Electrochemical device and method for treating high-concentration organic wastewater

Abstract

The invention relates to the technical field of wastewater treatment, and discloses an electrochemical device and a treatment method of high-concentration organic wastewater. The electrochemical device includes a reaction vessel, and an anode, a cathode, and a particle electrode disposed within the reaction vessel, at least one of the anode and the cathode including a first electrode layer, a second electrode layer, and a metal layer disposed between the first electrode layer and the second electrode layer. Wherein the metal layer contains a metal and b metal, the a metal is copper, and the b metal is selected from at least one of iron, nickel and zinc. When the electrochemical device is used for treating high-concentration organic wastewater, the ammonia nitrogen content and the COD content of effluent can be effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to an electrochemical device. Furthermore, this invention also provides a method for treating high-concentration organic wastewater using the aforementioned electrochemical device. Background Technology

[0002] Industrial wastewater refers to wastewater and waste liquid discharged during industrial processes. It contains industrial raw materials, intermediate products, by-products, and pollutants generated during production, and is a major cause of environmental pollution, especially water pollution. High-concentration organic wastewater generated during operations in typical chemical industries such as pharmaceuticals, dyes, and petrochemicals is characterized by large volume, high salinity, high color, and difficulty in degradation; direct discharge can have a significant impact on the surrounding environment. Although these companies treat their wastewater before discharge to protect the ecological environment, the chemical oxygen demand (COD) and ammonia nitrogen content of the treated wastewater often fail to meet discharge requirements.

[0003] COD is a chemically measured amount of reducing substances in a water sample that require oxidation. It represents the oxygen equivalent of substances (generally organic matter) that can be oxidized by strong oxidants in wastewater, wastewater treatment plant effluent, and polluted water. It is an important and relatively quick-to-measure parameter for organic pollution in studies of river pollution and the properties of industrial wastewater, as well as in the operation and management of wastewater treatment plants.

[0004] Ammonia nitrogen refers to combined nitrogen that exists in the form of ammonia or ammonium ions, that is, in water as free ammonia (NH3) and ammonium ions (NH4). + Nitrogen exists in the form of ammonia nitrogen, which is a nutrient in water bodies and can lead to eutrophication. It is a major oxygen-consuming pollutant in water bodies and is toxic to fish and some aquatic organisms. Ammonia nitrogen can be converted into nitrite under certain conditions. If consumed for a long time, the nitrite in the water will combine with proteins to form nitrosamines, which are strong carcinogens and extremely harmful to human health.

[0005] The following are some industrial technologies for simultaneously treating COD and ammonia nitrogen: 1. The traditional A / O process, a combination of anaerobic and aerobic processes, removes ammonia nitrogen from COD. In the anaerobic stage, denitrifying bacteria convert nitrate nitrogen into nitrogen gas with the help of a carbon source, simultaneously removing COD. In the aerobic stage, ammonia nitrogen is oxidized to nitrate nitrogen, and biodegradable COD is removed from the effluent from the anaerobic stage. The disadvantages of this process are that it consumes a large amount of carbon source, and when treating high-concentration organic wastewater, nitrifying bacteria are greatly affected by the impact, affecting their effectiveness and leading to substandard COD and ammonia nitrogen content in the effluent.

[0006] 2. Short-cut nitrification and denitrification processes involve oxidizing ammonia nitrogen to nitrite nitrogen in the aerobic stage, followed by the reduction of nitrite nitrogen to nitrogen gas. By omitting the nitrate nitrogen step, 25% of oxygen, 40% of carbon source, and 20% of carbon emissions are saved. However, its operation remains unstable and it is not suitable for treating high-concentration organic wastewater.

[0007] 3. Traditional electrocatalytic oxidation: In the removal of COD and ammonia nitrogen, the anodic oxidation process generates hydroxyl radicals, hypochlorous acid, and intermediate products to remove COD. In the removal of ammonia nitrogen, chloride ions are required. Chloride ions generate hypochlorite ions at the anode, and hypochlorite ions react with ammonia nitrogen to generate nitrogen gas, thereby removing ammonia nitrogen.

[0008] Existing electrochemical reactors employ two-dimensional or three-dimensional electrode structures. Two-dimensional electrodes have both the anode and cathode connected to a power source, resulting in anodic and cathodic reactions respectively. Their advantages include simple structure and clear mechanism, but disadvantages include small electrode area and mutual interference between the anode and cathode. Three-dimensional electrodes, based on two-dimensional electrodes, add a granular packed bed, where the granular electrode undergoes anodic and cathodic reactions under polarization. Their advantages include fast mass transfer rates and high current efficiency, but their disadvantage is susceptibility to clogging. However, neither the aforementioned two-dimensional nor three-dimensional electrochemical reactors have solved the problem of fully utilizing electrochemical products; that is, there is still significant room for improvement in current efficiency, and the ammonia nitrogen content and COD of the organic wastewater treated by these reactors need further reduction. Summary of the Invention

[0009] The purpose of this invention is to overcome the problem that the ammonia nitrogen content and COD of organic wastewater treated by electrochemical reactors in the prior art still need to be further reduced, and to provide an electrochemical device and a method for treating high-concentration organic wastewater. When used for the treatment of high-concentration organic wastewater, the electrochemical device can effectively reduce the ammonia nitrogen content and COD content of the effluent.

[0010] To achieve the above objectives, a first aspect of the present invention provides an electrochemical device comprising a reaction vessel and an anode, a cathode, and a particulate electrode disposed within the reaction vessel. At least one of the anode and the cathode comprises a first electrode layer, a second electrode layer, and a metal layer disposed between the first electrode layer and the second electrode layer. The metal layer contains a metal (a) and a metal (b), wherein the a metal is copper and the b metal is selected from at least one of iron, nickel, and zinc.

[0011] Preferably, both the anode and the cathode include a first electrode layer, a second electrode layer, and a metal layer disposed between the first electrode layer and the second electrode layer.

[0012] Preferably, the content of the a metal in the metal layer is 2-30 wt%, more preferably 10-25 wt%.

[0013] Preferably, the thickness ratio of the first electrode layer, the metal layer, and the second electrode layer is 0.1-1:1:0.1-1.

[0014] Preferably, the first electrode layer and the second electrode layer are each independently a graphite layer or a titanium-ruthenium-iridium alloy layer.

[0015] Preferably, the electrochemical device further includes an aeration structure disposed inside the reaction vessel.

[0016] Preferably, the metal layer has a porous structure, and the porosity of the metal layer 22 is 5-35%.

[0017] Preferably, multiple sets of anode, cathode and particulate electrode are provided, and the particulate electrode is disposed between the anode and the cathode.

[0018] Preferably, the particulate electrode is a graphite particle with a particle size of 1-20 mm.

[0019] Preferably, the reaction vessel is also provided with a sludge discharge port.

[0020] A second aspect of the present invention provides a method for treating high-concentration organic wastewater, the method comprising: injecting the high-concentration organic wastewater into the electrochemical device described in the first aspect to perform an electrocatalytic reaction.

[0021] Preferably, the electrocatalytic reaction takes 20-40 minutes.

[0022] Through the above technical solution, the electrochemical device provided by the present invention configures at least one of the anode and cathode as including a first electrode layer, a second electrode layer, and a metal layer disposed between the first electrode layer and the second electrode layer, wherein the metal layer is defined as containing metal a and metal b, where metal a is copper and metal b is selected from at least one of iron, nickel, and zinc. During the electrocatalytic process, the metal layer with the above-mentioned special structure can enhance the catalytic activity of the cathode and / or anode, further improving the electrocatalytic effect, significantly increasing the current efficiency and pollutant removal capacity within the reaction vessel, and thus further reducing the ammonia nitrogen content and COD in the effluent, achieving the goal of environmental protection. Its economic, social, and environmental benefits are significant. Especially in low-concentration wastewater, the effect of removing organic matter and ammonia nitrogen is significantly improved compared to traditional electrocatalysis. The setting of the granular electrode can enhance the catalytic activity of the cathode and anode, further reducing the ammonia nitrogen content and COD in the effluent. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of an electrochemical device provided in one embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the anode in an electrochemical device provided in one embodiment of the present invention.

[0024] Explanation of reference numerals in the attached figures 1. Reaction vessel; 2a. Anode; 2b. Cathode; 21. First electrode layer; 22. Metal layer; 23. Second electrode layer; 3. Particle electrode; 4. Aeration structure; 5. Power supply; 6. Blower. Detailed Implementation

[0025] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connection" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to abutment; they can refer to the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features.

[0028] One basic embodiment of the present invention provides an electrochemical device, such as... Figure 1 and Figure 2 As shown, the electrochemical device includes a reaction vessel 1 and an anode 2a, a cathode 2b and a particulate electrode 3 disposed within the reaction vessel 1. At least one of the anode 2a and the cathode 2b includes a first electrode layer 21, a second electrode layer 23 and a metal layer 22 disposed between the first electrode layer 21 and the second electrode layer 23. The metal layer 22 contains metal a and metal b, where metal a is copper and metal b is selected from at least one of iron, nickel and zinc.

[0029] The electrochemical device provided in the above-described basic embodiment of the present invention, in use, involves injecting the wastewater to be treated into the reaction vessel 1, connecting the anode 2a to the positive terminal of the power supply 5, connecting the cathode 2b to the negative terminal of the power supply 5, turning on the power supply 5 and setting the voltage of the power supply 5, and then conducting an electrocatalytic reaction on the wastewater through the anode 2a, cathode 2b, and particulate electrode 3. After the reaction is completed, the treated wastewater is discharged from the reaction vessel 1, which is the effluent.

[0030] The electrochemical device provided by the above-described basic embodiment of the present invention configures at least one of the anode 2a and cathode 2b as including a first electrode layer 21, a second electrode layer 23, and a metal layer 22 disposed between the first electrode layer 21 and the second electrode layer 23. The metal layer 22 is defined as containing metal a and metal b, where metal a is copper and metal b is selected from at least one of iron, nickel, and zinc. During the electrocatalytic process, the metal layer 11 with the above-described special structure can enhance the catalytic activity of the cathode 2b and / or the anode 2a, further improving the electrocatalytic effect, significantly increasing the current efficiency and pollutant removal capacity within the reaction vessel 1, and thereby further reducing the ammonia nitrogen content and COD in the effluent, achieving the goal of environmental protection. Its economic, social, and environmental benefits are significant. In particular, the effect of removing organic matter and ammonia nitrogen from low-concentration wastewater is significantly improved compared to traditional electrocatalysis.

[0031] According to the present invention, the anode 2a and cathode 2b are prepared by first placing the first electrode layer 21 on a flat ground or a flat heating plate, placing titanium or stainless steel wires with a diameter of 2-20 mm along the edge, then uniformly covering it with a metal layer 22, and then covering it with a second electrode layer 23, and welding it along the placed titanium or stainless steel wires to obtain the corresponding anode 2a and cathode 2b.

[0032] In one specific embodiment of the present invention, both the anode 2a and the cathode 2b include a first electrode layer 21, a second electrode layer 23, and a metal layer 22 disposed between the first electrode layer 21 and the second electrode layer 23. By configuring both the anode 2a and the cathode 2b to include the first electrode layer 21, the second electrode layer 23, and the metal layer 22 disposed between the first electrode layer 21 and the second electrode layer 23, the ammonia nitrogen content and COD in the effluent can be further reduced.

[0033] Preferably, in the metal layer 22, the content of α-metal is 2-30 wt%, which can be 2 wt%, 4 wt%, 6 wt%, 8 wt%, 10 wt%, 12 wt%, 14 wt%, 16 wt%, 18 wt%, 20 wt%, 22 wt%, 24 wt%, 26 wt%, 28 wt%, 30 wt%, or any value within any two of the above ranges. Studies have found that controlling the α-metal oxide in the metal layer 22 within the above range can further reduce the ammonia nitrogen content and COD in the effluent. Further preferably, considering the ability to further reduce the ammonia nitrogen content and COD in the effluent, the content of α-metal in the metal layer 22 is 10-25 wt%.

[0034] Preferably, the thickness ratio of the first electrode layer 21, the metal layer 22, and the second electrode layer 23 is 0.1-1:1:0.1-1. Studies have found that controlling the thickness ratio of the first electrode layer 21, the metal layer 22, and the second electrode layer 23 in the anode 2a and / or the cathode 2b within the above-mentioned range can further reduce the ammonia nitrogen content and COD in the effluent.

[0035] The first electrode layer 21 and the second electrode layer 23 can be any type of electrode structure. In one specific embodiment of the invention, the first electrode layer 21 and the second electrode layer 23 are each independently a graphite layer or a titanium-ruthenium-iridium alloy layer. Specifically, the first electrode layer 21 can be a graphite layer or a titanium-ruthenium-iridium alloy layer, and the second electrode layer 23 can also be a graphite layer or a titanium-ruthenium-iridium alloy layer. Using a graphite layer or a titanium-ruthenium-iridium alloy layer as the electrode material can effectively improve electrolysis efficiency. Both the aforementioned graphite layer and titanium-ruthenium-iridium alloy layer are commercially available.

[0036] In one specific embodiment of the present invention, the electrochemical device further includes an aeration structure 4 disposed inside the reaction vessel 1. Specifically, the aeration structure 4 is connected to a blower 6 or a gas generator, which can be a low-pressure blower, a forced draft fan, etc. By setting up the aeration structure 4, the wastewater to be tested in the reaction vessel 1 can be mixed more evenly, preventing the low concentration of pollutants at the electrodes from reducing the reaction effect, and effectively reducing the ammonia nitrogen content and COD in the effluent.

[0037] According to the present invention, the aeration structure 4 can be any structure capable of achieving aeration, such as a perforated aeration pipe, a microporous aeration pipe, or other conventional aeration pipe. In actual use, the aeration structure 4 is positioned near the bottom of the reaction vessel 1, below the self-catalytic porous anode 2a and the self-catalytic porous cathode 2b.

[0038] In one specific embodiment of the present invention, an electrode fixing groove is provided inside the reaction vessel 1 for fixing the anode 2a and the cathode 2b. This effectively fixes the anode 2a, the cathode 2b, and the particulate electrode 3, preventing electrode displacement during electrolysis from affecting the overall electrolysis effect. It also facilitates the insertion and removal of the electrodes within the reaction vessel 1.

[0039] The electrode fixing groove can be a hollow structure. The electrode fixing groove can be a molded part made of UPVC (polyvinyl chloride non-foamed material) or PP (polypropylene) material.

[0040] In one specific embodiment of the present invention, the metal layer 22 has a porous structure, and the porosity of the metal layer 22 is 5-35%, which can be 5%, 10%, 15%, 20%, 25%, 30%, 35%, or any value within any two of these ranges. Setting the metal layer 22 as a porous structure can further improve the electrocatalytic effect, thereby further reducing the ammonia nitrogen content and COD of the effluent.

[0041] In one specific embodiment of the present invention, multiple sets of anode 2a, cathode 2b, and granular electrode 3 are correspondingly arranged, with the granular electrode 3 disposed between anode 2a and cathode 2b. Disposing the granular electrode 3 between anode 2a and cathode 2b polarizes the granular electrode, thereby further reducing the ammonia nitrogen content and COD of the effluent.

[0042] Preferably, the granular electrode 3 is made of graphite particles with a particle size of 1-20 mm. Studies have found that using graphite particles with a particle size of 1-20 mm as the granular electrode 3 can further reduce the ammonia nitrogen content and COD of the effluent. More preferably, the particle size of the graphite particles is 3-5 mm.

[0043] In one specific embodiment of the present invention, the reaction vessel 1 is further provided with a sludge discharge port and a water outlet. This facilitates the discharge of water and the discharge of sediment. Specifically, the sludge discharge port can be located at the bottom of the reaction vessel 1 or on a side near the bottom, and the water outlet can be located on a side near the bottom, or above the sludge discharge port.

[0044] In addition, the present invention also provides a method for treating high-concentration organic wastewater, the method comprising: injecting the high-concentration organic wastewater into the electrochemical device provided in any of the above specific embodiments to carry out an electrocatalytic reaction.

[0045] High-concentration organic wastewater refers to wastewater with a high concentration of organic matter, generally referring to wastewater with an organic matter concentration exceeding 2000 mg / L.

[0046] Preferably, the electrocatalytic reaction time is 20-40 min, which can be 20 min, 25 min, 30 min, 35 min, 40 min, or any value within any two of the above ranges. The voltage of the electrocatalytic reaction can be set according to the type of pollutants in the wastewater. In one specific embodiment of the present invention, the voltage of the electrocatalytic reaction is 4.5-5.3V, which can be 4.5V, 4.6V, 4.7V, 4.8V, 4.9V, 5V, 5.1V, 5.2V, 5.3V, or any value within any two of the above ranges.

[0047] According to a particularly preferred embodiment of the present invention, a method for treating organic wastewater is provided, comprising: like Figure 1 and Figure 2 As shown, the electrochemical device includes a reaction vessel 1, and an anode 2a, a cathode 2b, a granular electrode 3, and an aeration structure 4 disposed within the reaction vessel 1. The reaction vessel 1 is equipped with a sludge discharge port and a water outlet. Two to eight sets of anodes 2a, cathodes 2b, and granular electrodes 3 are arranged accordingly. The distance between the anodes 2a and cathodes 2b in adjacent sets is 5-15 cm. In each set, the distance between the anodes 2a and cathodes 2b is 5-15 cm. The granular electrode 3 fills the space between the anodes 2a and cathodes 2b. Both the anodes 2a and cathodes 2b include a first electrode layer 21, a second electrode layer 23, and a metal layer 22 disposed between the first electrode layer 21 and the second electrode layer 23. The length (i.e., the thickness of the electrode) of the cathode 2b is 3-30 mm, the width is 10-1000 mm, and the height is 10-1000 mm. The thickness ratio between the first electrode layer 21, the metal layer 22, and the second electrode layer 23 is 0.1-1:1:0.1-1. The first electrode layer 21 and the second electrode layer 23 are each independently a graphite layer or a titanium-ruthenium-iridium layer. The metal layer 22 is a mixture of metal a and metal b, where metal a is copper and metal b is selected from at least one of iron, nickel, and zinc. The copper content in the metal layer 22 is 2-20 wt%, and the porosity of the metal layer 22 is 5-35%. The particle size of the particulate electrode is 1-20 mm, and the particulate electrode fills the entire space between the cathode and the anode.

[0048] The wastewater to be treated is injected into the electrochemical device, the electrolysis voltage is 4.5-5.3V, and the ammonia nitrogen content and COD of the effluent are measured after 20-40 minutes of reaction.

[0049] When the above-mentioned device is used for organic wastewater treatment, the metal layer with the special structure described above can enhance the catalytic activity of the cathode and / or anode during the electrocatalytic process, further improving the electrocatalytic effect, significantly increasing the current efficiency and pollutant removal capacity within the reaction vessel, and thus further reducing the ammonia nitrogen content and COD in the effluent, achieving the goal of environmental protection. Its economic, social, and environmental benefits are significant. In particular, the effect of removing organic matter and ammonia nitrogen from low-concentration wastewater is significantly improved compared to traditional electrocatalysis. The addition of granular electrodes can also enhance the catalytic activity of the cathode and anode, further reducing the ammonia nitrogen content and COD in the effluent.

[0050] The present invention will be described in detail below through embodiments.

[0051] Example 1 The electrochemical device includes a reaction vessel 1 (100 mL), and an anode 2a, a cathode 2b, a granular electrode 3, and an aeration structure 4 disposed within the reaction vessel 1. The reaction vessel 1 is equipped with a sludge discharge port and a water outlet. Six sets of anodes 2a, cathodes 2b, and granular electrodes 3 are arranged accordingly, with a 2 cm spacing between anodes 2a and cathodes 2b in adjacent sets. In each set, the spacing between anodes 2a and cathodes 2b is 2 cm, and the granular electrodes 3 are filled between anodes 2a and cathodes 2b. Both anodes 2a and cathodes 2b include a first electrode layer 21 and a second electrode. The anode 2a and cathode 2b have a length (i.e., electrode thickness) of 5 mm, a width of 40 mm, and a height of 40 mm. The thickness ratio between the first electrode layer 21, the metal layer 22, and the second electrode layer 23 is 1:3:1. Both the first electrode layer 21 and the second electrode layer 23 are graphite layers. The metal layer 22 is a mixture of copper and iron, with a copper content of 12 wt% and a porosity of 15%. The particle size of the particulate electrode is 3 mm.

[0052] The wastewater to be treated is wastewater from a pharmaceutical and chemical company that has been treated by a wastewater treatment plant. The wastewater has a pH of 7.3, a TDS of 9000 mg / L, an ammonia nitrogen of 5 mg / L, a COD of 250 mg / L, and a chloride ion concentration of ≤3000 mg / L.

[0053] 100 mL of the above-mentioned wastewater to be treated was injected into the electrochemical device. The air aeration rate was set to 5 mL / min and the electrolysis voltage to 4.5 V. After reacting for 30 min, the ammonia nitrogen content and COD of the effluent were measured and recorded in Table 1.

[0054] Example 2 The electrochemical device differs from the electrochemical device in Example 1 in that the spacing between the anode 2a and cathode 2b in adjacent groups is 4 cm; in each group, the spacing between the anode 2a and cathode 2b is 4 cm, the length (i.e., the thickness of the electrode) of the anode 2a and cathode 2b is 5 mm, the width is 4 cm, and the height is 4 cm; the thickness ratio between the first electrode layer 21, the metal layer 22, and the second electrode layer 23 is 1:3:1; both the first electrode layer 21 and the second electrode layer 23 are titanium-ruthenium-iridium layers; the metal layer 22 is composed of a mixture of copper and zinc, and the copper content in the metal layer 22 is 25 wt%, and the porosity of the metal layer 22 is 25%; the particle size of the particulate electrode is 1 mm.

[0055] The wastewater to be treated is wastewater from a petrochemical enterprise that has been treated by a wastewater treatment plant. The wastewater has a pH of 6.7, a TDS of 2000 mg / L, an ammonia nitrogen of 45 mg / L, a COD of 420 mg / L, and a chloride ion concentration of ≤1000 mg / L.

[0056] 60 mL of the above-mentioned wastewater to be treated was injected into the electrochemical device. The air aeration rate was set to 10 mL / min and the electrolysis voltage to 5.3 V. After reacting for 30 min, the ammonia nitrogen content and COD of the effluent were measured and recorded in Table 1.

[0057] Example 3 The electrochemical device includes a reaction vessel 1 (100 mL), and an anode 2a, a cathode 2b, a granular electrode 3, and an aeration structure 4 disposed within the reaction vessel 1. The reaction vessel 1 is equipped with a sludge discharge port and a water outlet. Six sets of anodes 2a, cathodes 2b, and granular electrodes 3 are arranged accordingly, with a 2 cm spacing between anodes 2a and cathodes 2b in adjacent sets. In each set, the spacing between anodes 2a and cathodes 2b is 2 cm, and the granular electrode 3 fills the space between anodes 2a and cathodes 2b. Both anodes 2a and cathodes 2b include a first electrode layer 21 and a second electrode layer 22. The electrode layer 23 and the metal layer 22 disposed between the first electrode layer 21 and the second electrode layer 23; the anode 2a and the cathode 2b have a length (i.e., electrode thickness) of 5 mm, a width of 40 mm, and a height of 40 mm; the thickness ratio between the first electrode layer 21, the metal layer 22, and the second electrode layer 23 is 1:3:1; both the first electrode layer 21 and the second electrode layer 23 are graphite layers; the metal layer 22 contains copper and nickel, and the copper content in the metal layer 22 is 12 wt%; the porosity of the metal layer 22 is 15%; the particle size of the particulate electrode is 3 mm.

[0058] The wastewater to be treated is wastewater from a pharmaceutical and chemical company that has been treated by a wastewater treatment plant. The wastewater has a pH of 7.3, a TDS of 9000 mg / L, an ammonia nitrogen of 5 mg / L, a COD of 250 mg / L, and a chloride ion concentration of ≤3000 mg / L.

[0059] 100 mL of the above-mentioned wastewater to be treated was injected into the electrochemical device. The air aeration rate was set to 5 mL / min and the electrolysis voltage to 4.5 V. After reacting for 30 min, the ammonia nitrogen content and COD of the effluent were measured and recorded in Table 1.

[0060] Example 4 The electrochemical device differs from the electrochemical device in Example 1 in that the distance between the anode 2a and the cathode 2b in two adjacent groups is 5 cm; in each group, the distance between the anode 2a and the cathode 2b is 5 cm, the length (i.e. the thickness of the electrode) of the anode 2a and the cathode 2b is 2 mm, the width is 10 cm, and the height is 20 cm. The thickness ratio between the first electrode layer 21, the metal layer 22, and the second electrode layer 23 is 1:2:1. The first electrode layer 21 is a titanium-ruthenium-iridium layer, and the second electrode layer 23 is a titanium-ruthenium-iridium layer.

[0061] The wastewater to be treated is wastewater from a pharmaceutical and chemical company that has been treated by a wastewater treatment plant. The wastewater has a pH of 7.3, a TDS of 9000 mg / L, an ammonia nitrogen of 5 mg / L, a COD of 250 mg / L, and a chloride ion concentration of ≤3000 mg / L.

[0062] 2L of the above-mentioned wastewater to be treated was injected into the electrochemical device. The air aeration rate was set to 200mL / min and the electrolysis voltage to 4.5V. After reacting for 30min, the ammonia nitrogen content and COD of the effluent were measured and recorded in Table 1.

[0063] Example 5 The electrochemical device differs from the electrochemical device of Example 1 in that the metal layer 22 is composed of a mixture of copper and zinc, with a copper content of 45 wt% and a porosity of 20%.

[0064] The wastewater to be treated is wastewater from a pharmaceutical and chemical company that has been treated by a wastewater treatment plant. The wastewater has a pH of 7.3, a TDS of 9000 mg / L, an ammonia nitrogen of 5 mg / L, a COD of 250 mg / L, and a chloride ion concentration of ≤3000 mg / L.

[0065] 100 mL of the above-mentioned wastewater to be treated was injected into the electrochemical device. The air aeration rate was set to 20 mL / min and the electrolysis voltage to 4.5 V. After reacting for 30 min, the ammonia nitrogen content and COD of the effluent were measured and recorded in Table 1.

[0066] Example 6 The electrochemical device differs from the electrochemical device of Example 1 in that the metal layer 22 is composed of a mixture of copper, iron and zinc, with the copper content being 15 wt% and the iron content being 30 wt%.

[0067] The wastewater to be treated is wastewater from a pharmaceutical and chemical company that has been treated by a wastewater treatment plant. The wastewater has a pH of 7.3, a TDS of 9000 mg / L, an ammonia nitrogen of 5 mg / L, a COD of 250 mg / L, and a chloride ion concentration of ≤3000 mg / L.

[0068] 100 mL of the above-mentioned wastewater to be treated was injected into the electrochemical device. The air aeration rate was set to 5 mL / min and the electrolysis voltage to 4.5 V. After reacting for 30 min, the ammonia nitrogen content and COD of the effluent were measured and recorded in Table 1.

[0069] Example 7 The electrochemical device differs from the electrochemical device of Example 1 in that the metal layer 22 is composed of a mixture of copper and nickel, and the copper content in the metal layer 22 is 15 wt%.

[0070] The wastewater to be treated is wastewater from a pharmaceutical and chemical company that has been treated by a wastewater treatment plant. The wastewater has a pH of 7.3, a TDS of 9000 mg / L, an ammonia nitrogen of 5 mg / L, a COD of 250 mg / L, and a chloride ion concentration of ≤3000 mg / L.

[0071] 100 mL of the above-mentioned wastewater to be treated was injected into the electrochemical device. The air aeration rate was set to 5 mL / min and the electrolysis voltage to 4.5 V. After reacting for 30 min, the ammonia nitrogen content and COD of the effluent were measured and recorded in Table 1.

[0072] Example 8 The electrochemical device differs from the electrochemical device of Example 1 in that the cathode 2b does not contain a metal layer 22.

[0073] The wastewater to be treated is wastewater from a pharmaceutical and chemical company that has been treated by a wastewater treatment plant. The wastewater has a pH of 7.3, a TDS of 9000 mg / L, an ammonia nitrogen of 5 mg / L, a COD of 250 mg / L, and a chloride ion concentration of ≤3000 mg / L.

[0074] 100 mL of the above-mentioned wastewater to be treated was injected into the electrochemical device. The air aeration rate was set to 5 mL / min and the electrolysis voltage to 4.5 V. After reacting for 30 min, the ammonia nitrogen content and COD of the effluent were measured and recorded in Table 1.

[0075] Example 9 The electrochemical device differs from the electrochemical device of Example 1 in that the anode 2a does not contain a metal layer 22.

[0076] The wastewater to be treated is wastewater from a pharmaceutical and chemical company that has been treated by a wastewater treatment plant. The wastewater has a pH of 7.3, a TDS of 9000 mg / L, an ammonia nitrogen of 5 mg / L, a COD of 250 mg / L, and a chloride ion concentration of ≤3000 mg / L.

[0077] 100 mL of the above-mentioned wastewater to be treated was injected into the electrochemical device. The air aeration rate was set to 5 mL / min and the electrolysis voltage to 4.5 V. After reacting for 30 min, the ammonia nitrogen content and COD of the effluent were measured and recorded in Table 1.

[0078] Example 10 The electrochemical device differs from the electrochemical device in Example 1 in that the copper content in the metal layer 22 is 2wt%, and the porosity of the metal layer 22 is 15%.

[0079] The wastewater to be treated is wastewater from a pharmaceutical and chemical company that has been treated by a wastewater treatment plant. The wastewater has a pH of 7.3, a TDS of 9000 mg / L, an ammonia nitrogen of 5 mg / L, a COD of 250 mg / L, and a chloride ion concentration of ≤3000 mg / L.

[0080] 100 mL of the above-mentioned wastewater to be treated was injected into the electrochemical device. The air aeration rate was set to 5 mL / min and the electrolysis voltage to 4.5 V. After reacting for 30 min, the ammonia nitrogen content and COD of the effluent were measured and recorded in Table 1.

[0081] Example 11 The electrochemical device differs from the electrochemical device in Example 1 in that the copper content in the metal layer 22 is 30 wt%, and the porosity of the metal layer 22 is 15%.

[0082] The wastewater to be treated is wastewater from a pharmaceutical and chemical company that has been treated by a wastewater treatment plant. The wastewater has a pH of 7.3, a TDS of 9000 mg / L, an ammonia nitrogen of 5 mg / L, a COD of 250 mg / L, and a chloride ion concentration of ≤3000 mg / L.

[0083] 100 mL of the above-mentioned wastewater to be treated was injected into the electrochemical device. The air aeration rate was set to 5 mL / min and the electrolysis voltage to 4.5 V. After reacting for 30 min, the ammonia nitrogen content and COD of the effluent were measured and recorded in Table 1.

[0084] Comparative Example 1 The electrochemical device differs from the electrochemical device in Example 1 in that neither the anode 2a nor the cathode 2b contains a metal layer 22.

[0085] The wastewater to be treated is wastewater from a pharmaceutical and chemical company that has been treated by a wastewater treatment plant. The wastewater has a pH of 7.3, a TDS of 9000 mg / L, an ammonia nitrogen of 5 mg / L, a COD of 250 mg / L, and a chloride ion concentration of ≤3000 mg / L.

[0086] 100 mL of the above-mentioned wastewater to be treated was injected into the electrochemical device. The air aeration rate was set to 5 mL / min and the electrolysis voltage to 4.5 V. After reacting for 30 min, the ammonia nitrogen content and COD of the effluent were measured and recorded in Table 1.

[0087] Comparative Example 2 The electrochemical device differs from the electrochemical device in Example 2 in that neither the anode 2a nor the cathode 2b contains a metal layer 22.

[0088] The wastewater to be treated is wastewater from a petrochemical enterprise that has been treated by a wastewater treatment plant. The wastewater has a pH of 6.7, a TDS of 2000 mg / L, an ammonia nitrogen of 45 mg / L, a COD of 420 mg / L, and a chloride ion concentration of ≤1000 mg / L.

[0089] 60 mL of the above-mentioned wastewater to be treated was injected into the electrochemical device. The air aeration rate was set to 10 mL / min and the electrolysis voltage to 5.3 V. After reacting for 30 min, the ammonia nitrogen content and COD of the effluent were measured and recorded in Table 1.

[0090] Comparative Example 3 The electrochemical device differs from the electrochemical device of Example 1 in that the metal layer 22 contains only iron.

[0091] The wastewater to be treated is wastewater from a pharmaceutical and chemical company that has been treated by a wastewater treatment plant. The wastewater has a pH of 7.3, a TDS of 9000 mg / L, an ammonia nitrogen of 5 mg / L, a COD of 250 mg / L, and a chloride ion concentration of ≤3000 mg / L.

[0092] 100 mL of the above-mentioned wastewater to be treated was injected into the electrochemical device. The air aeration rate was set to 5 mL / min and the electrolysis voltage to 4.5 V. After reacting for 30 min, the ammonia nitrogen content and COD of the effluent were measured and recorded in Table 1.

[0093] Comparative Example 4 The electrochemical device differs from the electrochemical device of Example 4 in that it does not contain metal layer 22.

[0094] The wastewater to be treated is wastewater from a pharmaceutical and chemical company that has been treated by a wastewater treatment plant. The wastewater has a pH of 7.3, a TDS of 9000 mg / L, an ammonia nitrogen of 5 mg / L, a COD of 250 mg / L, and a chloride ion concentration of ≤3000 mg / L.

[0095] 2L of the above-mentioned wastewater to be treated was injected into the electrochemical device. The air aeration rate was set to 200mL / min and the electrolysis voltage to 4.5V. After reacting for 30min, the ammonia nitrogen content and COD of the effluent were measured and recorded in Table 1.

[0096] Comparative Example 5 The electrochemical device differs from the electrochemical device in Example 1 in that the metal layer 22 contains only copper, and the metal layer 22 has two layers, with the first electrode layer 21 and the second electrode layer 23 disposed between the two metal layers 22.

[0097] The wastewater to be treated is wastewater from a pharmaceutical and chemical company that has been treated by a wastewater treatment plant. The wastewater has a pH of 7.3, a TDS of 9000 mg / L, an ammonia nitrogen of 5 mg / L, a COD of 250 mg / L, and a chloride ion concentration of ≤3000 mg / L.

[0098] 100 mL of the above-mentioned wastewater to be treated was injected into the electrochemical device. The air aeration rate was set to 5 mL / min and the electrolysis voltage to 4.5 V. After reacting for 30 min, the ammonia nitrogen content and COD of the effluent were measured and recorded in Table 1.

[0099] Table 1

[0100] As can be seen from the results in Table 1, the ammonia nitrogen content and COD of the wastewater treated in the example were lower than those in the comparative example, indicating that the electrochemical device provided by the present invention has a better treatment effect on wastewater.

[0101] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An electrochemical device, characterized in that, The electrochemical device includes a reaction vessel (1) and an anode (2a), a cathode (2b) and a particulate electrode (3) disposed within the reaction vessel (1). At least one of the anode (2a) and the cathode (2b) includes a first electrode layer (21), a second electrode layer (23) and a metal layer (22) disposed between the first electrode layer (21) and the second electrode layer (23). The metal layer (22) contains metal a and metal b, where metal a is copper and metal b is selected from at least one of iron, nickel and zinc.

2. The electrochemical device according to claim 1, characterized in that, Both the anode (2a) and the cathode (2b) include a first electrode layer (21), a second electrode layer (23), and a metal layer (22) disposed between the first electrode layer (21) and the second electrode layer (23).

3. The electrochemical device according to claim 1, characterized in that, In the metal layer (22), the content of metal a is 2-30 wt%, preferably 10-25 wt%.

4. The electrochemical device according to any one of claims 1 to 3, characterized in that, The thickness ratio of the first electrode layer (21), the metal layer (22) and the second electrode layer (23) is 0.1-1:1:0.1-1.

5. The electrochemical device according to any one of claims 1 to 3, characterized in that, The first electrode layer (21) and the second electrode layer (23) are each independently a graphite layer or a titanium-ruthenium-iridium alloy layer.

6. The electrochemical device according to any one of claims 1 to 3, characterized in that, The electrochemical device also includes an aeration structure (4) disposed inside the reaction vessel (1).

7. The electrochemical device according to any one of claims 1 to 3, characterized in that, The metal layer (22) has a porous structure and the porosity of the metal layer (22) is 5-35%.

8. The electrochemical device according to any one of claims 1 to 3, characterized in that, Multiple sets of anode (2a), cathode (2b) and particle electrode (3) are provided respectively, and the particle electrode (3) is disposed between the anode (2a) and the cathode (2b).

9. The electrochemical device according to any one of claims 1 to 3, characterized in that, The particulate electrode (3) is a graphite particle with a particle size of 1-20 mm.

10. A method for treating high-concentration organic wastewater, characterized in that, The treatment method includes: injecting high-concentration organic wastewater into the electrochemical device according to any one of claims 1 to 9 to carry out an electrocatalytic reaction; Preferably, the electrocatalytic reaction takes 20-40 minutes.

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