly oxidize the reaction liquid under alkaline conditions to remove the ammonia NH3.

[0110] When an oxidizing gas is used to oxidize landfill leachate and / or pre-treated landfill leachate, the main components of the escaping tail gas are CO2, O2, N2, and NO2. When chloride ions are present in the treated liquid, Cl2 may also be present in the tail gas. The gas escaping from the reaction liquid is subjected to the first stage of tail gas treatment using an alkaline solution or clean water as a tail gas absorption reaction liquid to generate nitric acid and / or nitrates. Preferably, sodium hydroxide and / or potassium hydroxide solution is selected as the tail gas absorption reaction liquid for the first stage of tail gas treatment. The following chemical reactions occur using potassium hydroxide tail gas absorption liquid as an example: Cl2 + 2KOH → 2KClO + KCl + H2O CO2 + 2KOH → K2CO3 + H2O 3NO2 + H2O → 2HNO3 + NO 2NO + O2 → 2NO2 NO + KClO → KCl + NO2 HNO3 + KOH → KNO3 + H2O

[0111] Preferably, the chlorine and nitrogen oxide gases in the tail gas are separated and treated in stages. First, an acidic ferrous chloride and / or ferrous sulfate solution is used as the tail gas absorption reaction liquid in the first stage of tail gas treatment to absorb the chlorine in the tail gas, producing ferric chloride and / or ferric sulfate, which can be used as other raw materials. During this process, at least one of the following chemical reactions occurs: 3Cl2+6FeSO4→2Fe2(SO4)3+2FeCl3 Cl2+2FeCl2→2FeCl3 3NO2+H2O→2HNO3+NO↑ NO3 - +4H + +3Fe 2+ +3e - →3Fe 3+ +2H2O+NO↑

[0112] Then when the first section tail gas treatment is conducted, the tail gas that emanates comprises nitric oxide gas is collected and an alkaline solution or clear water is adopted as the tail gas absorption reaction liquid of the second section tail gas treatment to absorb it and process it for environmental protection. The tail gas absorption liquid that the second section tail gas treatment adopts preferably adopts potassium hydroxide solution, and when the drainage first section tail gas treatment emanates the tail gas that contains nitric oxide gas, at least one of air, oxygen, and hydrogen peroxide is introduced into potassium hydroxide solution and jointly carries out chemical reaction, so that the nitric oxide gas in the tail gas emanating from the first section tail gas treatment is dissolved in the tail gas absorption reaction liquid of the second section tail gas treatment and reacts to generate nitrogen dioxide and then reacts with potassium hydroxide solution to obtain potassium nitrate. When introducing hydrogen peroxide in the second section tail gas treatment, preferably under the safety control of an oxidation-reduction potentiometer, add to the potassium hydroxide tail gas absorption liquid. The following chemical reactions mainly occur in the above process: 2NO+O2→2NO2 or NO+H2O2→NO2+H2O 3NO2+H2O→2HNO3+NO↑ KOH+HNO3→KNO3+H2O

[0113] In order to completely eliminate the small amount of nitrogen monoxide pollutants released during the second stage of tail gas treatment, a third or more stages of tail gas treatment can be added to treat the small amount of nitrogen monoxide tail gas.

[0114] The present invention can also be improved as follows: after oxidizing the landfill leachate and / or the pre-treated landfill leachate with chlorine, the following two schemes are used to remove the residual chlorine and hypochlorite in the reaction liquid so that the reaction liquid can smoothly proceed to the next chemical reaction:

[0115] Option 1: Add a ferrous compound to the reaction solution to remove residual chlorine and hypochlorite therein, and then perform solid-liquid separation under the condition that the pH value of the reaction solution is greater than 7. Preferably, the ferrous compound used to remove residual chlorine and hypochlorite in the reaction solution is at least one selected from ferrous hydroxide, ferrous carbonate, ferrous sulfate, and ferrous chloride. Preferably, the pH value of the reaction solution is set to no less than 10.5 after the addition of the ferrous compound, so as to utilize the added Fe 2+ This reduces the high-valent chromium or manganese ions in the reaction solution to low-valent ions, converting most of the heavy metal ions in the reaction solution into insoluble hydroxides and / or carbonate precipitates. Solid-liquid separation is then performed to remove the heavy metal ions from the reaction solution. This solid-liquid separation process also removes insoluble phosphates from the reaction solution, achieving phosphorus removal. The resulting filter residue contains organic impurities in addition to the aforementioned pollutants and should be treated as hazardous waste.

[0116] Option 2: Add hydrochloric acid and / or sulfuric acid to the reaction solution to lower its pH to below 7, converting the hypochlorite in the reaction solution into hypochlorous acid and continuing to effectively degrade the organic pollutants in the reaction solution through acidic oxidation. Under acidic conditions, chlorine reacts with water to produce hydrochloric acid and hypochlorous acid. Any hypochlorous acid that does not react with the organic pollutants gradually decomposes into hydrochloric acid and oxygen.

[0117] The present invention can also be improved by adding a protein removal step, wherein hydrochloric acid and / or sulfuric acid is added to the landfill leachate and / or pre-treated landfill leachate to adjust the pH to below 6, preferably within the pH range of 1 to 3.5, so that proteins, one of the nitrogen-containing contaminants, coagulate and can be removed through solid-liquid separation. The filter residue obtained from this solid-liquid separation should be treated as hazardous waste. Preferably, before adding hydrochloric acid and / or sulfuric acid to the landfill leachate and / or pre-treated landfill leachate for protein removal, a small amount of hydrogen peroxide is added to kill pathogens therein, as a measure to ensure occupational safety and health.

[0118] The present invention can also be improved as follows: after the landfill leachate and / or the landfill leachate that has been pre-treated is subjected to at least one of hydrogenolysis, hydrogenation and reduction reactions using a gas-liquid hybrid electrochemical reaction device, a ferrous compound and NO3 in the reaction solution are added to the reaction solution under acidic conditions. - The pollutants react to reduce NO3 in the reaction solution - Concentration. The method is used to eliminate NO3 in the reaction solution. - The ferrous compound of the pollutant is at least one selected from ferrous sulfate, ferrous chloride, ferrous hydroxide, and ferrous carbonate. Its chemical reaction formula is as follows: 3Fe 2+ +NO3 - +4H + →3Fe 3++2H2O+NO↑

[0119] Preferably, ferrous compounds are used to remove NO3 in the reaction solution. - When the pH value of the reaction solution is adjusted to an appropriate range set by the process, ferrous compounds and hydrogen peroxide are added multiple times or continuously to carry out a Fenton oxidation reaction, so that the organic pollutants in the reaction solution are oxidatively degraded. More preferably, an alkaline substance is added to the reaction solution after the Fenton reaction to adjust the pH value of the reaction solution, so that ferric hydroxide, heavy metal hydroxides and / or heavy metal carbonates, and phosphate precipitates are generated in the reaction solution, and the ferric hydroxide filter residue containing heavy metals, organic pollutants, and phosphorus compounds is removed by solid-liquid separation. The resulting filtrate is subjected to the next treatment, and the filter residue should be treated as hazardous waste.

[0120] The present invention can also be improved as follows: the iron hydroxide precipitate residue obtained in the process of treating landfill leachate and / or pre-treated landfill leachate, which does not contain heavy metals and phosphorus compounds but only contains organic pollutants, is subjected to high-temperature treatment to decompose the organic pollutants therein at high temperature, and an iron oxide product is obtained which can be used as other raw materials.

[0121] The present invention can also be improved as follows: During operation using a gas-liquid hybrid electrochemical reaction device, since the gas-liquid mixture is sprayed onto the electrocatalytic component and / or electrolytic electrode for reaction, bubbles in the reaction liquid are prone to blocking the normal migration of ions in the electrolyte, thereby affecting the operating efficiency of the electrolytic cell. Therefore, it is necessary to adjust the operating voltage and current values ​​based on the structure of the electrolytic cell, the amount of self-electrolyzed gas during the electrolysis reaction, and the amount of external input gas. The operating voltage and current values ​​of the gas-liquid hybrid electrochemical reaction device can indirectly reflect the relationship between the amount of gas involved in the reaction and the bubble barrier rate in the electrolyte. Therefore, by adaptively adjusting the operating voltage and current, the power factor of the device is improved.

[0122] The present invention can also be improved as follows: while the cathode region of the electrolytic cell in the gas-liquid hybrid electrochemical reaction device is used as a device for electrochemically reducing landfill leachate and / or pre-treated landfill leachate, the anode region of the electrolytic cell is used to electrochemically oxidize the organic waste liquid and / or electrolyze oxygen for use in the ozone generator. The organic waste liquid can be one or a mixture of more than one of landfill leachate, pre-treated landfill leachate, or other organic waste liquids.

[0123] The present invention can also be improved by adding an inorganic ammonia removal step, specifically heating and stirring the landfill leachate and / or pre-treated landfill leachate under alkaline conditions to convert the inorganic ammonia NH₄OH therein into ammonia gas NH₃, which is then driven out and removed. The released ammonia gas NH₃ can be centrally disposed of for environmental protection.

[0124] The present invention can also be improved as follows: in order to make the reaction liquid in the process of treating landfill leachate and / or pre-treated landfill leachate safe and controllable, the temperature of the reaction liquid is regulated by using a hot and cold temperature exchanger to meet the process temperature requirements.

[0125] The present invention can also be improved as follows: To ensure safe and controllable chemical reactions during the treatment of landfill leachate and / or pre-treated landfill leachate, an automatic detection and feeding controller and sensors are used to operate the device for sampling and testing and controlled feeding of chemical reactants, so that the device can operate safely according to pre-programmed procedures. The sensors include a pH meter, an acidity meter, a thermometer, a liquid level gauge, a hydrometer, a photoelectric colorimeter, an oxidation-reduction potentiometer (ORP meter), a nitric oxide gas concentration meter, a nitrogen dioxide gas concentration meter, an ozone flow meter, a chlorine flow meter, a chlorine concentration meter, and a hydrogen concentration meter.

[0126] Compared with the prior art, the present invention has the following beneficial effects:

[0127] 1. The gas-liquid hybrid electrochemical reaction device of the present invention has an efficient electrocatalytic effect by providing an electrolytic cell gas-liquid mixer and improving the electrocatalytic structure. It can use hydrogen at normal pressure to efficiently treat nitrogen pollutants in landfill leachate using chemical and physical reaction methods. During the process, phosphorus-containing compounds, heavy metal ions, and organic pollutants can be treated together, thus solving the pollution problem of landfill leachate.

[0128] 2. The present invention is a process that uses a gas-liquid mixed electrochemical reaction device to treat nitrogen pollutants in organic wastewater by physical and chemical methods. Compared with existing biological treatment processes, its workshop occupies a small area and the investment scale of treatment equipment is small. It has the characteristics of easy development, low investment and good effect.

[0129] 3. The present invention solves the problems of incomplete treatment of landfill leachate by the existing reverse osmosis process and high cost of high-temperature combustion treatment of concentrated waste liquid.

[0130] 4. The present invention is safe, reliable and easy to operate, and the device can be used to treat landfill leachate in any occasion.

[0131] 5. The method of the present invention does not add any new pollution sources during the treatment process. During the process, the escaped nitrogen oxide pollution gas can be converted into potassium nitrate solution for reuse; the escaped chlorine tail gas can be collected and treated to obtain trivalent iron salt for reuse as raw material; and the iron hydroxide filter residue containing only organic pollutants can be reused after high-temperature treatment.

[0132] 6. The method of the present invention complies with the National Safety Production Law and can increase the use of oxidants in the treatment process to kill pathogens in the landfill leachate, thereby reducing the spread of pathogens in the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0133] FIG1 is a schematic diagram of a type A gas-liquid hybrid electrochemical reaction device according to Example 1 of the present invention.

[0134] FIG2 is a schematic diagram of a type A device of a gas-liquid mixing electrochemical reaction device according to Example 2 of the present invention.

[0135] FIG3 is a schematic diagram of a type B device of a gas-liquid hybrid electrochemical reaction device according to Example 3 of the present invention.

[0136] FIG4 is a schematic diagram of a C-2 type device of a gas-liquid mixing electrochemical reaction device according to Example 4 of the present invention.

[0137] FIG5 is a schematic diagram of a C-1 type device of a gas-liquid mixed electrochemical reaction device according to Example 5 of the present invention.

[0138] FIG6 is a schematic diagram of a C-1 type device of a gas-liquid mixed electrochemical reaction device according to Example 6 of the present invention.

[0139] FIG7 is a schematic diagram of a C-2 type device of a gas-liquid mixed electrochemical reaction device according to Example 7 of the present invention.

[0140] FIG8 is a schematic diagram of a gas-liquid hybrid electrochemical reaction device according to Example 8 of the present invention.

[0141] FIG9 is a schematic diagram of a gas-liquid hybrid electrochemical reaction device according to Example 9 of the present invention.

[0142] FIG10 is a schematic diagram of a gas-liquid hybrid electrochemical reaction device according to Example 10 of the present invention.

[0143] FIG11 is a schematic diagram of a gas-liquid hybrid electrochemical reaction device according to Example 11 of the present invention.

[0144] FIG12 is a schematic structural diagram of a gas-liquid mixing reaction tank.

[0145] FIG13 is a schematic diagram of the structures of two bipolar electrodes of different shapes.

[0146] FIG14 is a schematic diagram of the structures of four insoluble conductors of different shapes.

[0147] FIG15 is a schematic structural diagram of the gas-liquid mixed electrochemical reaction device and the slot-frame metal mesh bipolar electrode of the present invention.

[0148] FIG16 is a schematic diagram of a bipolar electrode cage.

[0149] FIG17 is a schematic diagram of a gas-liquid mixed electrochemical reaction device for treating landfill leachate according to Example 12 of the present invention.

[0150] FIG18 is a schematic diagram of a gas-liquid mixed electrochemical reaction device for treating landfill leachate according to Example 13 of the present invention.

[0151] FIG19 is a schematic diagram of the structure of the gas-liquid hybrid electrochemical reaction device of Example 14. FIG19-1, FIG19-2, and FIG19-3 are respectively the first, second, and third partial views of FIG19, that is, the three views constitute the complete schematic diagram of the structure of the gas-liquid hybrid electrochemical reaction device of Example 14.

[0152] FIG20 is a schematic diagram of the structure of the gas-liquid hybrid electrochemical reaction device of Example 15. FIG20-1, FIG20-2, and FIG20-3 are respectively the first, second, and third partial views of FIG20 , that is, the three figures constitute the complete gas-liquid hybrid electrochemical reaction device and process flow diagram of Example 15.

[0153] FIG21 is a schematic diagram of the structure of the gas-liquid hybrid electrochemical reaction device of Example 16. FIG21-1, FIG21-2, FIG21-3, FIG21-4, and FIG21-5 are respectively the first, second, third, fourth, and fifth partial views of FIG21 , that is, the five figures constitute the complete schematic diagram of the structure of the gas-liquid hybrid electrochemical reaction device of Example 16.

[0154] Reference numerals:

[0155] Reference numerals:

[0156] 1. Electrolytic cell body, 2-Electrolytic cell separator 1 #, 3-electrolysis anode, 4-electrolysis cathode, 5-electrolysis power supply, 6-bipolar electrode, 7-vacuum jet electrolytic cell gas-liquid mixer, 8-bubbling electrolytic cell gas-liquid mixer, 9-vacuum jet and bubbling combined electrolytic cell gas-liquid mixer, 10-trough frame metal mesh bipolar electrode, 11-bipolar electrode stacking fixed electrical insulation box, 12-insulating through-hole support baffle, 13-gas-liquid separation washing tank, 14-ordinary bubbling gas-liquid mixer, 15-ordinary vacuum jet gas-liquid mixer, 16-ordinary spray tower gas-liquid mixer, 17-cold and hot temperature exchanger, 18-impeller agitator, 19 -Liquid flow agitator, 20-temporary storage tank, 21-chemical reaction tank, 22-overflow buffer tank, 23-insoluble anode conductor, 24-insoluble cathode conductor, 25-ultrasonic generator, 26-solid-liquid separator, 27-polluted tail gas treatment tank, 28-sealed tank cover for collecting escaped gas from electrolytic cell reaction, 29-sealed tank cover plate hydrogen discharge pipe port, 30-sealed tank cover plate oxidizing gas discharge pipe port, 31-hydrogen, 32-oxidizing gas, 33-oxygen, 34-chlorine, 35-nitric oxide, 36-nitrogen dioxide, 37-nitrogen, 38-carbon dioxide, 39-ammonia, 40 - ammonia, 41- ozone, 42- landfill leachate, 43- coagulated protein solids, 44- pre-treated landfill leachate, 45- waste liquid containing nitrogen pollutants, 46- reaction liquid requiring treatment, 47- anolyte, 48- catholyte, 49- alkaline solution, 50- acidic solution, 51- exhaust pipe of gas-liquid mixed electrolytic cell, 52- valve, 53- pump, 54- sealing screw, 55- gas booster pump, 56- air pressure equalization connecting pipe, 57- ordinary electrolytic cell, 58- water, 59- mixed gas, 60- gas escaping after separation of mixed gas, 61- dissolved in water reaction products, 62-electrical insulator, 63-conductor, 64-conductive connecting wire, 65-automatic detection and feeding controller, 66-sensor, 67-solution flow area expansion guide plate or solid sediment baffle, 68-support frame, 69-mixed gas gas-liquid separator, 70-refrigeration machine, 71-hydrogen peroxide, 72-ferrous salt, 73-filter residue, 74-filtrate, 75-intermediate tank area, 76-intermediate tank electrolyte, 77-safety photoelectric control alarm system, 78-heater, 79-oxygen cylinder, 80-chlorine cylinder, 81-hydrogen cylinder, 82-nitrogen cylinder, 83-electrolytic cell partition 2 #Filter cloth, filter screen, water-permeable non-ion selective diaphragm, 84-separator-free gas-liquid mixing electrolytic cell, 85-electrolytic cell electric field line channel, 86-carbon dioxide gas cylinder, 87-carbon monoxide gas cylinder, 88-gas cylinder, 89-electrolyte ion current interrupter, 90-electrolytic electrode, 91-reducing gas, 92-gas-liquid mixer multi-way air inlet pipe component, 93-bubble reaction liquid guide cover, 94-electrolysis gas, 95-bubble drainage cover in electrolyte, 96-insulating partition plate in electrolytic cell, 97-ozone generator, 98-hydrogen-containing tail gas high-altitude discharge pipe, 99-sodium chloride solution, 100-filter residue, 101-electric heating furnace, 102-nozzle.

[0157] In the drawings and the following embodiments, multiple components of the same component type in a device are represented by "reference numerals." For example, electrolytic cell body 1-1 refers to one electrolytic cell body, and electrolytic cell body 1-2 refers to another electrolytic cell body. When there are three or more components of the same component type, "~" is used for abbreviation. For example, electrolytic cell bodies 1-1, 1-2, and 1-3 are referred to as electrolytic cell bodies 1-1 to 1-3, or 1-1 to 3. DETAILED DESCRIPTION

[0158] The present invention will be further described below through specific embodiments.

[0159] The gas-liquid mixing electrolytic cell, mixed gas separation tank, electrolytic anode, electrolytic cathode, bipolar electrode, bipolar electrode insulating mesh box, electrolytic cell gas-liquid mixer, agitator, temporary storage tank, overflow buffer tank, tail gas treatment tank, insoluble anode conductor, insoluble cathode conductor, and electrolyte ion current interrupter used in the embodiments of the present invention are all manufactured by Yegao Environmental Protection Equipment Manufacturing Co., Ltd. in Foshan, Guangdong Province, China. The solid-liquid separator, sensor, automatic detection and feeding controller, valve, pump, and chemical raw materials are all commercially available products. The gas detectors for ammonia, hydrogen, and chlorine are all products of Xi'an Huafeng Safety Instrument Co., Ltd. in Shaanxi Province, China.

[0160] In addition to the above-mentioned products, those skilled in the art may also select other products with similar properties to the above-mentioned products listed in the present invention according to routine selection, and all of them can achieve the purpose of the present invention.

[0161] Example 1

[0162] The gas-liquid hybrid electrochemical reaction device shown in FIG1 is Example 1 of the present invention, which is a type A gas-liquid hybrid electrolytic cell, and is composed of an electrolytic cell body 1, a sealed tank cover 28 for collecting the gas released by the electrolytic cell reaction, an electrolytic cell separator 2, an electrolytic anode 3 and an electrolytic cathode 4, an electrolytic power supply 5, an electrocatalytic component, and an electrolytic cell gas-liquid mixer. According to the requirements of the oxidation or reduction reaction, the positions of the electrolytic anode 3 and the electrolytic cathode 4 can be interchanged, so the electrolytic electrode 90-1 is the electrolytic anode or the electrolytic cathode, and the electrolytic electrode 90-2 is the corresponding other electrode. Among them, the electrolytic cell separator 2 adopts the electrolytic cell separator 1. # , the electrolytic cell body 1 is divided into an anode cell area and a cathode cell area. When the electrolytic electrode 90-1 is the electrolytic anode, the sealed cell cover 28 for collecting the escaping gas from the electrolytic cell reaction only covers the anode cell area, and two electrocatalytic components, namely bipolar electrodes, are set in the anode cell area, both of which are immersed in the electrolyte in the anode cell area; when the electrolytic electrode 90-1 is the electrolytic cathode, the sealed cell cover 28 for collecting the escaping gas from the electrolytic cell reaction only covers the cathode cell area, and two electrocatalytic components, namely bipolar electrodes 6, are set in the cathode cell area, both of which are immersed in the electrolyte in the cathode cell area; the electrolyte in the anode cell area and the electrolyte in the cathode cell area are the reaction liquids that need to be treated respectively; the gas-liquid mixer of the electrolytic cell adopts a vacuum pump. The air jet type electrolytic cell gas-liquid mixer 7 has an air inlet, a liquid inlet and an outlet, and the air inlet and the liquid inlet are respectively connected to the top and the bottom of the anode cell area, or to the top and the bottom of the cathode cell area, that is, this embodiment uses the electrolysis gas generated in the anode cell area and the electrolyte in the anode cell area to mix the gas and liquid, and sprays it through the outlet extending above the electrolyte surface of the anode cell area and toward the electrocatalytic component, i.e., the bipolar electrode 6, or uses the electrolysis gas generated in the cathode cell area and the electrolyte in the cathode cell area to mix the gas and liquid and sprays it through the outlet extending above the electrolyte surface of the cathode cell area and toward the electrocatalytic component, i.e., the bipolar electrode 6. Due to the presence of sufficient gas, this gas-liquid mixture can promote active electrochemical reactions in the landfill leachate being treated. The positively charged components convert electrical energy into chemical energy, electrocatalytically oxidizing reducing substances in the electrolyte. They also oxidize oxygen, hydroxide ions, chloride ions, and the like in the electrolyte to produce large quantities of superoxide radicals (O2·), hydroxyl radicals (OH·), and / or chlorine radicals (Cl·), chloroxyl radicals (ClO·), and other oxidizing free radicals, rapidly oxidizing substances in the electrolyte that require oxidation treatment, such as oxidizable organic matter and inorganic ammonia in the landfill leachate. The negatively charged components convert electrical energy into chemical energy, electrocatalytically reducing oxidizable substances in the electrolyte. They also produce large quantities of hydrogen radicals (H·) or protons, which rapidly induce at least one of hydrogenolysis, hydrogenation, and reduction reactions on substances in the electrolyte that require reduction treatment, such as reducible organic matter and nitrogen oxides in the landfill leachate.

[0163] Example 2

[0164] The gas-liquid mixing electrochemical reaction device shown in Figure 2 is Example 2 of the present invention, which is also a type A gas-liquid mixing electrochemical reaction device. Unlike the device in Figure 1, the anode tank area and the cathode tank area are both covered by a sealed tank cover 28 for collecting the escaped gas from the electrolytic cell reaction, and its electrocatalytic components use two components of the electrocatalytic method (⑴) in both tank areas, that is, several bipolar electrodes 6, insoluble anode conductors 23 and insoluble cathode conductors 24 are set in both tank areas, and they are all immersed in the electrolyte; an electrolytic cell gas-liquid mixer 7 is provided in the anode tank area and the cathode tank area, which adopts a vacuum jet electrolytic cell gas-liquid mixer, and the outlet of each electrolytic cell gas-liquid mixer 7 extends above the electrolyte surface of the corresponding tank area and forks towards the bipolar electrode 6 and the electrolysis electrode respectively.

[0165] Example 3

[0166] The gas-liquid mixing electrochemical reaction device shown in Figure 3 is Example 3 of the present invention, which is a Type B device. Unlike the Type A device shown in Figure 1, the anode tank area and the cathode tank area are both covered by a sealed tank cover 28 for collecting the escaped gas from the electrolytic cell reaction. In addition to adopting bipolar electrolysis 6, the electrocatalytic component arranged in the electrolytic cell area where the electrolytic cell gas-liquid mixer outlet is located also adopts an electrolytic anode or electrolytic cathode in the form of a parallel electrode. The air inlet of the vacuum jet electrolytic cell gas-liquid mixer 7 adopts not only the self-generated gas connected to the cathode tank area, but also external input gas.

[0167] Example 4

[0168] The gas-liquid hybrid electrochemical reaction device shown in FIG4 is Example 4 of the present invention. It is a C-2 type gas-liquid hybrid electrolytic cell, comprising an electrolytic cell body 1, a cell divider, a sealed cell cover 28 for collecting escaping gas from the cell reaction, an insulating through-hole support baffle 12, an electrolytic anode 3 and an electrolytic cathode 4, an electrolytic power supply 5, an electrocatalytic component, and an electrolytic cell gas-liquid mixer. Depending on the requirements of the oxidation or reduction reaction, the positions of the electrolytic anode 3 and the electrolytic cathode 4 can be interchanged. Thus, electrolytic electrode 90-1 can serve as either the electrolytic anode or the electrolytic cathode, while electrolytic electrode 90-2 serves as the corresponding other electrode. The electrolytic cell separator adopts electrolytic cell separator 2#83, which divides the electrolytic cell body 1 into an anode cell area and a cathode cell area; one of the insulating through-hole support baffles 12 12-1 separates the electrolytic anode 3 and the outlet of the electrolytic cell gas-liquid mixer, and the second insulating through-hole support baffle 12 12-2 overlaps with the electrolytic cell separator 2 to separate the electrolytic anode and the electrolytic cathode. The sealed tank cover 28 for collecting the escaped gas of the electrolytic cell reaction covers the electrolytic cell body 1; when the electrolytic electrode 90-1 is the electrolytic anode, an electrocatalytic component, i.e., an insoluble anode conductor 23, is set in the anode cell area and immersed in the electrolyte in the anode cell area, and the electrolytic cathode 4 is a parallel electrode connected in parallel; when the electrolytic electrode 90-1 is the electrolytic cathode, an electrocatalytic component, i.e., an insoluble anode conductor 23, is set in the cathode cell area. The cathode conductor 24 is immersed in the electrolyte in the cathode tank area, and the electrolytic anode 3 is a parallel electrode connected in parallel; the electrolyte in the anode tank area and the electrolyte in the cathode tank area are respectively leachate; the electrolytic cell gas-liquid mixer adopts an electrolytic cell gas-liquid mixer 9 that combines vacuum jet and bubbling types, which has an air inlet, a liquid inlet and an outlet, and the liquid inlet is connected to the electrolytic cell body. That is, this embodiment uses external input gas from outside the electrolytic cell to mix the electrolyte in the anode tank area or the electrolyte in the cathode tank area, and sprays it through the outlet extending to the bottom of the electrolyte surface in the anode tank area and toward the electrocatalytic component, that is, the insoluble anode conductor 23, or extends to the bottom of the electrolyte surface in the cathode tank area and toward the electrocatalytic component, that is, the insoluble cathode conductor 24.

[0169] Example 5

[0170] The gas-liquid hybrid electrochemical reaction device shown in Figure 5 is Example 5 of the present invention and is a C-1 type gas-liquid hybrid electrolytic cell. It comprises an electrolytic cell body 1, one of the electrolytic cell separators 2-1 and two of the electrolytic cell separators 2-2, an electrolytic anode 3, an electrolytic cathode 4, an electrolytic power supply 5, an electrocatalytic component, an electrolytic cell gas-liquid mixer, and an electrically insulating mesh box 11 for securing the bipolar electrode stack. The electrolytic anode 3 is connected to the positive electrode of the electrolytic power supply 5, and the electrolytic cathode 4 is connected to the negative electrode of the electrolytic power supply 5. The electrolytic cell body 1 is provided with electrolytic cell separators 2-1 and 2-2, dividing it into an electrolytic anode cell area, an intermediate cell area, and an electrolytic cathode cell area. A bipolar electrode stack fixed electrically insulating mesh box 11 is provided in the intermediate cell area and loaded with an electrocatalytic component, namely a plurality of bipolar electrodes 6. The electrolytic cell separator 2-1 is an anion exchange membrane, and the electrolytic cell separator 2-2 is a reverse osmosis membrane. A bubble drainage cover 95 is provided at the electrolytic anode. A sealed tank cover 28 for collecting escaping gases from the electrolytic cell reaction only covers the electrolytic anode cell area and the intermediate cell area. The portion of the sealed tank cover 28 located in the anode cell area is provided with an oxidizing gas discharge pipe port 30, and the portion of the sealed tank cover 28 located in the intermediate cell area is provided with a gas-liquid mixed electrolytic cell exhaust pipe port 51. A gas pressure equalization connecting pipe 56 is provided between the electrolytic anode cell area and the intermediate cell area. The electrolyte in the intermediate cell area is the reaction liquid to be treated. The electrolytic cell gas-liquid mixer adopts a vacuum jet electrolytic cell gas-liquid mixer 7, which has an air inlet, a liquid inlet and an outlet. The air inlet is provided with an air inlet branch pipe, and the liquid inlet is connected to the middle tank area. That is, this embodiment simultaneously uses external input gas from outside the electrolytic cell and electrolysis gas generated in the anode tank area to mix gas and liquid with the electrolyte in the middle tank area, and sprays it through an outlet extending above the electrolyte surface in the middle tank area and toward the electrocatalytic component, i.e., the bipolar electrode.

[0171] Example 6

[0172] The gas-liquid hybrid electrochemical reactor shown in Figure 6 is Example 6 of the present invention, and is a C-1 type gas-liquid hybrid electrochemical reactor. It comprises an electrolytic cell body 1, one of the electrolytic cell dividers 2-1 and two of the electrolytic cell dividers 2-2, an electrolytic anode 3, an electrolytic cathode 4, an electrolytic power supply 5, a catalytic component, an electrolytic cell gas-liquid mixer, a gas-liquid separation and washing tank 13, and a bubble-containing reaction liquid deflector 93. The electrolytic anode 3 is connected to the positive electrode of the electrolytic power supply 5, and the electrolytic cathode 4 is connected to the negative electrode of the electrolytic power supply 5. The electrolytic cell body 1 is provided with electrolytic cell separators 2-1 and 2-2 to divide it into an electrolytic anode cell area, an intermediate cell area and an electrolytic cathode cell area, and an electrocatalytic component, namely a plurality of bipolar electrodes 6, is provided in the intermediate cell area; the electrolytic cell separator 2-3 is an anion exchange membrane, the electrolytic cell separator 2-4 is a reverse osmosis membrane, and a bubble-containing reaction liquid flow guide 93 is provided at the electrolytic cathode; the bubble-containing reaction liquid flow guide 93 is connected to the cathode cell area through a gas-liquid separation washing tank 13, and the sealed tank cover 28 for collecting the escaped gas from the electrolytic cell reaction only covers the intermediate cell area and the electrolytic cathode cell area, and the part located in the intermediate cell area is provided with a gas-liquid mixed electrolytic cell exhaust pipe port 51, and a gas pressure balance connecting pipe 56 is provided between the electrolytic cathode cell area and the intermediate cell area; the electrolyte in the intermediate cell area is the reaction liquid that needs to be treated. The electrolytic cell gas-liquid mixer adopts a vacuum jet electrolytic cell gas-liquid mixer 7, which has an air inlet, a liquid inlet and an outlet. The air inlet is connected to the air outlet of the gas-liquid separation washing tank 13, and the liquid inlet is connected to the middle tank area. That is, this embodiment uses the electrolysis gas generated in the cathode tank area and the electrolyte in the middle tank area to mix the gas and liquid, and sprays it through the outlet extending above the electrolyte surface in the middle tank area and toward the electrocatalytic component, i.e., the bipolar electrode.

[0173] Example 7

[0174] The gas-liquid hybrid electrochemical reaction device shown in Figure 7 is Example 7 of the present invention, and is a C-2 type gas-liquid hybrid electrolytic cell. It comprises an electrolytic cell body 1, an electrolytic anode 3, an electrolytic cathode 4, an electrolytic power supply 5, an electrocatalytic component, an electrolytic cell gas-liquid mixer, and an insulating through-hole support baffle 12. Depending on the requirements of the oxidation or reduction reaction, the positions of the electrolytic anode 3 and the electrolytic cathode 4 can be interchanged. Thus, electrolytic electrode 90-1 serves as either the electrolytic anode or the electrolytic cathode, while electrolytic electrode 90-2 serves as the corresponding other electrode. The electrolytic anode 3 is connected to the positive electrode of the electrolytic power supply 5, and the electrolytic cathode 4 is connected to the negative electrode of the electrolytic power supply 5. An electrocatalytic component, namely an insoluble anode conductor 23 and an insoluble cathode conductor 24, is provided in the electrolytic cell body 1. When the electrolytic electrode 90-1 is the electrolytic anode, the conductor 63-1 is the insoluble anode conductor 23 and the conductor 63-2 is the insoluble cathode conductor 24. When the electrolytic electrode 90-1 is the electrolytic cathode, the opposite is true. A sealed tank cover 28 for collecting the escaped gas from the electrolytic cell reaction is covered on the electrolytic cell body. The electrolytic cell gas-liquid mixer adopts a vacuum jet type and bubbling type combined electrolytic cell gas-liquid mixer 9, which is electrically connected to the electrolytic power supply and has a jet tube. An ultrasonic generator 25 is installed, which has an air inlet, a liquid inlet and an outlet. The liquid inlet is connected to the electrolytic cell body. That is, in this embodiment, external input gas from outside the electrolytic cell is mixed with the electrolyte in the electrolytic cell body to mix gas and liquid, and is ejected through an outlet extending below the electrolytic anode 3 and the electrocatalytic component, i.e., the insoluble anode conductor 23, or through an outlet extending below the electrolytic cathode 4 and the electrocatalytic component, i.e., the insoluble cathode conductor 24; an insulating through-hole support baffle 12 is arranged between the electrolytic anode 3 or the electrolytic cathode 4 and the outlet of the electrolytic cell gas-liquid mixer.

[0175] Example 8

[0176] The gas-liquid hybrid electrochemical reaction device shown in Figure 8 is Example 8 of the present invention. It is a three-divided gas-liquid hybrid electrolytic cell formed by symmetrically combining the A-type cell of Figure 1. It comprises an electrolytic cell body 1, an electrolytic cell divider 2, an electrolytic anode 3, an electrolytic cathode 4, an electrolytic power supply 5, an electrocatalytic component, and an electrolytic cell gas-liquid mixer. Depending on the requirements of the oxidation or reduction reaction, the positions of the electrolytic anode 3 and the electrolytic cathode 4 can be interchanged. Therefore, electrolytic electrodes 90-1 and 90-3 serve as either the electrolytic anode or the electrolytic cathode, while electrolytic electrode 90-2 serves as the corresponding alternative electrode. The electrolytic anode 3 is connected to the positive electrode of the electrolytic power supply 5, and the electrolytic cathode 4 is connected to the negative electrode of the electrolytic power supply 5. The electrolytic cell body 1 is provided with one of the electrolytic cell separators 2-1 and the other 2-2, which divide it into two electrolytic anode cell areas and one electrolytic cathode cell area, or one electrolytic anode cell area and one electrolytic cathode cell area; when the electrolytic electrodes 90-1 and 90-3 are electrolytic anodes, the two anode cell areas are respectively provided with an electrocatalytic component bipolar electrode 6-1 and an insoluble anode conductor 23-1 directly conductively connected to the electrolytic anode, a bipolar electrode 6-2 and an insoluble anode conductor 23-2; or when the electrolytic electrodes 90-1 and 90-3 are electrolytic cathodes, the two cathode cell areas are respectively provided with an electrocatalytic component bipolar electrode 6-1 and an insoluble anode conductor 24-1 directly conductively connected to the electrolytic cathode, a bipolar electrode 6-2 and an insoluble cathode conductor 24-2; the escaped gas from the electrolytic cell reaction is collected The sealing tank covers 28-1 and 28-2 cover the two electrolytic anode tank areas or the two electrolytic cathode tank areas respectively; the electrolytic tank gas-liquid mixer adopts a vacuum jet electrolytic tank gas-liquid mixer 7-1 and 7-2, which has an air inlet, a liquid inlet and an outlet. The air inlet is connected to the air outlet of the sealing tank covers 28-1 and 28-2 respectively, and the liquid inlet is connected to the two electrolytic anode tank areas or the two electrolytic cathode tank areas respectively. That is, in this embodiment, the electrolysis gas generated in the anode tank area is mixed with the electrolyte in the anode tank area for gas-liquid mixing and is ejected through the outlet extending above the electrolyte surface of the electrolytic anode tank area and toward the electrocatalytic component, i.e., the bipolar electrode, or the electrolysis gas generated in the cathode tank area is mixed with the electrolyte in the cathode tank area for gas-liquid mixing and is ejected through the outlet extending above the electrolyte surface of the electrolytic cathode tank area and toward the electrocatalytic component, i.e., the bipolar electrode.

[0177] Example 9

[0178] The gas-liquid hybrid electrochemical reaction device shown in Figure 9 is Example 9 of the present invention. It is a three-divided-tank gas-liquid hybrid electrolytic cell constructed by symmetrically combining the C-2-type cells of Figure 4. It comprises an electrolytic cell body 1, electrolytic cell dividers, a sealed tank cover 28 for collecting escaping gas from the electrolytic cell reaction, an insulating through-hole support baffle 12, an electrolytic anode 3 and an electrolytic cathode 4, an electrolytic power supply 5, an electrocatalytic component, and an electrolytic cell gas-liquid mixer. Depending on the requirements of the oxidation or reduction reaction, the positions of the electrolytic anode 3 and the electrolytic cathode 4 can be interchanged. Therefore, electrolytic electrodes 90-1 and 90-3 serve as either the electrolytic anode or the electrolytic cathode, while electrolytic electrode 90-2 serves as the corresponding other electrode. The electrolytic cell separators are electrolytic cell separators 2#83, one 83-1 and two 83-2, which are respectively superimposed on insulating through-hole support baffles 12#12-2 and three 12-3 to separate the electrolytic cell body 1 into an anode cell area and a cathode cell area. The insulating through-hole support baffles 12#12-1 and four 12-4 separate the electrolytic electrodes 90-1 and 90-3 and the outlet of the electrolytic cell gas-liquid mixer in two identical cell areas. The sealed tank covers 28#28-1, two 28-2 and three 28-3 for collecting the escaped gas from the electrolytic cell reaction are respectively covered on each cell area of ​​the electrolytic cell body 1. When the electrolytic electrode 90-1 is an electrolytic anode, an electrocatalytic component, i.e., an insoluble anode conductor 23, is provided in the anode cell area and immersed in the electrolyte in the anode cell area. The electrolytic cathode 4 is a parallel electrode connected in parallel. When the electrolytic electrode 90-1 is an electrolytic cathode, the electrolytic cathode 4 is a parallel electrode connected in parallel. During the electrolysis, an electrocatalytic component, i.e., an insoluble cathode conductor 24, is arranged in the cathode tank area and immersed in the electrolyte in the cathode tank area. The electrolytic anode 3 is a parallel electrode connected in parallel; the electrolyte in the anode tank area and the electrolyte in the cathode tank area are respectively the reaction liquids to be treated; the electrolytic tank gas-liquid mixer adopts one 9-1 and the other 9-2 of the electrolytic tank gas-liquid mixers which are a combination of vacuum jet type and bubbling type, which have an air inlet, a liquid inlet and an outlet, and the liquid inlet is connected to the electrolytic tank body, that is, this embodiment uses external input gas from outside the electrolytic tank to mix gas and liquid with the electrolyte in the anode tank area or the electrolyte in the cathode tank area, and sprays it through the outlet extending to the bottom of the electrolyte surface of the anode tank area and toward the electrocatalytic component, i.e., the insoluble cathode conductor 23, or extends to the bottom of the electrolyte surface of the cathode tank area and toward the outlet of the electrocatalytic component, i.e., the insoluble cathode conductor 24.

[0179] Example 10

[0180] The gas-liquid mixing electrochemical reaction device shown in Figure 10 is Example 10 of the present invention. It is a C-2 type cell with a circular electrode distribution structure. It consists of an electrolytic cell body 1, a sealed tank cover 28 for collecting escaping gases from the electrolytic cell reaction, a gas-liquid separation and washing tank 13, an electrolytic anode 3 and an electrolytic cathode 4, an electrolytic power supply 5, an electrocatalytic component, an electrolytic cell gas-liquid mixer, and temporary storage tanks 20-1 and 20-2. Depending on the requirements of the oxidation or reduction reaction, the positions of the electrolytic anode 3 and the electrolytic cathode 4 can be interchanged. Electrolytic electrode 90-1 serves as either the electrolytic anode or cathode, and electrolytic electrode 90-2 serves as the corresponding electrode. Electrolytic electrode 90-2 is the central electrode connected to one of the eight electrolytic power supplies 5, 5-1 to 5-8. Electrolytic electrode 90-1 is a plurality of electrodes arranged around the central electrode and connected to the other electrode of each electrolytic power supply. Multiple electrolysis electrodes 90-1 are separated by insulating partitions, and there is no separation between the electrolysis electrode 90-1 and the electrolysis electrode 90-2. At the same time, the electrolysis anode and the electrolysis cathode are improved in electrocatalytic performance structure: the electrolysis electrode 90-1 and the electrolysis electrode 90-2 are both connected in parallel and the angle formed by the local part of the electrolysis electrode with the gas-liquid mixture ejection straight line of the electrolysis tank gas-liquid mixer is greater than 0° and less than 90°, and an electrocatalytic component is provided, namely an insoluble anode conductor 23 or an insoluble cathode conductor 24 in contact with the electrolysis electrode 90-2; a sealed seal is provided for collecting the escaped gas from the electrolysis tank reaction. The tank cover 28 covers the electrolytic cell body 1, and its gas-liquid mixing electrolytic cell exhaust pipe port 51 is connected to the temporary storage tank 20-1 and the temporary storage tank 20-2 respectively through the gas-liquid separation washing tank 13; the electrolytic cell gas-liquid mixer is a vacuum jet type and bubbling type combined electrolytic cell gas-liquid mixer 9, which has an air inlet, a liquid inlet and an outlet. The liquid inlet is connected to the temporary storage tank 20-1 and the temporary storage tank 20-2. That is, in this embodiment, external input gas from outside the electrolytic cell is used to mix with the electrolyte in the electrolytic cell body 1, and the gas and liquid are ejected through the outlet extending to the bottom of the electrolyte surface and toward the electrolysis electrode 90-1.

[0181] Example 11

[0182] The gas-liquid mixing electrochemical reaction device shown in Figure 11 is Example 11 of the present invention. It features an A-type cell with a circular electrode distribution structure. It comprises an electrolytic cell body 1, a cell divider 2, an insulating through-hole support baffle 12, an overflow buffer tank 22, a sealed tank cover 28 for collecting escaping gas from the electrolytic cell reaction, an electrolytic anode 3 and an electrolytic cathode 4, an electrolytic power supply 5, an electrocatalytic component, an electrolytic cell gas-liquid mixer, and an electrolyte ion current interrupter 89. Depending on the requirements of the oxidation or reduction reaction, the positions of the electrolytic anode 3 and electrolytic cathode 4 can be interchanged, with 90-1 representing either the electrolytic anode or cathode, and electrolytic electrode 90-2 representing the corresponding other electrode. An electrolytic cell separator 2 is provided in the electrolytic cell body 1 to separate it into an electrolytic anode cell area and an electrolytic cathode cell area, and an insulating through-hole support baffle 12 is provided below the electrolytic electrode. The electrolytic cell separator 2 is an anion exchange membrane, and an electrocatalytic component, namely a bipolar electrode 6, is provided in the cell area where the electrolytic electrode 90-1 is located. The electrolytic electrode 90-2 is the central electrode connected to one pole of the eight electrolytic power sources 5 5-1 to 5-8. The electrolytic electrode 90-1 is a plurality of electrodes arranged around the central electrode and is respectively connected to the other pole of each electrolytic power source. The sealed tank cover 28 for collecting the escaped gas from the electrolytic cell reaction covers the electrolytic cell body 1, and the tank area where the electrolytic electrode 90-1 is located is connected to the electrolyte ion current interrupter 89 and the overflow buffer tank 22 through a pipeline; the electrolytic cell gas-liquid mixer is a vacuum jet type and bubbling type combined electrolytic cell gas-liquid mixer 9, which has an air inlet, a liquid inlet and an outlet. The liquid inlet is connected to the overflow buffer tank 22, and the air inlet is connected to the tank area where the electrolytic electrode 90-1 is located. That is, in this embodiment, the gas electrolyzed in the tank area where the electrolytic electrode 90-1 is located is mixed with the electrolyte in the tank area where the electrolytic electrode 90-1 is located, and the gas is ejected through the outlet extending to the bottom of the electrolyte surface and toward the electrolytic electrode 90-1.

[0183] Example 12

[0184] As shown in Figure 17, this is Example 12 of a method for treating landfill leachate using a gas-liquid hybrid electrochemical reaction device according to the present invention. The device is a separate gas-liquid hybrid electrolytic cell.

[0185] The gas-liquid mixing electrolytic cell is a Type A cell of the structure shown in Figure 2, comprising an electrolytic cell body 1, an electrolytic cell divider 2, an electrolytic anode 3, an electrolytic cathode 4, an electrolytic power supply 5, and two vacuum jet electrolytic cell gas-liquid mixers 7-1 and 7-2. The electrolytic anode 3 is connected to the positive electrode of the electrolytic power supply 5, and the electrolytic cathode 4 is connected to the negative electrode of the electrolytic power supply 5. The electrolytic cell body 1 is provided with an electrolytic cell divider 2, dividing it into an electrolytic anode cell area and an electrolytic cathode cell area, wherein electrocatalytic components, namely bipolar electrodes 6-1 and 6-2, are respectively disposed. The electrolytic cell gas-liquid mixer 7-1 is connected to the electrolytic cell body anode cell area via a pump 53-1 via a liquid flow conduit, with its outlet directed toward the electrolytic anode 3 and bipolar electrode 6-1. The electrolytic cell gas-liquid mixer 7-2 is connected to the electrolytic cell body cathode cell area via a pump 53-2 via a liquid flow conduit, with its outlet directed toward the electrolytic cathode 4 and bipolar electrode 6-2. The electrolytic cell body 1 is also provided with sealing tank covers 28-1 and 28-2, which are also provided with tail gas outlets respectively. The gas outlet of the electrolytic anode tank area is connected to the gas inlet of the electrolytic cell gas-liquid mixer 7-1, and the gas outlet of the electrolytic cathode tank area is connected to the gas inlet of the electrolytic cell gas-liquid mixer 7-2.

[0186] The electrolytic cell separator 2 is the electrolytic cell separator 1 # , specifically a bipolar membrane. The electrolysis anode 3 is platinum metal. The electrolysis cathode 4 is stainless steel, and the conductor in the bipolar electrode 6 is platinum metal.

[0187] Landfill leachate was used as the anolyte and catholyte, respectively, with a pH of 6.5. The anode and cathode volumes of the electrolytic cell were 25 liters and 25 liters, respectively, for a total wastewater treatment capacity of 50 liters.

[0188] The purpose of this experiment is to use a gas-liquid mixed electrochemical reaction device to react and treat nitrogen pollutants in landfill leachate, mainly eliminating NH3 through electrochemical oxidation and NO2 through electrochemical reduction. - and N03 - The specific working principle is as follows:

[0189] In the anode tank, the electrolytic anode 3 and the anode end of the bipolar electrode 6-1 undergo an electrochemical reaction in which organic pollutants are oxidized to chlorine gas and oxygen is released from water. At the cathode end of the bipolar electrode 6-1, organic pollutants are reduced to hydrogen gas through electrolysis or hydrogen ion reduction. Simultaneously, the chlorine generated in the anolyte dissolves in the electrolyte to form hypochlorite, which reacts with NH3 to remove ammonia nitrogen in the following reaction: 2NH3 + 3ClO - →3Cl - +3H2O+N2↑

[0190] In the cathode tank area, the end of the bipolar electrode 6-2 that acts as the anode undergoes electrochemical reactions in which chloride ions are oxidized to chlorine gas and water is electrolyzed to release oxygen; the electrolytic cathode 4 and the end of the bipolar electrode 6-2 that acts as the cathode undergo electrochemical reactions in which organic pollutants are reduced, water is electrolyzed or hydrogen ions are reduced to release hydrogen gas, and the chlorine gas produced in the cathode electrolyte is reduced to chloride ions, as well as the following NO2 - and N03 - The electrochemical reaction of reduction: HNO2+H + +e - →H2O+NO↑ 2HNO2+6H + +6e - →4H2O+N2↑ HNO2+6H + +6e - →2H2O+NH3 HNO3+3H + +3e - →2H2O+NO↑ 2HNO3+10H + +10e - →6H2O+N2↑ HNO3+8H + +8e - →3H2O+NH3

[0191] The process steps of the method for treating landfill leachate using a gas-liquid mixed electrochemical reaction device in this embodiment are as follows:

[0192] 1. The landfill leachate is used as the treated liquid and is respectively fed into the anode tank area and cathode tank area of ​​the gas-liquid mixed electrolytic cell.

[0193] 2. Start pumps 53-1 and 53-2, turn on the electrolysis power supply, and adjust the cell voltage to 360V and the electrolysis current to 6A to conduct a redox reaction for 5 hours, causing chlorine and oxygen to be electrolyzed at the electrolysis anode and hydrogen to be electrolyzed at the electrolysis cathode. The chlorine and oxygen react with organic pollutants and NH3 in the anolyte. The Cl2 and O2 escaping the liquid surface are mixed by ejector 7-1 as a gas-liquid mixture and sprayed toward the bipolar electrode 6-1 and the electrolysis anode for an electrochemical oxidation reaction. Simultaneously, the hydrogen escaping the liquid surface is mixed by ejector 7-2 as a gas-liquid mixture with the cathode electrolyte and sprayed toward the bipolar electrode 6-2 and the electrolysis cathode for an electrochemical reduction reaction in the electrocatalytic process. The anolyte mainly reacts with NH3 and Cl2 to produce nitrogen for ammonia removal treatment, while the cathode electrolyte mainly reacts with nitrate nitrogen and H + The reaction generates NO, N2, and NH3 to remove nitrate nitrogen (NO2 - and N03 - )reaction.

[0194] After the redox reaction, the anolyte was extracted to measure the NH3 concentration, and the catholyte was extracted to measure the combined concentration of organic amines and nitrate nitrogen. The data before and after treatment were compared to obtain the treatment results. The treatment data and test results are listed in Table 1.

[0195] Example 13

[0196] FIG18 shows Example 13 of a method for treating landfill leachate using a gas-liquid hybrid electrochemical reaction device according to the present invention. The device comprises a gas-liquid hybrid electrolytic cell, two conventional vacuum jet gas-liquid mixers 15, a gas-liquid separation and washing tank 13, a chemical reaction tank 21, a buffer tank 22, a gas pressure pump 55, a refrigerator 70, an ozone generator 97, and a pump.

[0197] The gas-liquid mixing electrolytic cell is an A-type cell of the structure shown in Figure 1, comprising an electrolytic cell body 1, an electrolytic cell divider 2, an electrolytic anode 3, an electrolytic cathode 4, an electrolytic power supply 5, and a combined vacuum jet and bubbling electrolytic cell gas-liquid mixer 9. The electrolytic anode 3 is connected to the positive electrode of the electrolytic power supply 5, and the electrolytic cathode 4 is connected to the negative electrode of the electrolytic power supply 5. The electrolytic cell body 1 is provided with an electrolytic cell divider 2, dividing it into an electrolytic anode cell area and an electrolytic cathode cell area, each of which contains electrocatalytic components. The anode cell area is provided with an insoluble anode conductor 23, which is directly electrically connected to the electrolytic anode. The cathode cell area is provided with a bipolar electrode 6 and an insoluble cathode conductor 24, which is directly electrically connected to the electrolytic cathode. The electrolytic cell gas-liquid mixer 9 is connected to the electrolytic cell body cathode cell area via a buffer tank 22-2 and a pump 53-3 via a liquid flow conduit, with its outlet directed toward the electrolytic cathode 4, the insoluble cathode conductor 24, and the bipolar electrode 6. The electrolytic cell body 1 is further provided with sealing slot covers 28 - 1 and 28 - 2 , each of which is provided with an exhaust gas outlet. The gas outlet of the electrolytic cathode cell area is connected to the gas inlet of the electrolytic cell gas-liquid mixer 9 .

[0198] The electrolytic cell separator 2 is the electrolytic cell separator 1 # , specifically a reverse osmosis membrane. The electrolysis anode is a titanium-based insoluble anode, the electrolysis cathode is stainless steel, and the bipolar electrode is platinum.

[0199] The tail gas outlet of the electrolytic anode tank is connected to the gas inlet of a conventional vacuum jet gas-liquid mixer 15-2. The outlet of conventional vacuum jet gas-liquid mixer 15-2 is located in gas-liquid separation and washing tank 13. The liquid outlet of gas-liquid separation and washing tank 13 is connected to the liquid inlet of conventional vacuum jet gas-liquid mixer 15-2 via pump 53-2. The tail gas outlet of gas-liquid separation and washing tank 13 is connected to the gas inlet of another conventional vacuum jet gas-liquid mixer 15-1 via a gas booster pump 55, a refrigerator 70, and an ozone generator 97. The outlet of conventional vacuum jet gas-liquid mixer 15-1 is located in chemical reaction tank 21. The liquid outlet of chemical reaction tank 21 is connected to the liquid inlet of conventional vacuum jet gas-liquid mixer 15-1 via a buffer tank 22-1 and pump 53-1.

[0200] The chemical reaction tank 21 contains pre-treated landfill leachate 44-1, specifically a solution adjusted to a pH of >14 by adding sodium hydroxide. The processing capacity of the chemical reaction tank 21 is 25 liters. The gas-liquid hybrid electrochemical device has an anolyte of sodium hydroxide at a pH of 12 and a catholyte of pre-treated landfill leachate 44-2, specifically a solution adjusted to a pH of 9 by adding potassium hydroxide.

[0201] The purpose of this experiment is to use a gas-liquid mixed electrolytic cell in which the cathode tank area performs a reduction reaction of organic pollutants on the pre-treated landfill leachate 44-2 and removes nitrate nitrogen (NO2 - 、NO3 - ) electrochemical reaction, and at the same time, the oxygen electrolyzed in the anode tank area is transported to the ozone generator 97 to produce ozone, so that the produced ozone is used in another chemical reaction tank to remove NH3 from the pre-treated landfill leachate 44-1.

[0202] The ozone produced by the ozone generator 97 is input into the chemical reaction tank 21 to react with the organic waste liquid 44-1 for oxidation, as well as the following NH3 removal reaction and other chemical reactions: 6NH3+7O3→9H2O+6NO2Cl - +O3→ClO - +O2↑ 2NH3+3ClO - →3Cl - +3H2O+N2 H2O+3NO2→2HNO3+NO↑

[0203] The process steps of the method for treating landfill leachate using a gas-liquid mixing electrochemical reaction device in this embodiment are as follows:

[0204] 1. Potassium hydroxide is added to the landfill leachate to adjust the pH to 9 to obtain pre-treated landfill leachate 44-2, which is then fed into the cathode tank section and buffer tank 22-2 of a gas-liquid mixing electrochemical reaction device. A sodium hydroxide solution with a pH of 12 is fed into the anode tank section of the gas-liquid mixing electrochemical reaction device. In addition, sodium hydroxide is added to the landfill leachate to adjust the pH to greater than pH 14 to obtain pre-treated landfill leachate 44-1, which is then fed into the chemical reaction tank 21 and buffer tank 22-1.

[0205] 2. Start pumps 53-1, 53-2, and 53-3, as well as gas booster pump 55, refrigerator 70, and ozone generator 97. Turn on the electrolysis power supply to cause oxygen to be deposited at the anode and hydrogen to be deposited at the cathode. The deposited oxygen is then directed to washing tank 13 for washing. The oxygen that escapes the washing water is then taken to the refrigerator for freeze-dehydration and then used by the ozone generator. A chemical reaction is performed on pre-treated landfill leachate 44-2 using a gas-liquid mixing electrochemical reaction device for 10 hours. Simultaneously, a chemical reaction is performed on pre-treated landfill leachate 44-1 using chemical reaction tank 21 for 10 hours.

[0206] The reaction liquid was sampled for nitrogen-containing pollutants testing, and the results before and after treatment were compared. The treatment data and test results are listed in Table 1.

[0207] Example 14

[0208] FIG19 shows Example 14 of a method for treating landfill leachate using a gas-liquid hybrid electrochemical reaction device according to the present invention. The device comprises three gas-liquid hybrid electrolytic cells, a temporary storage tank 20, three chemical reaction tanks 21, two buffer tanks 22, a solid-liquid separator 26, three polluted tail gas treatment tanks 27, a conventional electrolytic cell 57, a sensor 66, a safety photoelectric control alarm system 77, a chlorine gas cylinder 80, valves, and a pump.

[0209] One of the gas-liquid hybrid electrolytic cells is a Type B cell, shown in FIG3 , used for electrochemical oxidation reactions. It includes an electrolytic cell body 1-1, an electrolytic cell separator 2-1, an electrolytic anode 3-1, an electrolytic cathode 4-1, an electrolytic power supply 5-1, and a vacuum jet electrolytic cell gas-liquid mixer 7-1. The electrolytic anode 3-1 is connected to the positive electrode of the electrolytic power supply 5-1, and the electrolytic cathode 4-1 is connected to the negative electrode of the electrolytic power supply 5-1. An electrolytic cell body 1-1 is provided with an electrolytic cell separator 2-1 to separate it into an electrolytic anode cell area and an electrolytic cathode cell area. A bipolar electrode 6-1 and an insoluble anode conductor 23-1 directly conductively connected to the electrolytic anode are provided in the anode cell area. A vacuum jet electrolytic cell gas-liquid mixer 7-1 is connected to the anode cell area of ​​the electrolytic cell body via a pump 53-6 by a liquid flow conduit, and its outlet faces the electrolytic anode 3-1, the insoluble anode conductor 23-1, and the bipolar electrode 6-1. The electrolytic cell separator 2-1 is an anion exchange membrane.

[0210] The second gas-liquid hybrid electrolytic cell is a C-2 type cell of the structure shown in FIG7 , which is used for electrochemical reduction reactions. It includes an electrolytic cell body 1-2, an electrolytic anode 3-3, an electrolytic cathode 4-3, an electrolytic power supply 5-3, and a vacuum jet and bubbling electrolytic cell gas-liquid mixer 9. The electrolytic anode 3-3 is connected to the positive electrode of the electrolytic power supply 5-3, and the electrolytic cathode 4-3 is connected to the negative electrode of the electrolytic power supply 5-3. The electrolytic cell body 1-2 is provided with an insoluble anode conductor 23-2 that is directly conductively connected to the electrolytic anode and an insoluble cathode conductor 24 that is directly conductively connected to the electrolytic cathode. The electrolytic cell gas-liquid mixer 9, which combines vacuum jet and bubbling types, is connected to the electrolytic cell body 1-2 as a liquid flow pipeline via a pump 53-10. The insoluble anode conductor is made of titanium and an ultrasonic generator 25 is installed on its jet tube, whose outlet is directed toward the electrolytic anode 3-3 and the insoluble anode conductor 23-2.

[0211] The third gas-liquid hybrid electrolytic cell is a C-1 type cell of the structure shown in Figure 5 , used for electrochemical oxidation reactions. It includes an electrolytic cell body 1-3, electrolytic cell separators 2-3 and 2-4, an electrolytic anode 3-4, an electrolytic cathode 4-4, an electrolytic power supply 5-4, and a vacuum jet electrolytic cell gas-liquid mixer 7-2. The electrolytic anode 3-4 is connected to the positive electrode of the electrolytic power supply 5-4, and the electrolytic cathode 4-4 is connected to the negative electrode of the electrolytic power supply 5-4. Electrolytic cell body 1-3 is provided with electrolytic cell dividers 2-3 and 2-4 to divide it into an electrolytic anode cell area, an intermediate cell area, and an electrolytic cathode cell area, and a bipolar electrode 6-2 is provided in the intermediate cell area. A vacuum jet electrolytic cell gas-liquid mixer 7-2 is connected to the intermediate cell area of ​​the electrolytic cell body via a pump 53-14 as a liquid flow conduit, and its outlet faces the bipolar electrode 6-2. Electrolytic cell divider 2-3 is an anion exchange membrane, and electrolytic cell divider 2-4 is a reverse osmosis membrane. A bubble drainage hood 95 in the electrolyte is provided at the electrolytic anode.

[0212] The anolyte of the first gas-liquid hybrid electrolytic cell is organic waste liquid 44-2, and the catholyte 48-1 is sodium hydroxide solution. The electrolyte of the second gas-liquid hybrid electrolytic cell is solution 44-4. The anolyte and catholyte of the third gas-liquid hybrid electrolytic cell are both sodium chloride solution.

[0213] The alkaline solution 49 is a sodium hydroxide solution, and the acidic solution is hydrochloric acid.

[0214] The ferrous salt solution 72 is a ferrous chloride solution.

[0215] The polluted tail gas treatment tank 27-1 uses sodium hydroxide solution to absorb acidic tail gas for environmental protection. The polluted tail gas treatment tank 27-2 uses ferrous chloride solution 72 to absorb Cl2. The polluted tail gas treatment tank 27-3 uses water to separate NH3, NO, and H2. After the reaction, ammonium nitrate solution is generated. The separated hydrogen tail gas is safely discharged to high altitude.

[0216] The chemical reaction tank 21-1 is used to remove NH3 from alkaline landfill leachate 44-1 using chlorine. Chemical reaction tank 21-2 adds acid to organic waste liquid 44-2 to adjust its pH to pH 3 for an acidic oxidation reaction. Chemical reaction tank 21-3 is used to remove chlorine from organic waste liquid 44-6 and perform a neutralization reaction.

[0217] The conventional electrolytic cell 57 is used to produce Cl2 and H2 as raw materials for the operation of the device. The electrolytic cell separator 2-2 is a cation exchange membrane, the anolyte is 99% sodium chloride, and the catholyte is 49% sodium hydroxide.

[0218] The solid-liquid separator 26-1 is used to filter the iron hydroxide and calcium hydroxide residues 73-1, and the solid-liquid separator 26-2 is used to filter the iron phosphate residues 73-2.

[0219] The sensors 66-1, 66-3, 66-9, 66-11, 66-13 and 66-15 are liquid level meters, 66-2, 66-4, 66-5, 66-10, 66-12 and 66-16 are pH meters, 66-6, 66-7, 66-8, 66-14 and 66-17 are ORP meters, and 68-18 is a chlorine concentration detector.

[0220] Organic waste liquid 44-1 is a solution of landfill leachate adjusted to a pH of 11 by adding alkali. Alkali is added during the reaction in tank 21-1 to maintain the pH of the reaction liquid at 11. Organic waste liquid 44-2 is a solution of organic waste liquid 44-1 that requires the addition of chlorine gas in tank 1-1 for further reaction. Alkali is added during the reaction to maintain the pH of the reaction liquid at 7.8. The cell voltage of tank 1-1 is 22V, the electrolysis current is 8A, and chlorine is electrolyzed at the anode and hydrogen is electrolyzed at the cathode.

[0221] The organic waste liquid 44-3 is obtained by adding hydrochloric acid to the waste liquid 44-2 after the oxidation treatment is completed to adjust the pH of the waste liquid 44-3 to 5 to generate hypochlorous acid for acidic oxidation reaction. The organic waste liquid 44-4 is obtained by adding the waste liquid 44-3 to the tank 1-2 for acidic electrochemical reduction treatment after the acidic oxidation reaction is completed. According to the gas-liquid mixed electrochemical reaction device used in the process, the decomposition voltage value of the organic waste liquid 44-4 is measured to be 0.4V. The power supply 5-3 is adjusted to output 0.8V higher than the decomposition voltage to operate. During the process, a large amount of hydrogen gas is input from the outside to participate in the electrochemical reaction, causing the organic pollutants in the electrolyte 44-4 to undergo a reduction reaction and also nitrate nitrogen (NO2 - 、NO3 - ) is removed by reaction. After organic waste liquid 44-5 is treated in tank 1-2 for nitrate nitrogen removal and the sum of organic amines and nitrate nitrogen reaches a concentration less than or equal to the process-set standard of 40 mg / L, waste liquid 44-4 is drained into tank 1-3, where chlorine is continued to be used to completely eliminate ammonia NH3 in waste liquid 44-5. The operating data of tank 1-3 are a tank voltage of 72V and an electrolysis current of 12A, respectively, to electrolyze chlorine and hydrogen. The total nitrogen pollutant in waste liquid 44-6 is ≤40 mg / L, completely removing nitrogen pollutants from landfill leachate in accordance with GB16889-2008.

[0222] The operation method of treating landfill leachate using a gas-liquid mixed electrochemical reaction device is as follows:

[0223] 1. Adding a starting solution to each tank in the apparatus involves adding alkali to adjust the pH of landfill leachate 42 to 11 and feeding it to chemical reaction tank 21-1. Alkali is added to adjust the pH of landfill leachate to 7.8 and feeding it to tank 1-1. Solution 44-2, which has undergone oxidation treatment in tank 1-1 for four hours, is pumped to tank 21-2. The solution, which has undergone acidic oxidation in chemical reaction tank 21-2, is pumped via pump 53-9 to tank 1-2 for hydrogenolysis and / or hydrogenation and / or electrochemical reduction to remove nitrate nitrogen. After the reaction, waste liquid 44-4 is pumped to tank 1-3 for addition of chlorine to remove NH3. After the oxidation, waste liquid 44-5 is fed to chemical reaction tank 21-3 for chlorine removal and neutralization. The corresponding organic waste liquids are fed into the corresponding tanks.

[0224] 2. Start the tail gas treatment tanks 27-1 and 27-2, start the vacuum ejectors 15-1 and 15-2, start the electrolytic cell 57, start the electrolytic cells 1-1, 1-2, 1-3 and 57, the vacuum ejector 15-1, open the chlorine bottle 80 to supply chlorine to the electrolytic cell 1-3.

[0225] 3. Place chemical reaction tank 21-1, tank 1-1, and tank 1-3 under alkaline conditions to react ammonia with hypochlorite to generate nitrogen and salt for 4 hours. The hydrogen in tank 1-2 reacts with NO2 - and / or NO3 - The removal reaction was carried out for 10 hours. During the process, samples of organic waste liquids 44-1, 44-2, and 44-5 were taken to test the NH3 content concentration, and organic waste liquid 44-4 was sampled to test NO2 - and NO3 - and the nitrogen pollutant concentration of organic amines. When the nitrogen pollutant concentration detected in the waste liquid 44-4 is ≤40 mg / L, it is considered that the treatment in tank 1-2 is completed.

[0226] 4. The solution still containing ammonia NH3 after treatment in tank 1-2 is pumped to tank 1-3 for oxidation treatment for 4 hours. No safety alarm occurs during the process. After testing, all ammonia NH3 has been eliminated and the total nitrogen content of waste liquid 44-5 is ≤40mg / L, which meets the emission standard value of GB16889-2008. It is considered that the nitrogen pollutants in the landfill leachate have been completely treated.

[0227] 5. The oxidizing exhaust gas that escapes is led to the polluted exhaust gas treatment tanks 27-1 and 27-2 for environmental protection treatment. The exhaust gas that escapes from tank 1-2 is treated with nitrogen oxide gas in tank 27-3 and the separated hydrogen exhaust gas is safely discharged through the high-altitude safety discharge pipe 98.

[0228] 6. Add ferrous chloride 72 to the waste liquid 44-6 of the chemical reaction tank 21-3 for chlorine removal, then add sodium hydroxide for neutralization and precipitation, and filter for phosphorus removal and treatment.

[0229] This example only thoroughly treated the nitrogen pollutants in the landfill leachate, without thoroughly treating the heavy metal ions and organic pollutants COD. The data and test results of the treatment of nitrogen pollutants are listed in Table 1.

[0230] Example 15

[0231] FIG20 shows Example 15 of a method for treating landfill leachate using a gas-liquid hybrid electrochemical reaction device according to the present invention. The device comprises three gas-liquid hybrid electrolytic cells, two impeller agitators, six temporary storage tanks 20, eight chemical reaction tanks 21, a buffer tank 22, four solid-liquid separators 26, two polluted tail gas treatment tanks 27, a conventional electrolytic cell 57, an automatic feed controller 65, a sensor 66, two mixed gas separation tanks 69, a chlorine cylinder 80, a high-temperature electric furnace 86, valves, and a pump.

[0232] One of the gas-liquid hybrid electrolytic cells is a Type A cell, shown in FIG8 , used for electrochemical oxidation reactions. It includes an electrolytic cell body 1-1, an electrolytic cell separator 2-1, an electrolytic anode 3-1, an electrolytic cathode 4-1, an electrolytic power supply 5-1, and vacuum jet electrolytic cell gas-liquid mixers 7-1 and 7-2. The electrolytic anode 3-1 is connected to the positive electrode of the electrolytic power supply 5-1, and the electrolytic cathode 4-1 is connected to the negative electrode of the electrolytic power supply 5-1. Two electrolytic cell dividers 2-1 are provided within the electrolytic cell body 1-1, dividing it into two electrolytic anode cell sections and one electrolytic cathode cell section. A bipolar electrode 6-1 and an insoluble anode conductor 23-1, which is directly conductively connected to the electrolytic anode, are respectively provided in the two anode cell sections. Two vacuum jet electrolytic cell gas-liquid mixers 7-1 are connected to the two anode cell sections of the electrolytic cell body via pumps 53-4 and 53-5, respectively, by liquid flow conduits, with their outlets directed toward the electrolytic anode 3-1, the insoluble anode conductor 23, and the bipolar electrode 6-1. The electrolytic cell divider 2-1 is an anion exchange membrane. The effective solution processing volume of one of the gas-liquid mixing electrolytic cells is 25 x 2 liters.

[0233] The second gas-liquid hybrid electrolytic cell is a C-2-type cell with a vertical structure (22). Three independent electrolytic units are installed in layers within the cell, performing electrochemical reduction reactions. The cell comprises an electrolytic cell body (1-2), three electrolytic anodes (3-3), three electrolytic cathodes (4-3), three electrolytic power supplies (5-3), and a combined vacuum jet and bubbling electrolytic cell gas-liquid mixer (9). The electrolytic anodes of each independent electrolytic cell are connected to the positive electrode of their corresponding electrolytic power supply, while the electrolytic cathodes of each independent electrolytic cell are connected to the negative electrode of their corresponding electrolytic power supply. The cell body (1-2) is externally connected to a liquid flow agitator (19). Furthermore, the cell body (1-2) is equipped with an insoluble anode conductor (23-2) directly electrically connected to the electrolytic anode and an insoluble cathode conductor (24) directly electrically connected to the electrolytic cathode. Furthermore, an insulating through-hole support plate (12) is provided between the electrolytic electrodes. The combined vacuum jet and bubbling electrolytic cell gas-liquid mixer 9 is connected to the electrolytic cell body via an electrolyte ion current interrupter 89 and pump 53-11, with its outlet directed toward the electrolytic electrodes and electrocatalytic components. The electrolyte flow within the electrolytic cell body 1 rises above the terminal electrode, where a bubble-containing reaction liquid deflector 93 is installed. This deflector is connected to the liquid flow agitator 19, which pumps the gas-liquid mixture back to the bottom of the electrolytic cell to re-enter the electrochemical reaction. The effective solution processing capacity of this second gas-liquid mixing electrolytic cell is 150 liters.

[0234] The third gas-liquid hybrid electrolytic cell is a C-1 type cell of the structure shown in Figure 6 , used for electrochemical reduction reactions. It includes an electrolytic cell body 1-3, electrolytic cell separators 2-3 and 2-4, an electrolytic anode 3-4, an electrolytic cathode 4-4, an electrolytic power supply 5-4, and a vacuum jet electrolytic cell gas-liquid mixer 7-2. The electrolytic anode 3-4 is connected to the positive electrode of the electrolytic power supply 5-4, and the electrolytic cathode 4-4 is connected to the negative electrode of the electrolytic power supply 5-4. Electrolytic cell body 1-3 is provided with electrolytic cell dividers 2-3 and 2-4 to divide it into an electrolytic anode cell area, an intermediate cell area, and an electrolytic cathode cell area, and a bipolar electrode 6-2 is provided in the intermediate cell area. A vacuum jet electrolytic cell gas-liquid mixer 7-2 is connected to the intermediate cell area of ​​the electrolytic cell body via a pump 53-13 as a liquid flow conduit, with its outlet facing the bipolar electrode 6-2. Electrolytic cell divider 2-3 is an anion exchange membrane, and electrolytic cell divider 2-4 is a reverse osmosis membrane. The effective treatment solution volume of the intermediate cell area is 25 liters. A bubble-containing reaction liquid flow guide 93 is provided at the electrolytic cathode.

[0235] The anolyte of tank 1-1 is organic waste liquid 44-3, and the catholyte 48-1 is sulfuric acid solution. The electrolyte of tank 1-2 is solution 44-7. The anode electrolyte of tank 1-3 is both pH 2 sulfuric acid solution, and the electrolyte of middle tank 75 is acid waste liquid 44-8.

[0236] The alkaline solution 49-1 is a sodium hydroxide solution, 49-2 is a mixture of potassium carbonate and potassium hydroxide, the acidic solution is sulfuric acid, and the ferrous salt solution 72 is a ferrous sulfate solution.

[0237] The polluted tail gas treatment tank 27-1 uses sodium hydroxide solution as the alkaline solution 49 to absorb the acidic tail gas (H2S) generated by the chemical reaction tank 21-1 for environmentally friendly treatment. The polluted tail gas treatment tank 27-2 uses sodium hydroxide solution as the alkaline solution 49-1 to absorb Cl2 and acidic gases. The mixed gas gas-liquid separators 69-1 and 69-2 use water as the absorption liquid to separate NH3, NO, and H2. The hydrogen tail gas separated by the mixed gas gas-liquid separator 69-2 is safely discharged at high altitude.

[0238] Chemical reaction tank 21-1 performs acidification and protein coagulation on the treated liquid. Chemical reaction tank 21-2 adds alkali solution to adjust the pH of organic waste liquid 44-2 to 8.5 in preparation for an alkaline oxidation reaction. Chemical reaction tank 21-3 is used to remove chlorine from organic waste liquid 44-4, neutralize it, and remove phosphorus and calcium. Chemical reaction tank 21-4 adds alkali solution 49-2 to waste liquid 44-5 to adjust the pH to 10.5, causing heavy metal ions in the waste liquid to form insoluble precipitates of carbonates and / or hydroxides. Chemical reaction tank 21-5 adjusts the pH. Tank 21-6 is used for the Fenton reaction. Chemical reaction tank 21-7 is used for chlorine oxidation to remove NH3. Chemical reaction tank 21-8 is used for chlorine removal and neutralization reactions.

[0239] The conventional electrolytic cell 57 is used to produce Cl2 and H2 as raw materials for the operation of the device. The electrolytic cell separator 2-2 is a cation exchange membrane, the anolyte is 99% sodium chloride, and the catholyte is 49% sodium hydroxide.

[0240] The sensors 66-5, 66-8, 66-9, 66-11, 66-12, 66-13, 66-16, 66-17, and 66-20 are liquid level meters, 66-1, 66-2, 66-6, 66-14, 66-18, 66-21, and 66-23 are pH meters, and 66-3, 66-4, 66-7, 66-10, 66-15, 66-19, and 66-22 are ORP meters.

[0241] The pre-treated landfill leachate 44-1 is a landfill leachate solution adjusted to a pH of 3 by acidification. After filtration, alkaline solution 49-1 is added to adjust the pH to 8.5, resulting in pre-treated landfill leachate 44-2. Pre-treated landfill leachate 44-3 is a reaction solution in a gas-liquid hybrid electrolytic cell 1-1. Alkali is added during the reaction to maintain the pH of the reaction solution at 8.5. The cell voltage is 28V, and the electrolysis current is 21A. Chlorine is electrolyzed at the anode and hydrogen is electrolyzed at the cathode. After oxidation treatment in the electrolytic cell 1-1, pre-treated landfill leachate 44-4 is obtained. Ferrous sulfate 72 and alkaline solution 49-1 are added to maintain the pH of the reaction solution at 7.5, reducing the high-valent chromium and lead ions in the wastewater to low-valent states. Phosphate precipitates are produced during the process, and filtration removes phosphorus, resulting in pre-treated landfill leachate 44-5. Alkaline solution 49-2 is added to adjust the reaction liquid to pH 10.5 to produce heavy metal carbonate and hydroxide precipitates. After filtering out the heavy metal ions, the pre-treated landfill leachate 44-6 is obtained. Subsequently, sulfuric acid is added to adjust the pH value to pH 1 and then respectively put into the second gas-liquid mixed electrolytic cell and its electrolytic cell body 1-2 and the third gas-liquid mixed electrolytic cell and its electrolytic cell body 1-3 for acidic electrochemical reduction treatment. According to the process application, the decomposition voltage value of the second gas-liquid mixed electrolytic cell for the pre-treated landfill leachate 44-7 is tested and the result is 0.4V. The three electrolytic power supplies of the second gas-liquid mixed electrolytic cell are all adjusted to output 0.4V, which is equal to the decomposition voltage value, and the operation is carried out. During the process, a large amount of hydrogen gas is input from the outside to participate in the electrochemical reaction, causing the organic pollutants in the electrolyte 44-7 to undergo a reduction reaction, and also nitrate nitrogen (NO2 - 、NO3 - ) for reaction removal; Pre-treated landfill leachate 44-8 was treated for nitrogen pollutant removal using the middle tank section 75 of electrolytic cell 1-3. The electrolysis power supply was adjusted to 76V, the electrolysis current was 30A, and the electrolysis electrodes all produced gas. After testing tanks 1-2 and 1-3 for nitrate nitrogen removal and the combined concentration of organic amines and nitrate nitrogen reached less than or equal to the process-set standard of 40 mg / L, pre-treated landfill leachates 44-7 and 44-8 were diverted to tank 20-3 for temporary storage. This was then treated as pre-treated landfill leachate 44-9 for the Fenton reaction. After solid-liquid separation, the leachate was pumped to tank 20-5, where chlorine gas was used to completely eliminate ammonia NH3 from pre-treated landfill leachate 44-11. The total nitrogen pollutants in the pre-treated landfill leachate 44-12 are ≤40mg / L, and the nitrogen pollutants in the landfill leachate are completely removed according to the GB16889-2008 standard.

[0242] The filter residues 73-1, 73-2, 73-3, and 73-4 all contain pollutants and are classified as hazardous waste. The filter residue 73-5 is ferric hydroxide containing organic pollutants, which can be decomposed at high temperature to produce ferric oxide that can be used as other raw materials.

[0243] The operation method of treating landfill leachate using a gas-liquid mixed electrochemical reaction device is as follows:

[0244] 1. Add the corresponding starting liquid to each tank in the device, and connect the power to start the automatic detection and feeding controller, process the sensor detection data of each tank and control the device to run according to the pre-programmed program.

[0245] 2. Sulfuric acid is added to the landfill leachate 42 in the chemical reaction tank 21-1 to acidify the pH to 3 and coagulate the protein in the waste liquid. After solid-liquid separation, the filtrate is added to one of the gas-liquid hybrid electrochemical devices and treated for 12 hours. During the oxidation treatment, the conventional electrolytic cell 57 is started to produce chlorine and hydrogen.

[0246] 3. The waste liquid 44-3 after oxidation treatment is treated to remove phosphorus and heavy metal ions to obtain acidic waste liquid 44-6.

[0247] 4. Waste liquid 44-6 is respectively fed into tank 1-2 and tank 1-3 for electrochemical reduction treatment. During the process, the tail gas escaping from tank 1-2 is separated in tank 69-1 and the hydrogen obtained is drained to tank 1-3 for reuse, while NO reacts with hydrogen peroxide to produce HNO3. The tail gas from tank 1-3 is treated in tank 69-2 and the hydrogen tail gas is discharged into the air.

[0248] 5. After the reaction of tank 1-2 and tank 1-3 for 12 hours, the organic waste liquids 44-7 and 44-8 were tested for NO2 - and NO3 - and nitrogen pollutant content concentration of organic amines. When the test results show that the content concentration is ≤40 mg / L, it is considered that the waste liquid in tank 1-2 and tank 1-3 has been treated according to the process standards.

[0249] 6. The waste liquid still containing NH3 after treatment in tanks 1-2 and 1-3 is pumped to tank 21-6 for Fenton reaction to remove organic pollutants. After Fenton treatment, the filtrate 44-10 is temporarily stored in tank 20-5.

[0250] 7. The waste liquid 44-10 is pumped to the chemical reaction tank 21-7 for chlorine oxidation treatment. The pH value of the reaction liquid is controlled to pH 8.8 and the reaction is carried out for 6 hours to completely eliminate the ammonia NH3 in the reaction liquid. The total nitrogen content of the waste liquid 44-12 is ≤40 mg / L, which meets the emission standard value of GB16889-2008.

[0251] 8. The oxidizing tail gas that escapes is led to the polluted tail gas treatment tank 27-2 for environmental protection treatment.

[0252] 9. Add sulfuric acid to the waste liquid 44-12 of the chemical reaction tank 21-8 for neutralization and pump it into the tank 20-6 for temporary storage before discharge.

[0253] In addition to thoroughly treating the nitrogen pollutants in the landfill leachate, this embodiment also treated heavy metal ions, phosphorus pollutants, and organic pollutants to meet standards. The data and test results for the treatment of nitrogen and other pollutants are listed in Table 1.

[0254] Example 16

[0255] FIG21 shows Example 16 of a method for treating landfill leachate using a gas-liquid hybrid electrochemical reaction device according to the present invention. The device includes two gas-liquid hybrid electrochemical devices, two vacuum ejectors 15, a hot and cold temperature exchanger 17, two impeller agitators 18, seven temporary storage tanks 20, six chemical reaction tanks 21, four solid-liquid separators 26, two polluted tail gas treatment tanks 27, a conventional electrolytic cell 57, an automatic feed controller 65, a sensor 66, a mixed gas separator 69, and multiple valves and pumps.

[0256] One of the gas-liquid hybrid electrochemical devices described is a C-2 cell with a circular electrode distribution structure (Figure 10), used for electrochemical reduction reactions. It includes an electrolytic cell body 1-1, an electrolytic cell separator 2-1, eight electrolytic anodes 3-1, an electrolytic cathode 4-1, eight electrolytic power supplies 5-1, and a combined vacuum jet and bubbling electrolytic cell gas-liquid mixer 9. The electrolytic cathode 4-1 serves as the central electrode, connected to the negative electrodes of the eight electrolytic power supplies 5-1. The eight electrolytic anodes 3-1 are arranged around this central electrode and are each connected to the positive electrodes of their respective electrolytic power supplies 5-1. The electrolytic anodes 3-1 in the electrolytic cell body 1-1 are independently separated by insulating partitions, and the electrolytic anodes and electrolytic cathodes are structurally improved for electrocatalytic performance: the electrolytic anodes 3-1 and electrolytic cathodes 4-1 are both parallel-connected electrodes, and the angle formed by their parts with the straight line of gas-liquid mixture ejection from the electrolytic cell gas-liquid mixer is greater than 0° and less than or equal to 90°; the electrolytic cell gas-liquid mixer 9, which is a combination of vacuum jet and bubbling types, is connected to the electrolytic cell body as a liquid flow pipeline through a temporary storage tank 20-2 or a temporary storage tank 20-3 and a pump, and its outlet faces the electrolytic anode 3-1.

[0257] The second gas-liquid mixing electrochemical device is an A-type cell with a circular electrode distribution structure as shown in Figure 11, used for electrochemical oxidation reactions. It includes an electrolytic cell body 1-2, an electrolytic cell separator 2-1, multiple electrolytic anodes 3-2, an electrolytic cathode 4-2, eight electrolytic power supplies 5-2, and a vacuum jet electrolytic cell gas-liquid mixer 7. The electrolytic cathode 4-2 serves as the central electrode and is connected to the negative electrode of the electrolytic power supply 5-2. Multiple electrolytic anodes 3-2 are arranged around the central electrode and connected to the positive electrode of the electrolytic power supply 5-2. The electrolytic cell body 1-2 is provided with an electrolytic cell separator 2-1, dividing it into an electrolytic anode cell area and an electrolytic cathode cell area. A bipolar electrode 6 is provided in the anode cell area. The vacuum jet electrolytic cell gas-liquid mixer 7 is connected to the electrolytic cell body anode cell area via an electrolyte ion current interrupter 89 and a pump as a liquid flow conduit, with its outlet facing the bipolar electrode 6. The electrolytic cell separator 2-1 is an anion exchange membrane.

[0258] The electrolyte of the tank 1-1 is an organic waste liquid 44-3 with a pH of 6. The electrolyte of the tank 1-2 is an alkaline organic waste liquid 44-6, and the cathode electrolyte is a sodium chloride solution 99.

[0259] The conventional electrolytic cell provides chlorine and hydrogen for the operation of the device, and its electrolytic cell separator 2-2 is a cation exchange membrane, its anolyte is a sodium chloride solution 99, and its cathode electrolyte is sodium hydroxide as an alkaline solution 49-1.

[0260] The alkaline solution 49-1 is a sodium hydroxide solution, and the alkaline solution 49-2 is a mixture of sodium carbonate, sodium bicarbonate, and sodium hydroxide. The acidic solution is sulfuric acid 50. The ferrous salt 72 is ferrous sulfate.

[0261] The tail gas absorption liquids in the polluted tail gas treatment tank 27-1 and the polluted tail gas treatment tank 27-2 are both sodium hydroxide solutions. The polluted tail gas treatment tank 27-1 is used to absorb the acidic pollutant gases, including the escaped hydrogen sulfide, released by the reaction of tanks 21-1 and 21-2. The polluted tail gas treatment tank 27-2 absorbs the waste gas released from each tank in the device for environmental protection treatment.

[0262] The temporary storage tank 20-2 and the temporary storage tank 20-3 are combined to function as an electrolyte ion current interrupter, wherein the tank is installed with solution flow area enlarging guide plates 67-1 and 67-2 to facilitate the escape of water-insoluble NO and H2 and lead them to the tank 69 for separation treatment.

[0263] Chemical reaction tank 21-1 is used to treat landfill leachate to kill pathogens and acidify it to coagulate proteins. Chemical reaction tank 21-2 is used to perform the Fenton reaction and remove phosphorus and calcium. Chemical reaction tank 21-3 is used to adjust the pH of the solution. Chemical reaction tank 21-4 is used to perform the Fenton reaction on the wastewater and remove phosphorus and calcium. Chemical reaction tank 21-5 is used to increase the pH of the reaction solution to produce heavy metal carbonates and their hydroxide precipitates. Chemical reaction tank 21-6 is used to remove NH3 by chlorine oxidation. Chemical reaction tank 21-7 is used for chlorine removal and neutralization.

[0264] The sensors 66-1, 66-3, 66-7, 66-8, 66-9, 66-10, 66-13, 66-16, and 66-19 are liquid level gauges, 66-2, 66-4, 66-6, 66-11, 66-14, 66-17, and 66-20 are pH meters, and 66-5, 66-12, 66-15, 66-18, and 66-21 are ORP meters.

[0265] Pre-treated landfill leachate 44-1 is a mixture of landfill leachate, hydrogen peroxide, and sulfuric acid. Pre-treated landfill leachate 44-2 is a Fenton reaction solution. Acid is added to tank 21-3 to adjust the pH to less than pH 0.01. Wastewater 44-3, with a pH less than pH 0.01, serves as the acidic electrolyte in tank 1-1. Acidic electrolytes help reduce the deposition of calcium hydroxide and magnesium hydroxide on the electrodes, which otherwise reduces electrolysis efficiency. Pre-treated landfill leachate 44-4 is a Fenton reaction solution, with the pH adjusted to pH 7 to produce an iron phosphate precipitate. Pre-treated landfill leachate 44-5 reacts with an alkaline solution 49-2 to produce a heavy metal precipitate. Pre-treated landfill leachate 44-6 undergoes an oxidative NH3 removal reaction in tank 1-2. Pre-treated landfill leachate 44-7 is the result of further chlorine addition to pre-treated landfill leachate 44-6 to remove NH3. The pre-treated landfill leachate 44-8 is a solution after dechlorination and neutralization treatment.

[0266] During electrolytic cell 1-1's processing, the decomposition voltage of the electrolyte in the gas-liquid hybrid electrochemical reaction device used in the process was measured to be 0.4V. Therefore, electrolytic power supply 5-1 applied a 0.7V voltage difference between electrolytic anode 3-1 and electrolytic cathode 4-1. Each electrolytic power supply output current was 0.02A, resulting in a total electrolytic current of 0.016A for cell 1-1. The operating parameters for electrolytic cell 1-2 were an electrolytic power supply 5-2 output voltage of 28V and an electrolytic current of 6A, resulting in the deposition of chlorine and hydrogen.

[0267] The filter residue 73-1 is the coagulated protein in the landfill leachate. Filter residue 73-2 is the iron hydroxide precipitate containing pollutants produced by adjusting the pH value after the first Fenton reaction. Filter residue 73-3 is the iron hydroxide precipitate produced by adjusting the pH value of the reaction solution to pH 7 after the second Fenton reaction to produce phosphorus compounds. Filter residue 73-4 is the heavy metal precipitate.

[0268] The operation method of treating landfill leachate using a gas-liquid mixed electrochemical reaction device is as follows:

[0269] 1. Add the corresponding starting liquid to each tank in the device, and connect the power to start the automatic detection and feeding controller, process the sensor detection data of each tank and control the device to run according to the pre-programmed program.

[0270] 2. In chemical reaction tank 21-1, hydrogen peroxide is added to the landfill leachate to kill pathogens, and sulfuric acid is added to adjust the pH to pH 3.5 to coagulate the protein in the waste liquid. During the reaction, the escaping exhaust gas is directed to the polluted exhaust gas treatment tank 27-1 for treatment. The solid-liquid mixture obtained after the reaction is separated into solid and liquid by filter press 26-1, and the acidic filtrate is directed to chemical reaction tank 21-2.

[0271] 3. First add sulfuric acid into the chemical reaction tank 21-2 to generate NO3 - with Fe 2+ The reaction generates NO↑, and then hydrogen peroxide, ferrous sulfate, and alkaline solution 49-1 are added to maintain the pH of the reaction solution at 3.5 for Fenton reaction to generate NO2 - Oxidized to NO3 - After completion, continue to add alkaline solution 49-1 to adjust the pH of the reaction solution to 6 to produce iron hydroxide precipitate and remove part of the calcium and phosphorus at the same time. The reaction tail gas containing O2 is led to the polluted tail gas treatment tank 27-1 to react with NO to generate dilute nitric acid solution.

[0272] 4. The solid-liquid mixture in the chemical reaction tank 21-2 is subjected to solid-liquid separation. The resulting filtrate is drained through the temporary storage tank 20-2 and / or the temporary storage tank 20-3 and enters one of the gas-liquid hybrid electrolytic cells for electrochemical reduction treatment. The exhaust gas emitted during the process is drained to the mixed gas gas-liquid separator 69 for treatment. After 16 hours of reaction, if the sum of the organic amine and nitrate nitrogen in the reaction liquid is detected to be less than or equal to 40 mg / L, the reduction reaction for removing nitrate nitrogen is considered complete.

[0273] 5. The solution that has completed the reaction in one of the gas-liquid hybrid electrolytic cells is pumped into the chemical reaction tank 21-3 and ferrous sulfate is first added to remove the remaining NO3 -The temperature of the reaction solution is raised to 50° C. by the hot-cold temperature exchanger 17 to carry out the second Fenton reaction. After the Fenton reaction is completed, the alkali solution 49-1 is added to adjust the pH value to pH 7 so that iron hydroxide and iron phosphate precipitates appear in the reaction solution and calcium and phosphorus are removed at the same time. The filtrate is drained into the chemical reaction tank 21-4 for solid-liquid separation.

[0274] 6. Under the control of the automatic detection and feeding controller, an alkaline solution 49-2 is added to the pre-treated landfill leachate 44-5 in the chemical reaction tank 21-4 to cause the reaction liquid to produce precipitates of heavy metal carbonates and hydroxides. The heavy metal ions are removed by solid-liquid separation, and the filtrate is the pre-treated landfill leachate 44-6.

[0275] 7. The pre-treated landfill leachate 44-6 is subjected to an electrochemical oxidation reaction in tank 1-2 to remove NH3, and the pH value of the reaction liquid is maintained at 10 for a reaction time of 13 hours. It is then fed into the chemical reaction tank 21-5 to continue the chlorine oxidation reaction to remove NH3. The pH value of the reaction liquid is maintained at pH 9.2 for a reaction time of 1.5 hours. The ORP meter 66-17 controls the output current of the electrolysis power supply 5-3 to stabilize the redox potential of the pre-treated landfill leachate 44-7 as the reaction liquid at 460mv.

[0276] 8. After the total nitrogen of the pre-treated landfill leachate 44-7 is tested and the result is less than or equal to 40 mg / L, the 44-7 solution is drained to tank 21-6 for dechlorination and neutralization treatment. If the heavy metal ion concentration, phosphorus, nitrogen and COD indicators meet the emission standards of GB16889-2008, it is discharged.

[0277] The processed data and test results are listed in Table 1.

[0278] Table 1 Data and test results of landfill leachate treatment by electrochemical reaction device

[0279] Comparative Example 1

[0280] This comparative example uses the method of Example 1, except that a conventional electrolytic cell was used to treat nitrogen pollutants in landfill leachate. This conventional electrolytic cell lacks a gas-liquid mixer and does not employ any electrocatalytic structure. The treatment data and test results are listed in Table 1.

[0281] Comparative Example 2

[0282] This comparative example adopts the method of Example 1, except that only a common electrolysis anode and a common electrolysis cathode are used without any electrocatalytic structure. The processing data and test results are listed in Table 1.

[0283] Comparative Example 3

[0284] This comparative example adopts the method of Example 1, except that the electrolyzer gas-liquid mixer is not included. The processing data and test results are listed in Table 1.

[0285] Table 1 Data and test results of landfill leachate treatment by electrochemical reaction device

[0286] Table 1

[0287] By comparing the result data of Example 12 with those of Comparative Examples 1-3, it can be seen that the combination of the gas-liquid mixture in the electrolyzer and the electrocatalytic structure can achieve a significant electrocatalytic effect of the electrochemical reaction.

[0288] The embodiments of the present invention can achieve production with lower energy consumption when the electrochemical reaction is performed at a voltage less than or equal to the electrolyte decomposition voltage, or when the electrochemical reaction is performed at a voltage slightly higher than the electrolyte decomposition voltage when there is sufficient gas participating in the reaction so that it is difficult for electrical components to electrolyze gas.

Claims

1. A gas-liquid mixed electrochemical reaction device for treating landfill leachate, comprising an electrolytic cell mainly composed of an electrolytic cell body, an electrolytic anode, an electrolytic cathode, and an electrolytic power supply, wherein: The electrolysis anode is connected to the positive electrode of the electrolysis power supply, and the electrolysis cathode is connected to the negative electrode of the electrolysis power supply. The electrolytic cell also includes at least one electrolytic cell gas-liquid mixer and an electrocatalytic component, forming a gas-liquid mixing electrolytic cell. The outlet of the electrolytic cell gas-liquid mixer is oriented toward or located in the electrolytic cell body, and is used to bring the gas-liquid mixture obtained by mixing the electrolyte in the electrolytic cell with the reaction gas into contact with the electrocatalytic component. The electrocatalytic component adopts any one or more of the following methods: Electrocatalytic method (1): at least one electrocatalytic component is arranged in the electrolytic cell body, and the outlet of the electrolytic cell gas-liquid mixer is directed toward the electrocatalytic component and / or the electrolytic anode and / or the electrolytic cathode; Electrocatalytic method (2): The electrolytic anode and / or the electrolytic cathode are improved in electrocatalytic performance structure, at least one of the electrolytic anode and the electrolytic cathode is two or more parallel-connected electrodes, and the outlet of the electrolytic tank gas-liquid mixer faces the electrolytic anode and / or the electrolytic cathode with improved electrocatalytic performance structure; Electrocatalytic method (3): The electrocatalytic performance structure of the electrolytic anode and / or the electrolytic cathode is improved, and the angle formed by a part or the whole of at least one of the electrolytic anode and the electrolytic cathode and the gas-liquid mixture ejection straight line of the electrolytic tank gas-liquid mixer is greater than 0° and less than or equal to 90°, and the outlet of the electrolytic tank gas-liquid mixer is oriented toward the electrolytic anode and / or the electrolytic cathode with the improved electrocatalytic performance structure.

2. The gas-liquid hybrid electrochemical reaction device according to claim 1, characterized in that: The electrolytic cell gas-liquid mixer has an inlet and at least two outlets, or has a structure with a liquid inlet, an air inlet and an outlet. When the electrolytic cell gas-liquid mixer has an inlet and at least two outlets, the outlet extends into the electrolytic cell body and is used to disperse the reaction gas or gas-liquid mixture into the electrolyte in the electrolytic cell for gas-liquid mixing; when the electrolytic cell gas-liquid mixer has a liquid inlet, an air inlet and an outlet, the liquid inlet is connected to the electrolytic cell body by a pipeline, and the outlet is directed toward or extends into the electrolytic cell body, and is used to input the electrolyte in the electrolytic cell into the gas-liquid mixer so that it is mixed with the reaction gas entering the gas-liquid mixer and then returned to the electrolytic cell.

3. The gas-liquid hybrid electrochemical reaction device according to claim 2, characterized in that: The electrocatalytic component in the electrocatalytic method (1) is arranged in the electrolytic cell body and can be located below the electrolyte liquid level, and is used to realize the electrochemical catalytic reaction ability under the action of the electric field force; the electrocatalytic component is a bipolar electrode and / or an insoluble conductor.

4. The gas-liquid hybrid electrochemical reaction device according to claim 3, characterized in that: The gas-liquid hybrid electrochemical reaction device is divided into the following three types: (1) Type A cell: The electrolytic cell gas-liquid mixer uses self-electrolyzed gas as the gas source for the reaction. The gas inlet of the electrolytic cell gas-liquid mixer is connected to the top of the electrolytic cell area where its outlet is located. The gas electrolyzed by the electrolytic electrode in the cell area is mixed with the electrolyte in the cell area by the electrolytic cell gas-liquid mixer to form a gas-liquid mixture, which then contacts the electrolytic electrode and / or electrocatalytic component in the cell area to undergo an electrochemical reaction. (2) Type B cell: The electrolytic cell gas-liquid mixer uses both self-electrolyzed gas and external input gas as gas sources for the reaction. The gas inlet of the electrolytic cell gas-liquid mixer is connected to the top of the electrolytic cell area where its outlet is located, i.e., the anode area. It is also connected to a gas source outside the electrolytic cell. The gas electrolyzed by the electrolytic anode in the electrolytic cell area is combined with the gas from the outside and mixed with the electrolyte in the electrolytic cell area, and then contacts the electrolytic electrodes and / or electrocatalytic components in the electrolytic cell area to carry out an electrochemical reaction. (3) C-type cell: The electrolytic cell gas-liquid mixer uses external input gas as the gas source for participating in the reaction. The gas inlet of the electrolytic cell gas-liquid mixer is connected to a cell area in the same electrolytic cell that is not connected to the liquid flow and / or a gas source outside the electrolytic cell. The electrolytic cell gas-liquid mixer mixes the gas from outside the cell area with the electrolyte in the cell area to form a gas-liquid mixture, which contacts the electrolytic electrodes and / or electrocatalytic components of the cell area to perform an electrochemical reaction.

5. A method for treating landfill leachate using the above-mentioned gas-liquid mixed electrochemical reaction device, characterized in that: The following steps are involved: (1) Using the gas-liquid hybrid electrochemical reaction device, using the liquid to be treated as the electrolyte of the gas-liquid hybrid electrolytic cell or as the electrolyte of at least one cell zone in the electrolytic cell, and connecting the electrolysis power supply; the liquid to be treated is landfill leachate and / or landfill leachate that has been pre-treated; (2) starting at least one electrolytic cell gas-liquid mixer, drawing oxidizing gas and / or reducing gas into the treated liquid for gas-liquid mixing, and then contacting the mixed gas with at least one of the electrolytic anode and / or electrolytic cathode with improved electrocatalytic structure and the electrocatalytic component, and utilizing the electrocatalytic component to exert electrocatalytic effect to oxidize and / or reduce the substances to be treated in the treated liquid.

6. The method for treating landfill leachate according to claim 5, characterized in that: When power is applied for electrolysis, the gas-liquid mixture containing the oxidizing gas is brought into contact with the negatively charged components in the gas-liquid hybrid electrolytic tank to react, and the treated liquid is brought into contact with the positively charged components in the device to perform an oxidation reaction; and / or when power is applied for electrolysis, the gas-liquid mixture containing the reducing gas is brought into contact with the positively charged components in the gas-liquid hybrid electrolytic tank to react, and the treated liquid is brought into contact with the negatively charged components in the device to perform at least one of a hydrogenolysis reaction, a hydrogenation reaction, and a reduction reaction.

7. The method for treating landfill leachate according to claim 6, wherein: The pre-treated landfill leachate in step (1) is landfill leachate that has undergone chemical reaction and / or physical treatment but still needs to be further treated for environmental protection, specifically landfill leachate that has undergone at least one of chemical reaction, pH adjustment, component addition, component concentration adjustment, and solid-liquid separation. The oxidizing gas in step (2) is at least one selected from ozone, oxygen, and chlorine; and the reducing gas is hydrogen.

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