Wastewater treatment system and integrated device based on multi-stage electrochemical cyclic oxidation

Abstract

This invention discloses a wastewater treatment system based on multi-stage electrochemical cyclic oxidation, comprising: a primary cyclic oxidation system for preliminary oxidation pretreatment of wastewater, the primary cyclic oxidation system including a circulating water tank forming a loop and a first electrochemical reaction unit; a secondary cyclic oxidation system for deep oxidation treatment of wastewater, the secondary cyclic oxidation system including a deep oxidation unit forming a loop and a second electrochemical reaction unit; a sedimentation system for sedimentation and sludge-water separation of wastewater; and a switching loop system for switching the connection between the primary and secondary cyclic oxidation systems and the sedimentation system. This invention employs a two-stage cyclic oxidation system for the electrolytic oxidation of wastewater, and both stages can be controlled independently. The treatment effect on wastewater can be altered by adjusting the current of the DC power supply, thereby ensuring stable effluent compliance.

Description

Technical Field

[0001] This invention belongs to the field of environmental water treatment technology, specifically relating to a wastewater treatment system and integrated device based on multi-stage electrochemical cyclic oxidation. Background Technology

[0002] Organic wastewater is notoriously difficult to degrade, making it difficult for traditional water treatment processes to completely remove it from the aquatic environment, often resulting in severe environmental pollution. Therefore, electrochemical oxidation is frequently used to remove organic wastewater. This method is characterized by its high efficiency and environmental friendliness. It utilizes the principle of electrolysis, avoiding the secondary pollution problems caused by the addition of reagents required in chemical oxidation methods. Furthermore, the reaction conditions are mild and the operation is highly controllable. The electrochemical reaction occurs at the surfaces of the anode and cathode. The anode uses its strong oxidizing power to catalyze the oxidation of organic pollutants; the cathode reduces Fe in situ. 3+ Electrochemical oxidation of organic pollutants occurs through electro-Fenton oxidation with O2. The development of electrode materials and the design of electrocatalytic reactors are key areas of research for improving the efficiency of electrochemical oxidation.

[0003] In existing technologies, plate electrodes are generally used. However, plate electrodes have poor mass transfer efficiency for surface contaminants and low electrocatalytic efficiency. Furthermore, the cathode electro-Fenton requires an external oxygen source, resulting in low oxygen utilization. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the present invention aims to provide a wastewater treatment system and integrated device based on multi-stage electrochemical cyclic oxidation, which aims to solve the problems of poor mass transfer of pollutants on the surface of plate electrodes, low electrocatalytic efficiency, and low oxygen utilization rate of cathode Fenton electrodes.

[0005] This invention is achieved through the following technical solution:

[0006] A wastewater treatment system based on multi-stage electrochemical cyclic oxidation includes,

[0007] A primary circulating oxidation system is used for preliminary oxidation pretreatment of wastewater. The primary circulating oxidation system includes a circulating water tank forming a loop and a first electrochemical reaction unit.

[0008] A two-stage circulating oxidation system is used for deep oxidation treatment of wastewater. The two-stage circulating oxidation system includes a deep oxidation unit that forms a loop and a second electrochemical reaction unit.

[0009] Sedimentation systems are used for the sedimentation of wastewater and the separation of sludge and water.

[0010] The switching loop system is used to switch the connection between the primary circulating oxidation system and the secondary circulating oxidation system and precipitation system.

[0011] To optimize the above technical solution, the specific measures also include:

[0012] Furthermore, the first electrochemical reaction unit includes multiple sets of reaction electrodes and a first DC power supply. A reaction tank is provided outside the multiple sets of reaction electrodes, and the multiple sets of reaction electrodes are distributed at intervals inside the reaction tank. The reaction tank is provided with a circulating water inlet, a circulating water outlet and a drain outlet. The circulating water inlet and the circulating water outlet are both connected to a circulating water tank, and the drain outlet is connected to the reaction electrodes and the switching circuit system.

[0013] Furthermore, each set of reaction electrodes includes an anode electrode and a cathode electrode, with the cathode electrode sleeved outside the anode electrode, and the first DC power supply connected to the anode electrode and the cathode electrode.

[0014] Furthermore, the sedimentation system includes a sedimentation tank and a product water tank connected in sequence by pipelines, and the sedimentation tank is connected to the second electrochemical reaction unit and the switching loop system.

[0015] Furthermore, the switching loop system includes a water quality monitor, a first solenoid valve, and a second solenoid valve. The first and second solenoid valves are connected in parallel, and both the first and second solenoid valves are connected in series with the water quality monitor. The water quality monitor is connected to the drain outlet of the first electrochemical reaction unit, the first solenoid valve is connected to the deep oxidation unit, and the second solenoid valve is connected to the sedimentation tank.

[0016] Furthermore, the first solenoid valve and the water quality monitor constitute a first processing circuit, and the second solenoid valve and the water quality monitor constitute a second processing circuit.

[0017] Furthermore, the water quality monitoring instrument includes a COD monitor and an NH3-N monitor.

[0018] Furthermore, when the data value detected by the water quality monitor is lower than the set value, the first processing loop is switched; when the data value detected by the water quality monitor exceeds the set value, the second processing loop is switched.

[0019] Furthermore, the second electrochemical reaction unit has the same structure as the first electrochemical reaction unit.

[0020] Furthermore, the deep oxidation unit includes an oxidation tank, an iron electrode, and a second DC power supply. The iron electrode is installed inside the deep oxidation tank, and the second DC power supply is connected to the iron electrode.

[0021] In another aspect, the present invention provides an integrated wastewater treatment device based on multi-stage electrochemical cyclic oxidation, comprising a square tank, a circulating water tank, a first electrochemical reaction unit, a deep oxidation unit, and a second electrochemical reaction unit. The circulating water tank, the first electrochemical reaction unit, the deep oxidation unit, and the second electrochemical reaction unit are all disposed within the tank. An aeration system is provided at the bottom of the deep oxidation unit. The circulating water tank and the first electrochemical reaction unit form a loop through pipelines. The first electrochemical reaction unit and the deep oxidation unit are connected by a unidirectional pipeline. The deep oxidation unit and the second electrochemical reaction unit form a loop through pipelines. The circulating water tank is provided with a raw water inlet, and the second electrochemical reaction unit is provided with a discharge outlet.

[0022] The beneficial effects of this invention are:

[0023] Compared with the prior art, the wastewater treatment system based on multi-stage electrochemical cyclic oxidation of the present invention adopts a two-stage cyclic oxidation system for the electrolytic oxidation of wastewater. The first-stage cyclic oxidation system can work alone, or the first-stage cyclic oxidation system and the second-stage cyclic oxidation system can work in series. Moreover, the two-stage cyclic oxidation systems can be controlled independently. The treatment effect on wastewater can be changed by adjusting the current of the DC power supply, thereby ensuring that the effluent meets the standards stably.

[0024] Meanwhile, in the deep oxidation unit, ferrous ions are provided by a DC power supply in conjunction with an iron electrode. Hydrogen peroxide generated by electrochemical oxidation can be used to degrade pollutants, and then ferrous ions are removed in the sedimentation tank by adding alkali.

[0025] This invention discloses an integrated wastewater treatment device based on multi-stage electrochemical cyclic oxidation. It employs an integrated tank structure, resulting in a small footprint. Furthermore, it can determine whether to activate the deep oxidation tank based on the quality of the incoming raw water. The deep oxidation tank is activated when the water contains recalcitrant organic matter, and oxygen levels are increased through aeration. This increased oxygen content generates more H2O2, which reacts with Fe in the deep oxidation tank. 2+ It can form a Fenton oxidation system, thereby enabling the ring-opening and bond-breaking of recalcitrant macromolecular organic compounds, thus increasing the processing efficiency of the subsequent second electrochemical reaction unit. Attached Figure Description

[0026] Figure 1 This is a flowchart of a wastewater treatment system based on multi-stage electrochemical cyclic oxidation according to the present invention.

[0027] Figure 2 yes Figure 1 A schematic diagram of a local structure.

[0028] Figure 3 This is a schematic diagram of the structure of an integrated wastewater treatment device based on multi-stage electrochemical cyclic oxidation according to the present invention.

[0029] Figure 4 yes Figure 3 Schematic diagram of the middle section.

[0030] The attached diagram is labeled as follows: Primary circulating oxidation system 1, circulating water tank 11, first electrochemical reaction unit 12, reaction electrode 121, first DC power supply 122, reaction tank 123, secondary circulating oxidation system 2, deep oxidation unit 21, oxidation pool 211, iron electrode 212, second DC power supply 213, second electrochemical reaction unit 22, sedimentation system 3, sedimentation pool 31, product water tank 32, switching circuit system 4, water quality monitor 41, first solenoid valve 42, second solenoid valve 43, circulating water inlet A, circulating water outlet B, drain outlet C, first water pump 50, second water pump 60, aeration system 70. Detailed Implementation

[0031] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0032] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0033] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0034] Example 1

[0035] Reference Figure 1 This embodiment provides a wastewater treatment system based on multi-stage electrochemical cyclic oxidation, including a first cyclic oxidation system 1, a second cyclic oxidation system 2, a sedimentation system 3, and a switching loop system 4.

[0036] The primary circulating oxidation system 1 is used for preliminary oxidation pretreatment of wastewater. The primary circulating oxidation system 1 includes a circulating water tank 11 that forms a loop and a first electrochemical reaction unit 12.

[0037] The circulating water tank 11 is used to receive and store sewage, and at the same time participates in the circulation process of the first electrochemical reaction unit 12.

[0038] The first electrochemical reaction unit 12 includes multiple sets of reaction electrodes 121 and a first DC power supply 122. A reaction tank 123 is disposed outside the multiple sets of reaction electrodes 121. The multiple sets of reaction electrodes 121 are spaced apart inside the reaction tank 123. The reaction tank 123 has a circulation inlet A, a circulation outlet B, and a drain outlet C. The circulation inlet A and circulation outlet B are both connected to the circulation water tank 11, and the drain outlet C is connected to the reaction electrodes 121 and the switching circuit system 4. Each set of reaction electrodes 121 includes an anode electrode and a cathode electrode. The cathode electrode is sleeved outside the anode electrode. The first DC power supply 122 is connected to the anode electrode and the cathode electrode.

[0039] The working process of the first circulating oxidation system 1 is as follows: After the sewage enters the circulating water tank 11, it circulates between the circulating water tank 11 and the reaction tank 123. The organic matter in the sewage is degraded by the electrolytic oxidation reaction of the anode electrode and the cathode electrode. The anode electrode is a Ti-RuO2 electrode and the cathode electrode is a stainless steel electrode.

[0040] The secondary circulating oxidation system 2 is used for deep oxidation treatment of wastewater. The secondary circulating oxidation system 2 includes a deep oxidation unit 21 that forms a loop and a second electrochemical reaction unit 22.

[0041] The deep oxidation unit 21 includes an oxidation tank 211, an iron electrode 212, and a second DC power supply 213. The iron electrode 212 is installed inside the deep oxidation tank 211, and the second DC power supply 213 is connected to the iron electrode 212. The second DC power supply 213 provides current, causing the iron electrode 212 to generate ferrous ions. These ferrous ions react with hydrogen peroxide produced during the primary circulating oxidation process to produce a Fenton oxidation reaction in the second electrochemical reaction unit 22, thereby degrading the organic matter in the wastewater and further improving the treatment efficiency of organic matter.

[0042] The second electrochemical reaction unit 22 has the same structure as the first electrochemical reaction unit 12. The second electrochemical reaction unit 22 includes multiple sets of reaction electrodes 121 and a first DC power supply 122. A reaction tank 123 is set outside the multiple sets of reaction electrodes 121. The multiple sets of reaction electrodes 121 are distributed at intervals inside the reaction tank 123. The reaction tank 123 has a circulation inlet A, a circulation outlet B, and a drain outlet C. The circulation inlet A and circulation outlet B are both connected to the oxidation tank 211, and the drain outlet C is connected to the reaction electrodes 121 and the precipitation system 3. Each set of reaction electrodes 121 includes an anode electrode and a cathode electrode. The anode electrode is sleeved on the outside of the cathode electrode. The first DC power supply 122 is connected to the anode electrode and the cathode electrode.

[0043] Sedimentation system 3 is used for sedimentation of wastewater and separation of sludge and water;

[0044] The sedimentation system 3 includes a sedimentation tank 31 and a product water tank 32 connected in sequence by pipelines. The sedimentation tank 31 is connected to the second electrochemical reaction unit 22 and the switching loop system 4. A dosing point is provided on the pipeline between the sedimentation tank 31 and the second electrochemical reaction unit 22 for adding alkali to bring the pH value to 8-9, so that ferrous ions are precipitated and removed in the sedimentation tank 31.

[0045] Switching loop system 4 is used to switch the connection between primary circulating oxidation system 1 and secondary circulating oxidation system 2 and precipitation system 3.

[0046] The switching loop system 4 includes a water quality monitor 4141, a first solenoid valve 42, and a second solenoid valve 43. The first solenoid valve 42 and the second solenoid valve 43 are connected in parallel, and both the first solenoid valve 42 and the second solenoid valve 43 are connected in series with the water quality monitor 4141. The water quality monitor 4141 is connected to the drain outlet of the first electrochemical reaction unit 12, the first solenoid valve 42 is connected to the deep oxidation unit 21, and the second solenoid valve 43 is connected to the sedimentation tank 31. The water quality monitor 41 includes a COD monitor and an NH3-N monitor.

[0047] The first solenoid valve 42 and the water quality monitor 41 constitute the first processing loop, and the second solenoid valve 43 and the water quality monitor 4141 constitute the second processing loop. When the data value detected by the water quality monitor 41 is greater than the set value, the first processing loop is switched; when the data value detected by the water quality monitor 41 is less than the set value, the second processing loop is switched.

[0048] Example 2

[0049] Reference Figures 1-3 This embodiment provides an integrated wastewater treatment device based on multi-stage electrochemical cyclic oxidation, which achieves an integrated layout, occupies a small area, and allows for the selection of appropriate treatment modes according to water quality.

[0050] An integrated wastewater treatment device based on multi-stage electrochemical cyclic oxidation includes a square tank, a circulating water tank 11, a first electrochemical reaction unit 12, a deep oxidation unit 21, and a second electrochemical reaction unit 22. The circulating water tank 11, the first electrochemical reaction unit 12, the deep oxidation unit 21, and the second electrochemical reaction unit 22 are all located within the tank. An aeration system 70 is installed at the bottom of the deep oxidation unit 21. The circulating water tank 11 and the first electrochemical reaction unit 12 form a loop through pipelines. The first electrochemical reaction unit 12 and the deep oxidation unit 21 are connected by a unidirectional pipeline. The deep oxidation unit 21 and the second electrochemical reaction unit 22 form a loop through pipelines. The circulating water tank 11 is provided with a raw water inlet, and the second electrochemical reaction unit 22 is provided with a discharge outlet.

[0051] The aeration system 70 uses aeration pipes connected to an external air pump to introduce air into the deep oxidation tank, increasing the oxygen content in the water within the deep oxidation unit. This increased oxygen content, under the action of the iron electrodes, generates more H2O2. The H2O2 then reacts with the Fe in the deep oxidation tank... 2+ It can form a Fenton oxidation system, thereby enabling the ring-opening and bond-breaking of recalcitrant macromolecular organic compounds, thus increasing the processing efficiency of the subsequent second electrochemical reaction unit.

[0052] During operation, the wastewater from the circulating water tank 11 is first pumped into the first electrochemical reaction unit 12 by the first water pump 50 outside the tank. Then, the wastewater treated by the first electrochemical reaction unit 12 inside the tank is diverted. Part of it is fed back into the circulating water tank 11 for circulating reaction treatment, while the other part flows into the deep oxidation unit 21 through an external pipeline. After being reacted in the deep oxidation unit 21, the wastewater is pumped into the second electrochemical reaction unit 22 by the second water pump 60 outside the tank. The wastewater treated by the second electrochemical reaction unit 22 is diverted. Part of it is output from the second electrochemical reaction unit 22, while the other part is fed back into the deep oxidation unit 21 to participate in the circulating reaction.

[0053] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A wastewater treatment system based on multi-stage electrochemical cyclic oxidation, characterized in that: include, A primary circulating oxidation system is used for preliminary oxidation pretreatment of wastewater, comprising a circulating water tank forming a loop and a first electrochemical reaction unit; a secondary circulating oxidation system is used for deep oxidation treatment of wastewater, comprising a deep oxidation unit forming a loop and a second electrochemical reaction unit; a sedimentation system is used for sedimentation and sludge-water separation of wastewater; a switching loop system is used to switch the connection between the primary circulating oxidation system, the secondary circulating oxidation system, and the sedimentation system, comprising a water quality monitor, a first solenoid valve, and a second solenoid valve connected in parallel. Both the first and second solenoid valves are connected in series with a water quality monitor. The water quality monitor is connected to the drain outlet of the first electrochemical reaction unit. The first solenoid valve is connected to the deep oxidation unit, and the second solenoid valve is connected to the sedimentation tank. The first solenoid valve and the water quality monitor constitute a first processing loop, and the second solenoid valve and the water quality monitor constitute a second processing loop. When the data value detected by the water quality monitor is lower than the set value, the first processing loop is switched. When the data value detected by the water quality monitor exceeds the set value, the second processing loop is switched. The deep oxidation unit includes an oxidation tank, an iron electrode, and a second DC power supply. The iron electrode is installed in the deep oxidation tank, and the second DC power supply is connected to the iron electrode.

2. The wastewater treatment system based on multi-stage electrochemical cyclic oxidation according to claim 1, characterized in that: The first electrochemical reaction unit includes multiple sets of reaction electrodes and a first DC power supply. A reaction tank is provided outside the multiple sets of reaction electrodes. The multiple sets of reaction electrodes are distributed at intervals inside the reaction tank. The reaction tank is provided with a circulating water inlet, a circulating water outlet and a drain outlet. The circulating water inlet and the circulating water outlet are both connected to a circulating water tank. The drain outlet is connected to the reaction electrodes and the switching circuit system.

3. The wastewater treatment system based on multi-stage electrochemical cyclic oxidation according to claim 2, characterized in that: Each set of reaction electrodes includes an anode electrode and a cathode electrode, with the cathode electrode sleeved outside the anode electrode, and the first DC power supply connected to the anode electrode and the cathode electrode.

4. The wastewater treatment system based on multi-stage electrochemical cyclic oxidation according to claim 1, characterized in that: The sedimentation system includes a sedimentation tank and a product water tank connected in sequence by pipelines. The sedimentation tank is connected to the second electrochemical reaction unit and the switching loop system.

5. A wastewater treatment system based on multi-stage electrochemical cyclic oxidation according to claim 2, characterized in that: The second electrochemical reaction unit has the same structure as the first electrochemical reaction unit.

6. An integrated device employing the wastewater treatment system based on multi-stage electrochemical cyclic oxidation as described in claim 1, characterized in that: The device includes a square pool, a circulating water tank, a first electrochemical reaction unit, a deep oxidation unit, and a second electrochemical reaction unit. All three units are housed within the pool. An aeration system is installed at the bottom of the deep oxidation unit. The circulating water tank and the first electrochemical reaction unit form a circuit via pipelines. The first electrochemical reaction unit and the deep oxidation unit are connected by a unidirectional pipeline. The deep oxidation unit and the second electrochemical reaction unit also form a circuit via pipelines. The circulating water tank has a raw water inlet, and the second electrochemical reaction unit has a discharge outlet.

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