Electroplating chromium-containing wastewater treatment device and electroplating chromium-containing wastewater treatment method

Abstract

The invention discloses an electroplating chromium-containing wastewater treatment device and an electroplating chromium-containing wastewater treatment method, and belongs to the technical field of electroplating wastewater treatment. The electroplating chromium-containing wastewater to be treated flows into a cathode chamber in a reaction treatment unit from a water inlet, hexavalent chromium in the electroplating chromium-containing wastewater is converted into trivalent chromium through electrons near a carbon-based cathode, and then the trivalent chromium flows into an anode chamber in the reaction treatment unit; the dissolving-out type iron anode loses electrons to generate ferrous ions, residual hexavalent chromium in the electroplating chromium-containing wastewater is reduced into trivalent chromium through the ferrous ions, and the wastewater sequentially passing through the cathode chamber and the anode chamber flows out of the water outlet; wherein electron movement is generated between the cathode chamber and the anode chamber through the conductive diaphragm, so that an electrode and a medicine do not need to be additionally added when the device is used for treating the wastewater, and the wastewater treatment cost is reduced.

Description

Technical Field

[0001] This application relates to the technical field of electroplating chromium-containing wastewater treatment, and particularly to an electroplating chromium-containing wastewater treatment device and an electroplating chromium-containing wastewater treatment method. Background Art

[0002] Chromium widely exists in manufacturing industries such as leather making, stainless steel, automobiles, electronics, machine tools, and daily hardware. Electroplating is one of the most important industrial applications of chromium. The chromium-containing wastewater generated during the electroplating process mainly contains highly toxic hexavalent chromium, which has strong oxidizing properties, accumulativeness, and carcinogenicity, posing a serious threat to the environment and human health.

[0003] Currently, the methods for treating chromium-containing wastewater mainly include: chemical reduction method and electrochemical method. Among them, the chemical reduction method mainly uses sulfite or other reducing agents to reduce hexavalent chromium in the sewage to trivalent chromium, and then adjusts the pH value to precipitate trivalent chromium to achieve the purpose of removing chromium. Among them, the principle of the electrochemical method is that under the action of the electric field force, hexavalent chromium moves towards the cathode surface. At the interface between the electrode material and the solution, hexavalent chromium obtains electrons and is reduced. Through this electrochemical reaction, the removal of hexavalent chromium is achieved.

[0004] However, the chemical reduction method has a high reagent cost, and for the electrochemical method to treat hexavalent chromium, continuous power supply is required, the energy consumption is large, and the electrode dissolution is significant, and the required cost is also relatively high. Therefore, there is an urgent need to develop a low-cost and environmentally friendly chromium-containing wastewater treatment technology. Summary of the Invention

[0005] The main purpose of this application is to provide an electroplating chromium-containing wastewater treatment device and an electroplating chromium-containing wastewater treatment method, aiming to solve the technical problem of high cost in chromium-containing wastewater treatment technology.

[0006] To achieve the above purpose, this application provides an electroplating chromium-containing wastewater treatment device, which includes a reaction treatment unit, a conductive diaphragm, a carbon-based cathode, a dissolving iron anode, a water inlet, and a water outlet; The reaction treatment unit is separated into a cathode chamber and an anode chamber by the conductive diaphragm, and forms an ion-conducting and hexavalent chromium-isolated concentration gradient system based on the cathode chamber and the anode chamber; The carbon-based cathode is arranged in the cathode chamber and is distributed in several parallel layers in the cathode chamber. A high specific surface area catalytic material is coated on the surface of each layer of the carbon-based cathode. Among them, the carbon-based cathode is selected from non-dissolving materials such as carbon felt, granular activated carbon, or porous graphite; The dissolving iron anode is arranged in the anode chamber and is distributed in several parallel layers in the anode chamber. Each layer of the dissolving iron anode has a low specific surface area and a replaceable structure; The water inlet and the water outlet form a continuous flow channel, and the water flow direction in the continuous flow channel is to sequentially pass through the cathode chamber and the anode chamber; The device is also equipped with an electrode spacing adjustment mechanism and a flow channel control system. The electrode spacing adjustment mechanism is used to adjust the spacing between any adjacent electrodes in the treatment unit, and the flow channel control system is used to control the flow rate of the wastewater in the continuous flow channel.

[0007] In one embodiment, the conductive diaphragm is an asbestos diaphragm or a cation exchange membrane.

[0008] In one embodiment, the surface catalytic material of the carbon-based cathode adopts a composite oxide for providing an active reaction site.

[0009] In one embodiment, the dissolution-type iron anode is configured with a mechanical replacement mechanism, and the mechanical replacement mechanism is used to trigger automatic replacement when the anode consumption reaches a preset value.

[0010] In one embodiment, the flow channel control system includes a baffle plate group and a flow guide grid, so that the wastewater forms a turbulent flow in the cathode chamber and a laminar flow in the anode chamber.

[0011] In one embodiment, the device further includes a concentration gradient monitoring module, which is used to detect the concentration difference of hexavalent chromium between the cathode chamber and the anode chamber in real time, and feedback adjustment information to the electrode spacing adjustment mechanism and the flow channel control system to adaptively adjust the electrode spacing and the flow rate.

[0012] This application provides a method for treating electroplating chromium-containing wastewater, which is applied to an electroplating chromium-containing wastewater treatment device. The device includes a reaction treatment unit, a conductive diaphragm, a carbon-based cathode, a dissolution-type iron anode, a water inlet and a water outlet. The method includes the following steps: Flow the electroplating chromium-containing wastewater to be treated from the water inlet into the cathode chamber in the reaction treatment unit. Near the carbon-based cathode, the hexavalent chromium in the electroplating chromium-containing wastewater gains electrons and is converted into trivalent chromium, and then flows into the anode chamber in the reaction treatment unit; The dissolution-type iron anode loses electrons to generate ferrous ions, and the ferrous ions are used to reduce the remaining hexavalent chromium in the electroplating chromium-containing wastewater into trivalent chromium, and the wastewater that sequentially passes through the cathode chamber and the anode chamber flows out from the water outlet; wherein, electron movement occurs between the cathode chamber and the anode chamber through the conductive diaphragm; Adjust the acidity and alkalinity of the outflowing wastewater for flocculation, and perform mud-water separation and concentration after adjusting the acidity and alkalinity for flocculation.

[0013] In one embodiment, the separated sludge is subjected to microwave pyrolysis treatment to generate iron-chromium composite oxide for the regeneration of the catalytic material of the carbon-based cathode.

[0014] One or more technical solutions proposed in this application have at least the following technical effects: Applied to an electroplating chromium-containing wastewater treatment device, the device includes a reaction treatment unit, a conductive diaphragm, a carbon-based cathode, a leaching-type iron anode, a water inlet and a water outlet. The electroplating chromium-containing wastewater to be treated flows into the cathode chamber in the reaction treatment unit from the water inlet, and near the carbon-based cathode, hexavalent chromium in the electroplating chromium-containing wastewater gains electrons and is converted into trivalent chromium, and then flows into the anode chamber in the reaction treatment unit; ferrous ions are generated by the leaching-type iron anode losing electrons, and the remaining hexavalent chromium in the electroplating chromium-containing wastewater is reduced to trivalent chromium by the ferrous ions, and the wastewater flowing through the cathode chamber and the anode chamber in sequence flows out from the water outlet; wherein, electron movement is generated between the cathode chamber and the anode chamber through the conductive diaphragm; the outflowing wastewater is subjected to acid-base adjustment and flocculation, and after acid-base adjustment and flocculation, solid-liquid separation and concentration are carried out on it. Thus, under the treatment effect of the carbon-based anode, conductive diaphragm, and leaching-type iron anode of the electroplating chromium-containing wastewater treatment device, without additional chemical agents being added or continuous power supply being required, only relying on the spontaneous electron movement between the cathode, anode, and conductive diaphragm, the effects of obtaining electrons by hexavalent chromium and converting it into trivalent chromium in the cathode chamber and using ferrous ions to reduce hexavalent chromium to trivalent chromium in the anode chamber can be achieved, and in the dual treatment scheme, the content of hexavalent chromium in the electroplating chromium-containing wastewater is effectively reduced, thereby achieving the effect of treating electroplating chromium-containing wastewater at low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with this application, and are used together with the specification to explain the principles of this application.

[0016] In order to more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a simplified structural schematic diagram of the electroplating chromium-containing wastewater treatment device of this application; Figure 2 It is a schematic flow diagram provided by an embodiment of the electroplating chromium-containing wastewater treatment method of this application; Figure 3 It is a schematic overall process flow diagram of the electroplating chromium-containing wastewater treatment device and the electroplating chromium-containing wastewater treatment method of this application.

[0018] The realization of the purpose of this application, functional characteristics, and advantages will be further described with reference to the embodiments and the drawings. Detailed implementation manners

[0019] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0020] Based on the above problems, an electroplating chromium-containing wastewater treatment device is provided in an embodiment of the present application. Refer to Figure 1 , Figure 1 which is a simplified structural schematic diagram of the electroplating chromium-containing wastewater treatment device of the present application.

[0021] In this embodiment, an electroplating chromium-containing wastewater treatment device includes a reaction treatment unit, a conductive diaphragm, a carbon-based cathode, a dissolving iron anode, a water inlet and a water outlet; The reaction treatment unit is separated into a cathode chamber and an anode chamber by the conductive diaphragm, and an ion conduction and a concentration gradient system for hexavalent chromium isolation are formed based on the cathode chamber and the anode chamber; The carbon-based cathode is arranged in the cathode chamber and is distributed in parallel in several layers in the cathode chamber. A high specific surface area catalytic material is coated on the surface of each layer of the carbon-based cathode. Among them, the carbon-based cathode is selected from non-dissolving materials such as carbon felt, granular activated carbon or porous graphite; The dissolving iron anode is arranged in the anode chamber and is distributed in parallel in several layers in the anode chamber. Each layer of the dissolving iron anode has a low specific surface area and a replaceable structure; The water inlet and the water outlet form a continuous flow channel, and the water flow direction in the continuous flow channel is to pass through the cathode chamber and the anode chamber in sequence; The device is also equipped with an electrode spacing adjusting mechanism and a flow channel control system. The electrode spacing adjusting mechanism is used to adjust the spacing between any adjacent electrodes in the treatment unit, and the flow channel control system is used to control the wastewater flow rate in the continuous flow channel.

[0022] That is, in this embodiment, refer to Figure 1 , a treatment unit is provided, and in this treatment unit, a left and a right cathode chamber and anode chamber are divided by a conductive diaphragm. Among them, a water inlet is arranged on one side of the cathode chamber, and a water outlet is arranged on one side of the anode chamber.

[0023] Among them, a carbon-based cathode is arranged in the cathode chamber. A high specific surface area catalytic material is coated on the surface of the carbon-based cathode. Specifically, non-dissolving materials such as carbon felt, granular activated carbon or porous graphite are used, and in a parallel distribution manner, the electroplating chromium-containing wastewater is in contact with the carbon-based cathode with the largest contact area, and corresponding electrons are obtained through the carbon-based cathode, so that hexavalent chromium is converted into trivalent chromium. Among them, the purpose of the high specific surface area catalytic material is to provide an active reaction site, which helps the conversion process of hexavalent chromium.

[0024] Among them, a dissolving iron anode is arranged in the anode chamber. The dissolving iron anode is also distributed in parallel in the anode chamber to ensure its contact area with the electroplating chromium-containing wastewater. Since it is a dissolving anode, a certain replaceable structure will be set during use. The specific structural features are not limited, as long as it can be replaced at any time during the use of the dissolving iron anode. In addition, the dissolving iron anode has a low specific surface area structure, and its specific surface area is less than 10.

[0025] In summary, the electroplating chromium-containing wastewater will obtain electrons in the cathode chamber and convert hexavalent chromium into trivalent chromium. In the anode chamber, the dissolving iron anode will lose electrons during dissolution to generate ferrous ions, and the hexavalent chromium will be reduced to trivalent chromium by the ferrous ions. Among them, the electrons lost during the generation of ferrous ions will be transferred to the cathode chamber through the conductive diaphragm and further promote the conversion of hexavalent chromium into trivalent chromium in the cathode chamber. That is, hexavalent chromium is treated in the cathode chamber and the anode chamber respectively, and the cathode chamber and the anode chamber promote the hexavalent chromium reduction process respectively by transferring electrons through the conductive diaphragm. Among them, the water inlet and the water outlet form a continuous flow channel. The water flow direction in this continuous flow channel is to pass through the cathode chamber and the anode chamber in sequence, and the overall flow direction of the electroplating chromium-containing wastewater will be perpendicular to the cathodes and anodes in the cathode chamber and the anode chamber, so as to ensure the maximum contact area between the electroplating chromium-containing wastewater and the cathodes and anodes.

[0026] In addition, the device is also equipped with an electrode spacing adjustment mechanism and a flow channel control system. The electrode spacing adjustment mechanism is used to adjust the spacing between any adjacent electrodes in the treatment unit, and the flow channel control system is used to control the wastewater flow rate in the continuous flow channel. Among them, the adjustable range of the electrode spacing is 5 to 50 cm, and the wastewater flow rate is controlled at 0.2 to 3 m per second.

[0027] In this embodiment, the conductive diaphragm is an asbestos diaphragm or a cation exchange membrane.

[0028] Among them, the specific thickness of the conductive diaphragm is 0.5 to 3 mm, the ion migration number is greater than or equal to 0.8, and the hexavalent chromium interception rate is greater than or equal to 0.95. In addition, the material used for the conductive diaphragm will separate the hexavalent chromium in the cathode chamber and the anode chamber. Since the electroplating chromium-containing wastewater passes through the cathode chamber and the anode chamber in sequence, a concentration gradient difference of hexavalent chromium will be generated between the cathode chamber and the anode chamber under the isolation of the conductive diaphragm, so as to achieve an effective effect when treating the electroplating chromium-containing wastewater through the treatment unit, that is, the hexavalent chromium concentration in the cathode chamber is higher than that in the anode chamber, and its high concentration will not affect the hexavalent chromium reduction reaction in the anode chamber.

[0029] In this embodiment, the surface catalytic material of the carbon-based cathode adopts a composite oxide for providing an active reaction site.

[0030] Among them, the composite oxide can specifically be a mixture of titanium dioxide and manganese dioxide, with a loading amount of 0.08 to 0.2, a specific surface area of greater than or equal to 500, and a porosity of 0.7 to 0.9.

[0031] In this embodiment, the dissolving iron anode is configured with a mechanical replacement mechanism, and the mechanical replacement mechanism is used to trigger automatic replacement when the anode consumption reaches a preset value.

[0032] Among them, the dissolving iron anode is made of cast iron with an iron content of greater than or equal to 0.98, and the surface roughness Ra = 5 to 20.

[0033] In this embodiment, the flow channel control system includes a baffle plate group and a flow guiding grid, so that the wastewater forms a turbulent flow in the cathode chamber and a laminar flow in the anode chamber.

[0034] Among them, the Reynolds number Re of the turbulent flow is greater than or equal to 4000, and the Reynolds number Re of the laminar flow is greater than or equal to 2000.

[0035] In this embodiment, the device further includes a concentration gradient monitoring module, and the concentration gradient monitoring module is used to detect the concentration difference of hexavalent chromium between the cathode chamber and the anode chamber in real time, and feedback adjustment information to the electrode spacing adjustment mechanism and the flow channel control system to adaptively adjust the electrode spacing and flow rate.

[0036] Among them, the highest standard for the concentration difference between the cathode chamber and the anode chamber isolated by the conductive diaphragm is 200 milligrams per liter.

[0037] In summary, the electroplating chromium-containing wastewater treatment device provided in this embodiment can realize the reduction treatment of hexavalent chromium-containing wastewater without an external power supply and other chemicals. Its core framework is as follows: 1. A reaction treatment unit is provided with a conductive diaphragm in the middle, dividing the treatment unit into a cathode chamber and an anode chamber; 2. The cathode uses a carbon substrate coated with a high specific surface area catalytic material, and the substrate is selected from carbon felt, granular activated carbon, porous graphite or other non-dissolving materials; 3. The anode uses a dissolving iron material with a low specific surface area and needs to be replaced according to usage requirements; 4. The diaphragm is selected from conductive membrane materials such as asbestos diaphragm or available cation exchange membranes, which are used to isolate hexavalent chromium ions, form a concentration gradient and ensure conductivity; 5. The water inlet device is designed to make the wastewater pass through the cathode first and then through the anode, and at the same time adjust the electrode spacing according to actual needs; 6. During the operation of the device, a stable concentration gradient is formed by controlling the removal rates of the cathode chamber and the anode chamber (specifically controlling the reaction conditions); 7. Reaction chamber flow channel design, by reasonably arranging electrodes, controlling the wastewater to flow through the reaction device at a certain flow rate in sequence.

[0038] Based on the above problems, the embodiments of the present application provide an electroplating chromium-containing wastewater treatment device and an electroplating chromium-containing wastewater treatment method. Referring to Figure 2 , Figure 2 is a schematic flow chart of an embodiment of the electroplating chromium-containing wastewater treatment device and the electroplating chromium-containing wastewater treatment method of the present application.

[0039] In this embodiment, the electroplating chromium-containing wastewater treatment method is applied to an electroplating chromium-containing wastewater treatment device. The device includes a reaction treatment unit, a conductive diaphragm, a carbon-based cathode, a leaching-type iron anode, a water inlet and a water outlet. The method includes the following steps: S10, flowing the electroplating chromium-containing wastewater to be treated from the water inlet into the cathode chamber in the reaction treatment unit. Near the carbon-based cathode, hexavalent chromium in the electroplating chromium-containing wastewater obtains electrons and is converted into trivalent chromium, and then flows into the anode chamber in the reaction treatment unit; S20, generating ferrous ions by the leaching-type iron anode losing electrons, and reducing the remaining hexavalent chromium in the electroplating chromium-containing wastewater into trivalent chromium by the ferrous ions, and making the wastewater flowing through the cathode chamber and the anode chamber in sequence flow out from the water outlet; wherein, electron movement is generated between the cathode chamber and the anode chamber through the conductive diaphragm; S30, performing acid-base adjustment and flocculation on the outflowing wastewater, and performing mud-water separation and concentration after acid-base adjustment and flocculation.

[0040] In this embodiment, it further includes subjecting the separated sludge to microwave pyrolysis treatment to generate iron-chromium composite oxide for the regeneration of the catalytic material of the carbon-based cathode.

[0041] The electroplating chromium-containing wastewater treatment device provided in this embodiment can realize the reduction treatment of hexavalent chromium-containing wastewater without adding external power and other chemicals, and in the whole device, hexavalent chromium can be reduced to trivalent chromium in both the cathode chamber and the anode chamber, ensuring the treatment efficiency. The specific application process of this device is as follows: First, the electroplating chromium-containing wastewater flows into the cathode chamber. The cathode chamber is arranged with a carbon-based material coated with a high specific surface area catalytic material on the surface according to conditions. Near the cathode, hexavalent chromium in the water obtains electrons and is converted into trivalent chromium, the concentration of hexavalent chromium decreases, and the toxicity decreases; then it flows into the anode chamber. The anode chamber is arranged with a leaching-type iron material according to conditions. Ferrous ions are generated by the anode losing electrons, and the remaining hexavalent chromium in the water is reduced to trivalent chromium.

[0042] Among them, in this device, by reasonably arranging the cathode and anode materials and controlling the flow rate of the wastewater, the purpose of removing hexavalent chromium is achieved. The whole process does not require additional acid supplementation, external power supply, or other soluble reducing agents. At the same time, hydrogen ions are consumed during the reaction, reducing the amount of alkali used, minimizing the conductivity of the water, greatly benefiting the subsequent deep treatment of the wastewater, and slowing down the scaling phenomenon of the structure. Finally, after the wastewater flows out of the device, it is adjusted for acid-base and flocculated, and then subjected to mud-water separation and concentration. The overall process can be referred to Figure 3 。

[0043] Among them, the concentration of hexavalent chromium in the influent is controlled to 100 to 800 mg / L, and the initial pH value is 2.0 to 4.0.

[0044] Among them, the wastewater flows through the cathode chamber and the anode chamber in sequence at a linear flow rate of 0.2 to 3 m / s. The reduction rate of hexavalent chromium in the cathode chamber is controlled to 0.7 to 0.9, and the total reduction rate in the anode chamber is greater than or equal to 0.995.

[0045] Among them, a concentration gradient of hexavalent chromium between the cathode chamber and the anode chamber greater than or equal to 150 mg / L is maintained through a conductive diaphragm.

[0046] Among them, after the effluent is adjusted to a pH of 7.5 to 9.0, a flocculant is added for mud-water separation.

[0047] Among them, the operating conditions of the cathode chamber are: potential of 0.8 to 1.2 V, and temperature of 30 to 50 °C.

[0048] Among them, the potential in the anode chamber naturally rises to 0.3 to 0.2 V, and the iron dissolution rate is 0.1 to 0.5.

[0049] Among them, by adjusting the consumption rate of the dissolving iron anode to match the catalytic activity of the carbon-based cathode, the self-driven current is stabilized at 1 to 10.

[0050] Based on the above, the specific advantages of the electroplating chromium-containing wastewater treatment device and the electroplating chromium-containing wastewater treatment method used in this embodiment are as follows: 1. The cathode with a surface-coated high specific surface area catalytic material provides more active reaction sites and improves the reduction efficiency of hexavalent chromium.

[0051] 2. The special diaphragm system can not only ensure electron conduction but also isolate hexavalent chromium ions, forming an effective concentration gradient.

[0052] 3. It has a wide applicable pH range, does not require additional acid supplementation, has stable treatment effects, consumes hydrogen ions during the reaction, and reduces the subsequent alkali dosage.

[0053] 4. Under the condition of no external power supply, chromium-containing wastewater with a certain concentration can be treated. Under the condition of an external power supply, the treatment efficiency is improved and the treatment concentration can be increased.

[0054] 5. The reaction device does not require additional dosing, and the operating cost is low.

[0055] 6. By reasonably controlling the removal efficiency of the cathode chamber and the anode chamber, an optimal concentration gradient is formed to improve the overall treatment efficiency.

[0056] 7. The segmented removal strategy reduces the load of a single reaction chamber and improves the system stability.

[0057] In this embodiment, it is applied to an electroplating chromium-containing wastewater treatment device. The device includes a reaction treatment unit, a conductive diaphragm, a carbon-based cathode, a dissolution-type iron anode, a water inlet and a water outlet. The electroplating chromium-containing wastewater to be treated flows into the cathode chamber in the reaction treatment unit from the water inlet. Near the carbon-based cathode, hexavalent chromium in the electroplating chromium-containing wastewater gains electrons and is converted into trivalent chromium, and then flows into the anode chamber in the reaction treatment unit; ferrous ions are generated by the dissolution-type iron anode losing electrons, and the remaining hexavalent chromium in the electroplating chromium-containing wastewater is reduced to trivalent chromium by the ferrous ions, and the wastewater that sequentially passes through the cathode chamber and the anode chamber flows out from the water outlet; wherein, electron movement is generated between the cathode chamber and the anode chamber through the conductive diaphragm; the outflowing wastewater is subjected to acid-base adjustment and flocculation, and after acid-base adjustment and flocculation, it is subjected to mud-water separation and concentration. Thus, under the treatment effect of the carbon-based anode, conductive diaphragm, and dissolution-type iron anode of the electroplating chromium-containing wastewater treatment device on electroplating chromium-containing wastewater, without additional chemical agents or continuous power supply, only relying on the spontaneous electron movement between the cathode, anode, and conductive diaphragm, the effects of obtaining electrons by hexavalent chromium and converting it into trivalent chromium in the cathode chamber and reducing hexavalent chromium to trivalent chromium using ferrous ions can be achieved respectively, and in the dual treatment scheme, the content of hexavalent chromium in the electroplating chromium-containing wastewater is effectively reduced, thereby achieving the effect of treating electroplating chromium-containing wastewater at low cost.

[0058] It should be noted that the above examples are only for understanding the present application and do not constitute a limitation on the electroplating chromium-containing wastewater treatment device and the electroplating chromium-containing wastewater treatment method of the present application. Based on this technical concept, more forms of simple transformations are within the protection scope of the present application.

[0059] As described above, the above are only the specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present application, and all should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

[0060] The above are only some embodiments of the present application, and thus do not limit the patent scope of the present application. Any equivalent structural transformation made under the technical concept of the present application by using the content of the specification and drawings of the present application, or any direct / indirect application in other related technical fields, is included in the patent protection scope of the present application.

[0061] It should be noted that in this text, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or system. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or system including the element.

[0062] The serial numbers of the embodiments of the present application above are only for description and do not represent the superiority or inferiority of the embodiments.

[0063] The above are only the preferred embodiments of the present application, and thus do not limit the patent scope of the present application. Any equivalent structural or equivalent process transformation made by using the content of the specification and drawings of the present application, or any direct or indirect application in other related technical fields, is similarly included in the patent protection scope of the present application.

Claims

1. An electroplating chromium-containing wastewater treatment device, characterized in that, The device includes a reaction processing unit, a conductive diaphragm, a carbon-based cathode, a dissolving iron anode, an inlet and an outlet; the reaction processing unit is separated into a cathode chamber and an anode chamber by the conductive diaphragm, and an ion conduction and a concentration gradient system for hexavalent chromium isolation are formed based on the cathode chamber and the anode chamber; the carbon-based cathode is arranged in the cathode chamber and is distributed in several parallel layers in the cathode chamber, and a high specific surface area catalytic material is coated on the surface of each layer of the carbon-based cathode. Among them, the carbon-based cathode is selected from non-dissolving materials such as carbon felt, granular activated carbon or porous graphite; the dissolving iron anode is arranged in the anode chamber and is distributed in several parallel layers in the anode chamber, and each layer of the dissolving iron anode is a low specific surface area replaceable structure; the inlet and the outlet form a continuous flow channel, and the water flow direction in the continuous flow channel is to pass through the cathode chamber and the anode chamber in sequence; the device is also equipped with an electrode spacing adjustment mechanism and a flow channel control system. The electrode spacing adjustment mechanism is used to adjust the spacing between any adjacent electrodes in the processing unit, and the flow channel control system is used to control the waste water flow rate in the continuous flow channel.

2. The device according to claim 1, characterized in that, The conductive diaphragm is an asbestos diaphragm or a cation exchange membrane.

3. The device according to claim 1, characterized in that, The surface catalytic material of the carbon-based cathode uses a composite oxide for providing an active reaction site.

4. The device according to claim 1, characterized in that, The dissolving iron anode is configured with a mechanical replacement mechanism, and the mechanical replacement mechanism is used to trigger automatic replacement when the anode consumption reaches a preset value.

5. The device according to claim 1, characterized in that The flow channel control system includes a baffle plate group and a flow guide grid, so that the waste water forms a turbulent flow in the cathode chamber and a laminar flow in the anode chamber.

6. The device according to claim 1, wherein The device also includes a concentration gradient monitoring module, which is used to detect the hexavalent chromium concentration difference between the cathode chamber and the anode chamber in real time, and feedback adjustment information to the electrode spacing adjustment mechanism and the flow channel control system to adaptively adjust the electrode spacing and the flow rate.

7. A method for treating electroplating chromium-containing wastewater, characterized in that, Applied to an electroplating chromium-containing wastewater treatment device, the device includes a reaction processing unit, a conductive diaphragm, a carbon-based cathode, a dissolving iron anode, an inlet and an outlet. The method includes the following steps: flowing the electroplating chromium-containing wastewater to be treated into the cathode chamber in the reaction processing unit from the inlet, and near the carbon-based cathode, the hexavalent chromium in the electroplating chromium-containing wastewater obtains electrons and is converted into trivalent chromium, and then flows into the anode chamber in the reaction processing unit; the dissolving iron anode loses electrons to generate ferrous ions, and the remaining hexavalent chromium in the electroplating chromium-containing wastewater is reduced to trivalent chromium by the ferrous ions, and the wastewater passing through the cathode chamber and the anode chamber in sequence flows out from the outlet; among them, electron movement is generated between the cathode chamber and the anode chamber through the conductive diaphragm; the outflowing wastewater is subjected to acid-base adjustment and flocculation, and after acid-base adjustment and flocculation, it is subjected to mud-water separation and concentration.

8. The method according to claim 7, wherein It also includes subjecting the separated sludge to microwave pyrolysis treatment to generate iron-chromium composite oxide for the regeneration of the catalytic material of the carbon-based cathode.

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