Modular integrated electrolysis-electrocoagulation wastewater treatment system and process

Abstract

The present invention is used in the technical field of wastewater treatment. Disclosed is a modular integrated electrolysis-electrocoagulation wastewater treatment system. The wastewater treatment system comprises a C module, an A module, a B module, an S module, and an F module. In the modular integrated electrolysis-electrocoagulation wastewater treatment system, when treating different types of wastewater, a plurality of treatment modules are combined and installed in a specific sequence, and when conductive electrode plates are energized, pollutants in the water undergo redox reactions, so that the pollutants in the wastewater can react with different metal ions to form flocs, and the flocs precipitate out. For different types of wastewater, the same types of treatment modules are used but are installed in different sequences. Provided is a working mode in which the treatment sequence varies for different types of pollutants, so that some pollutants that are initially non-reactive with a specified module can react with the specified module after undergoing electrolysis or electrocoagulation reactions with other modules, thereby achieving a better treatment effect.

Description

A modular combined electrolysis and electrocoagulation wastewater treatment system and process

[0001] Cross-referencing

[0002] This application claims priority to Chinese application No. 202410903999.4, filed on July 8, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of wastewater treatment technology, specifically to a modular combined electrolysis and electrocoagulation wastewater treatment system and process. Background Technology

[0004] With industrial development, wastewater discharged during industrial production contains large amounts of organic matter, heavy metals, and other harmful substances. If discharged directly into the environment without treatment, it will inevitably have adverse effects on the surrounding environment and ecosystem. The construction and operation of industrial wastewater treatment plants can deeply treat industrial wastewater, removing harmful substances, sediments, and pigments, and enabling water reuse, ultimately reducing environmental pollution. The large amount of water used in industrial production has further exacerbated the scarcity of water resources. The construction and operation of industrial wastewater treatment plants can purify industrial wastewater and reuse recyclable water, reducing the pressure on industry's demand for freshwater resources such as tap water. The construction and operation of industrial wastewater treatment plants are beneficial to environmental protection and water conservation.

[0005] To control and reduce the harm of industrial wastewater discharge, many industrial enterprises adopt different treatment methods. The basic methods of industrial wastewater treatment mainly include physical treatment, chemical treatment, biological treatment, and integrated treatment. Physical treatment refers to the process of treating industrial wastewater using a series of physical methods, such as sand filtration, membrane filtration, and centrifugation. These methods directly act on particulate matter in the wastewater, or remove impurities through filtration and separation, obtaining relatively clean water. Chemical treatment refers to the method of treating industrial wastewater using various agents. This method can eliminate impurities and microorganisms through chemical reactions, improving wastewater quality. For example, oxidants are used to oxidize pollutants, and precipitants are used to precipitate heavy metal ions. Although chemical methods can quickly remove large amounts of pollutants, the cost of the agents is relatively high. The cost is relatively high, and the energy and water consumption is also relatively large, requiring careful selection. Biological treatment methods refer to the treatment of wastewater using biologically active substances. By contacting wastewater with microorganisms, the microorganisms can absorb and metabolize the organic matter in the water. This method can not only reduce costs but also achieve a certain degree of resource conservation. Therefore, biological treatment is becoming increasingly common. Integrated treatment refers to the treatment of industrial wastewater by combining physical, chemical, and biological methods. Integrated treatment methods can reduce reliance on a single method and improve wastewater treatment efficiency and quality. For example, biological treatment can be used first to degrade organic pollutants, and then oxidants can be used to degrade the remaining pollutants. There are many methods for industrial wastewater treatment. If only a single method is used, it is difficult to achieve good treatment results. However, using multiple treatment methods will make the treatment process too complex and place too high demands on the equipment.

[0006] Summary of the Invention

[0007] The purpose of this invention is to provide a modular combination of electrolysis and electrocoagulation wastewater treatment system and process to solve the problem of complex treatment processes mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a modular combined electrolysis and electrocoagulation wastewater treatment system, wherein the wastewater treatment system includes module C, module A, module B, module S and module F;

[0009] Module C: This is a box-shaped graphite electrolysis module with an internal conductive electrode plate made of high-density graphite.

[0010] Module A: This is a box-shaped aluminum electrocoagulation processing module, with an internal conductive electrode plate made of pure aluminum metal plate.

[0011] Module B: This is a box-shaped ferroelectric coagulation processing module, with an internal conductive electrode plate made of ferrometallic plates.

[0012] S module: Set as a solid-liquid separation module, including a slag scraping system and a conical bottom sedimentation structure;

[0013] Module F: This module is set as a membrane treatment module, containing an ultrafiltration membrane assembly and a diaphragm filter press assembly.

[0014] Preferably, the wastewater treatment system is composed of any two or more different modules, and the inlet and outlet ends of the different modules in the wastewater treatment system are connected in series through pipes, and the same modules in the wastewater treatment system are arranged in parallel.

[0015] Preferably, the number of conductive electrode plates in the C, A, and B module housings is between 50 and 150, and the area of ​​the conductive electrode plate is greater than 0.2 m², and the length of one side of the conductive electrode plate is greater than 0.5 m.

[0016] Preferably, the conductive electrode plates in the C, A, and B module housings are evenly distributed within the housing, and the distance between two adjacent conductive electrode plates in the housing is 4-9 mm, and the two adjacent conductive electrode plates are arranged in parallel.

[0017] Preferably, the conductive electrode plates located at both ends of the enclosure in modules C, A, and B are connected to the power supply. The number of conductive electrode plates at both ends of the enclosure in modules C, A, and B connected to the positive terminal of the power supply is greater than or equal to 1 and less than or equal to 2. The number of conductive electrode plates at both ends of the enclosure in modules C, A, and B connected to the negative terminal of the power supply is greater than or equal to 1 and less than or equal to 2. Furthermore, the conductive electrode plates connected to the positive and negative terminals of the power supply are located at different ends of the enclosure in modules C, A, and B, respectively.

[0018] Preferably, the voltage range of the power supply is 100-400V.

[0019] Preferably, the flow velocity of wastewater on the surface of the conductive electrode plate in the C, A, and B module housings is 30 L / m. 2 h-150L / m 2 Within the range of h, the sewage fills the boxes of modules C, A, and B from the lower end, and the upper end of the boxes of modules C, A, and B is provided with an overflow edge, and the number of overflow edges at the upper end of the boxes of modules C, A, and B is greater than or equal to 3.

[0020] Preferably, the S-module is a parallel box design, and the S-module box is provided with a slag scraping structure and a bottom sedimentation structure, and the bottom sedimentation structure in the S-module box is a cone design with the tip pointing downwards.

[0021] Preferably, the filtration accuracy of the F module is higher than 30 nm, and the water flow rate of the F module is greater than 200 L / m³ under 1 Pa pressure. 2 ˙h.

[0022] A modular combined electrolysis and electrocoagulation wastewater treatment process includes the following steps:

[0023] S1: Select the modules that make up the system according to the type of wastewater;

[0024] S2: Connect the inlet and outlet ends of different modules in series through pipes according to the type of wastewater:

[0025] S3: Based on the design flow rate of wastewater treatment, different types of modules are installed in parallel. The inlet and outlet of each parallel-installed module are connected to the main pipeline through branch pipelines and connected in series with the previous and next level modules.

[0026] Compared with the prior art, the beneficial effects of the present invention are: the modular combined electrolysis and electrocoagulation wastewater treatment system:

[0027] Multiple treatment modules are combined and installed in a certain order to treat different types of wastewater. The pollutants in the water undergo oxidation-reduction reactions when the conductive electrode plate is energized, so that the pollutants in the wastewater can react with different metal ions to form flocs and precipitate out.

[0028] Furthermore, by using the same type of modules for different types of wastewater but with different installation sequences, a working method is provided that treats different types of pollutants in different orders. This allows some pollutants that do not originally react with the designated modules to react with the designated modules after electrolysis or electrocoagulation with other modules, thereby achieving better treatment results.

[0029] Furthermore, by employing a lower spacing between the conductive electrode plates and a higher voltage between the cathode and anode, a working method for electrocatalyzing pollutants in wastewater is provided, thereby enhancing the wastewater treatment effect. Moreover, by connecting identical devices in parallel and connecting different devices in series, the treatment capacity per unit time of the wastewater treatment system is increased. Attached Figure Description

[0030] Figure 1 is a schematic diagram of the integrated wastewater and electrophoretic wastewater treatment process system of Embodiment 1 of the present invention;

[0031] Figure 2 is a schematic diagram of the aluminum oxidation wastewater treatment process system of Embodiment 1 of the present invention;

[0032] Figure 3 is a schematic diagram of the composition of the wastewater treatment process system containing gold, silver, copper and nickel in Embodiment 1 of the present invention;

[0033] Figure 4 is a schematic diagram of the wastewater treatment process system of Embodiment 2 of the present invention;

[0034] Figure 5 is a schematic diagram of the integrated wastewater treatment process system of Embodiment 3 of the present invention;

[0035] Figure 6 is a schematic diagram of the chemical nickel wastewater treatment process system of Embodiment 3 of the present invention;

[0036] Figure 7 is a schematic diagram of the integrated wastewater treatment process system of Embodiment 4 of the present invention;

[0037] Figure 8 is a schematic diagram of the composition of the chromium-containing wastewater treatment process system in Embodiment 4 of the present invention;

[0038] Figure 9 is a schematic diagram of the composition of the nickel-containing wastewater treatment process system in Embodiment 4 of the present invention;

[0039] Figure 10 is a bar chart showing the ammonia nitrogen removal rate of different modules in Embodiment 1 of the present invention.

[0040] Figure 11 is a bar chart of COD removal rates for different module sequences in Embodiment 1 of the present invention;

[0041] Figure 12 is a bar chart showing the removal rates of different modules in Embodiment 1 of the present invention.

[0042] Figure 13 is a bar chart showing the removal rates of different modules in different order in Embodiment 3 of the present invention. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Please refer to Figures 1-13. The present invention provides a technical solution: a modular combined electrolysis and electrocoagulation wastewater treatment system, the wastewater treatment system including module C, module A, module B, module S and module F;

[0045] Module C: This is a box-shaped graphite electrolysis module with an internal conductive electrode plate made of high-density graphite.

[0046] Module A: This is a box-shaped aluminum electrocoagulation processing module, with an internal conductive electrode plate made of pure aluminum metal plate.

[0047] Module B: This is a box-shaped ferroelectric coagulation processing module, with an internal conductive electrode plate made of ferrometallic plates.

[0048] S module: Set as a solid-liquid separation module, including a slag scraping system and a conical bottom sedimentation structure;

[0049] Module F: This module is set as a membrane treatment module, containing an ultrafiltration membrane assembly and a diaphragm filter press assembly.

[0050] The wastewater treatment system consists of any two or more different modules mentioned above, and the inlet and outlet ends of the different modules in the wastewater treatment system are connected in series through pipes, and the same modules in the wastewater treatment system are set in parallel.

[0051] The number of conductive electrode plates in the C, A, and B module enclosures is between 50 and 150, and the area of ​​the conductive electrode plate is greater than 0.2㎡, and the length of one side of the conductive electrode plate is greater than 0.5m.

[0052] In the C, A, and B module enclosures, the conductive electrode plates are evenly distributed within the enclosure, with a spacing of 4-9mm between any two adjacent conductive electrode plates, and the two adjacent conductive electrode plates are arranged in parallel.

[0053] In modules C, A, and B, the conductive electrode plates located at both ends of the enclosure are connected to the power supply. The number of conductive electrode plates at both ends of the enclosure connected to the positive terminal of the power supply in modules C, A, and B is greater than or equal to 1 and less than or equal to 2. The number of conductive electrode plates at both ends of the enclosure connected to the negative terminal of the power supply in modules C, A, and B is greater than or equal to 1 and less than or equal to 2. Furthermore, the conductive electrode plates connected to the positive and negative terminals of the power supply are located at different ends of the enclosure in modules C, A, and B, respectively.

[0054] The power supply voltage range is 100-400V.

[0055] The flow velocity of wastewater on the surface of the conductive electrode plate in the C, A, and B module tanks is 30 L / m. 2 h-150L / m 2 Within the range of h, sewage fills the boxes of modules C, A, and B from the bottom, and overflow edges are provided at the top of the boxes of modules C, A, and B, with the number of overflow edges at the top of the boxes of modules C, A, and B being greater than or equal to 3.

[0056] The S-module is a parallel box design, and the S-module box is equipped with a slag scraping structure and a bottom sedimentation structure. The bottom sedimentation structure in the S-module box has a cone design with the tip pointing downwards.

[0057] The F module has a filtration accuracy higher than 30nm, and its flow rate is greater than 200L / m³ at 1Pa pressure. 2 ˙h.

[0058] A modular combined electrolysis and electrocoagulation wastewater treatment process includes the following steps:

[0059] S1: Select the modules that make up the system according to the type of wastewater;

[0060] S2: Connect the inlet and outlet ends of different modules in series through pipes according to the type of wastewater:

[0061] S3: Based on the design flow rate of wastewater treatment, different types of modules are installed in parallel. The inlet and outlet of each parallel-installed module are connected to the main pipeline through branch pipelines and connected in series with the previous and next level modules.

[0062] Example 1:

[0063] Wastewater from electroplating plants includes general wastewater, electrophoretic wastewater, aluminum oxidation wastewater, and wastewater containing gold, silver, copper, and nickel.

[0064] Combined wastewater

[0065] The final process design uses the wastewater treatment system shown in Figure 1 to treat the combined wastewater. The main pollutants in the water are COD, ammonia nitrogen, zinc ions, iron ions, and a small amount of hexavalent chromium. The wastewater enters module B for iron electrode electrolysis, with 140-150 electrodes. The wastewater flow velocity at each electrode surface is 70-90 L / m²·h. After treatment, the effluent enters module S for solid-liquid separation. The clarified liquid after solid-liquid separation enters module A for aluminum electrode electrolysis, with 140-150 electrodes. The wastewater flow velocity at each electrode surface is 75-100 L / m²·h. The treated water then enters module S for solid-liquid separation. The clarified liquid after solid-liquid separation enters the ultrafiltration membrane component in module F for filtration, yielding treated water. The sludge from solid-liquid separation in module S enters the diaphragm filter press component in module F for filtration. The water after diaphragm filter press treatment enters the raw water tank. The wastewater is treated from a dark brown color to clear and transparent treated water. The wastewater treatment results are shown in the table below.

[0066] Experimental Results Table

[0067] As shown in the table, the treated water after being treated by the sewage treatment system meets the discharge standards.

[0068] In determining the final process flow through experiments, we found that not only do the operating parameters of each module affect the removal rate, but the sequential arrangement of electrodes of different materials before and after treatment plays a more crucial role. Under identical operating parameters for each module (voltage, current, water flow rate on the electrode surface, etc.), the order of the modules significantly impacts the pollutant removal rate. Comparing the efficiency of treating ammonia nitrogen and COD in integrated wastewater treatment alone, the removal rate differs by at least 10-20% depending on the order. This also confirms our inference about the effects of combining multiple modules in series: during electrolytic flocculation on electrodes of different materials, it's not simply a matter of metal ion flocculants generated at the anode and hydroxyl ions generated at the cathode forming complex flocculants that separate pollutants from the water. Pollutants in the water undergo different catalytic oxidation-reduction reactions on the electrode surfaces of different materials, causing some water-soluble pollutants to undergo new changes. Therefore, this is not simply a matter of different metal ion flocculation effects, but rather that these new changes allow them to be captured by different metal ion flocculation processes.

[0069] For example, the pollutants in the water can be flocculated by iron ions deposited by the iron electrode and aluminum ions deposited by the aluminum electrode. So, no matter how the order of electrocoagulation is reversed, the final removal rate should be exactly the same. However, the actual result is that the difference is 10-20%, as shown in Figures 10 and 11. This shows that some pollutants in the water cannot be flocculated by iron or aluminum ions in their original state, but after electrolysis on the iron electrode surface, they become a substance that can be flocculated by aluminum ions. Therefore, they can be captured and separated in the subsequent aluminum electrode electrolysis flocculation process. The final result is that the removal rate is 10-20% higher when the iron electrode electrolysis treatment in module B is followed by the aluminum electrode electrolysis treatment in module A than when the order is reversed.

[0070] Because wastewater contains complex components, including dozens or even hundreds of chemicals in different arrangements and concentrations, all embodiments utilize combinations of different processing modules. This allows different pollutants in the water to be transformed into a form that can be processed by subsequent modules through electrolysis in the preceding process modules. The optimal treatment process is designed by optimizing various variables, including different operating parameters. Sometimes the electrode materials of the preceding and subsequent processes are the same, and sometimes they are different.

[0071] Electrophoresis wastewater

[0072] The final process design uses the wastewater treatment system shown in Figure 1 to treat electrophoresis wastewater.

[0073] Experimental Results Table

[0074] As shown in the table above, the treated water from the wastewater treatment system meets the discharge standards.

[0075] Aluminum Oxidation Wastewater

[0076] The process design uses the wastewater treatment system shown in Figure 2 to treat aluminum oxidation wastewater;

[0077] Aluminum oxidation wastewater enters the first A module treatment unit. The treated water from the first A module then enters the S module for solid-liquid separation. The clarified liquid from this separation enters the second A module treatment unit. The treated water from the second A module then enters the S module for solid-liquid separation. The clarified liquid then enters the ultrafiltration membrane unit of the F module for filtration, yielding treated water. The sludge from the solid-liquid separation in the S module enters the diaphragm filter press unit of the F module for filtration. The water treated by the diaphragm filter press in the F module enters the raw water tank. The wastewater treatment results are shown in the table below:

[0078] Experimental Results Table

[0079] As shown in the table above, the treated water from the wastewater treatment system meets the discharge standards.

[0080] Wastewater containing gold, silver, copper and nickel

[0081] The process design uses the wastewater treatment system shown in Figure 3 to treat wastewater containing gold, silver, copper, and nickel.

[0082] The combined wastewater enters the treatment module B, and after treatment, it enters module S for solid-liquid separation. The clarified liquid after solid-liquid separation enters module C. Module C has 70-80 electrode plates, and the wastewater flows at a velocity of 45-60 L / m² on each electrode surface. 2 After treatment, the wastewater enters module S for solid-liquid separation. The clarified liquid from solid-liquid separation enters module A for further treatment. The treated water then enters module S for solid-liquid separation. The clarified liquid from solid-liquid separation enters module F for ultrafiltration membrane treatment to obtain treated water. The sludge from solid-liquid separation in module S enters module F for diaphragm filter press treatment. The water treated by diaphragm filter press in module F enters the raw water tank. The wastewater treatment results are shown in the table below:

[0083] Experimental Results Table

[0084] As shown in the table above, the treated water from the wastewater treatment system meets the discharge standards.

[0085] As shown in Figure 12, in the design and development of processes for treating wastewater containing gold, silver, copper, and nickel, it was found that the order of modules sometimes only affects the removal rate by about 1%, but has a significant impact on whether the final standard is met. For example, for nickel emissions requiring less than 0.5 mg / L, the removal rates of the two treatment processes, B → C → A and C → A → B, differ by only 0.7%, but the latter results in effluent exceeding the standard by almost three times. Furthermore, in multiple reproducibility experiments, the difference in removal rate remained essentially the same, indicating that nickel in a certain complexed state in the water is removed in the B → C → A module treatment sequence, but cannot be removed in the C → A → B module process.

[0086] Example 2:

[0087] Electroplating plant wastewater includes various types such as general wastewater, pretreatment wastewater, stripping wastewater, electroless nickel plating wastewater, and chromium-containing wastewater. All wastewater contains varying concentrations of substances such as chromium, nickel, copper, phosphorus, and ammonia nitrogen. The concentrations of these substances are shown in the table below.

[0088] The concentration units in the table above are all in mg / L.

[0089] The design process mixes all the water before it enters the system, and the treatment flow is shown in Figure 4.

[0090] Wastewater enters the first B module treatment component. The treated water from the first B module then enters the S module for solid-liquid separation. The clarified liquid from this solid-liquid separation enters the A module treatment component. The treated water then enters the S module for solid-liquid separation. The clarified liquid from this solid-liquid separation enters the second B module treatment component. The treated water from the second B module then enters the S module for solid-liquid separation. The clarified liquid from this solid-liquid separation enters the ultrafiltration membrane component of the F module for filtration, yielding treated water. The sludge from the solid-liquid separation in the S module enters the diaphragm filter press component of the F module for filtration. The water from the diaphragm filter press in the F module enters the raw water tank. The wastewater is treated from a dark brown color to clear and transparent treated water. The wastewater treatment results are shown in the table below.

[0091] Experimental Results Table

[0092] As shown in the table above, most of the effluent from the wastewater treatment system meets the discharge standards.

[0093] Example 3:

[0094] Wastewater from electroplating plants includes general wastewater and chemical nickel wastewater.

[0095] The process design uses the wastewater treatment system shown in Figure 5 to treat the combined wastewater.

[0096] The combined wastewater enters the C module treatment component. Module C has 70-80 plates, and the wastewater flows at a velocity of 30-45 L / m²·h on each plate surface. After treatment, it enters the S module for solid-liquid separation. The clarified liquid after solid-liquid separation enters the A module treatment component. The wastewater flows at a velocity of 90-120 L / m²·h on each plate surface in module A. The treated water then enters the S module for solid-liquid separation. The clarified liquid after solid-liquid separation enters the B module treatment component. The wastewater flows at a velocity of 75-105 L / m²·h on each plate surface in module B. After treatment, it enters the S module for solid-liquid separation. The clarified liquid after solid-liquid separation enters the ultrafiltration membrane component of module F for filtration, yielding treated water. The sludge from the solid-liquid separation in module S enters the diaphragm filter press component of module F for filtration. The water after diaphragm filter press treatment in module F enters the raw water tank. The wastewater treatment results are shown in the table below:

[0097] Experimental Results Table

[0098] As shown in the table above, the treated water from the wastewater treatment system meets the discharge standards.

[0099] The process design uses the wastewater treatment system shown in Figure 6 to treat electroless nickel wastewater:

[0100] The combined wastewater enters the C module treatment unit, and after treatment, it enters the S module for solid-liquid separation. The clarified liquid after solid-liquid separation enters the B module treatment unit. The treated water enters the S module for solid-liquid separation, and the clarified liquid after solid-liquid separation enters the A module treatment unit. After treatment, it enters the S module for solid-liquid separation, and the clarified liquid after solid-liquid separation enters the F module's ultrafiltration membrane unit for filtration to obtain treated water. The sludge from the solid-liquid separation in the S module enters the F module's diaphragm filter press unit for filtration. The water after diaphragm filter press treatment in the F module enters the raw water tank. The wastewater treatment results are shown in the table below:

[0101] Experimental Results Table

[0102] As shown in the table above, most of the effluent from the wastewater treatment system meets the discharge standards.

[0103] As shown in Figure 13, significant differences in the order of module treatment can also be observed in the design and development of processes for treating nickel ore by electrolytic nickel. For example, for nickel concentrations requiring a discharge level of less than 0.5 mg / L, the removal rates of the C → A → B module process and the A → B → C module process differ by more than 5%, with the latter producing effluent that exceeds the standard by almost six times. In multiple reproducibility experiments, a consistently consistent difference in removal rates indicates that nickel in a complexed state is removed in the C → A → B module treatment sequence, but cannot be removed in the A → B → C module process.

[0104] Example 4:

[0105] Electroplating plant wastewater includes general wastewater, chromium-containing wastewater, and nickel-containing wastewater. General wastewater contains pollutants such as chromium, nickel, and cyanide, while chromium-containing wastewater contains hexavalent chromium, trivalent chromium, and nickel.

[0106] The process design uses the wastewater treatment system shown in Figure 7 to treat the combined wastewater;

[0107] The combined wastewater enters the A module treatment unit, and after treatment, it enters the S module for solid-liquid separation. The clarified liquid after solid-liquid separation enters the B module treatment unit. The treated water enters the S module for solid-liquid separation, and the clarified liquid after solid-liquid separation enters the ultrafiltration membrane unit of the F module for filtration to obtain treated water. The sludge from the solid-liquid separation in the S module enters the diaphragm filter press unit of the F module for filtration. The water after diaphragm filter press treatment in the F module enters the raw water tank. The wastewater treatment results are shown in the table below:

[0108] Experimental Results Table

[0109] As shown in the table above, the treated water from the wastewater treatment system meets the discharge standards.

[0110] The process design uses the wastewater treatment system shown in Figure 8 to treat chromium-containing wastewater:

[0111] Chromium-containing wastewater enters the first B module treatment component. The treated water from the first A module then enters the S module for solid-liquid separation. The clarified liquid from this separation enters the second A module treatment component. The treated water from the second B module then enters the S module for solid-liquid separation. The clarified liquid then enters the ultrafiltration membrane component of the F module for filtration, yielding treated water. The sludge from the solid-liquid separation in the S module enters the diaphragm filter press component of the F module for filtration. The water from the diaphragm filter press in the F module then enters the raw water tank. The wastewater treatment results are shown in the table below:

[0112] Experimental Results Table

[0113] As shown in the table above, the treated water from the wastewater treatment system meets the discharge standards.

[0114] The process design uses the wastewater treatment system shown in Figure 9 to treat nickel-containing wastewater:

[0115] Nickel-containing wastewater enters the B module treatment unit, and after treatment, it enters the S module for solid-liquid separation. The COD of the clarified liquid after solid-liquid separation decreases from over 12,000 to around 3,000. The clarified liquid after solid-liquid separation in the S module enters the C module treatment unit, and after treatment, it enters the S module for solid-liquid separation. The clarified liquid after solid-liquid separation enters the ultrafiltration membrane unit in the F module for filtration to obtain treated water. The sludge from solid-liquid separation in the S module enters the diaphragm filter press unit in the F module for treatment. The water after diaphragm filter press treatment in the F module enters the raw water tank. The wastewater treatment results are shown in the table below.

[0116] Experimental Results Table

[0117] As shown in the table above, the treated water from the wastewater treatment system meets the discharge standards.

[0118] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A modular combined electrolysis and electrocoagulation wastewater treatment system, characterized in that: The wastewater treatment system includes modules C, A, B, S, and F. Module C: This is a box-shaped graphite electrolysis module with an internal conductive electrode plate made of high-density graphite. Module A: This is a box-shaped aluminum electrocoagulation module with an internal conductive electrode plate made of pure aluminum metal. Module B: This is a box-shaped ferroelectric coagulation processing module, with an internal conductive electrode plate made of ferrometallic plates. S module: Set as a solid-liquid separation module, including a slag scraping system and a conical bottom sedimentation structure; Module F: This module is configured as a membrane treatment module, containing an ultrafiltration membrane assembly and a diaphragm filter press assembly.

2. The modular combined electrolysis and electrocoagulation wastewater treatment system according to claim 1, characterized in that: The wastewater treatment system is composed of any two or more different modules, and the inlet and outlet ends of the different modules in the wastewater treatment system are connected in series through pipes, and the same modules in the wastewater treatment system are set in parallel.

3. The modular combined electrolysis and electrocoagulation wastewater treatment system according to claim 1, characterized in that: The number of conductive electrode plates in the C, A, and B module housings is between 50 and 150, and the area of ​​the conductive electrode plate is greater than 0.2㎡, and the length of one side of the conductive electrode plate is greater than 0.5m.

4. The modular combined electrolysis and electrocoagulation wastewater treatment system according to claim 1, characterized in that: The conductive electrode plates in the C, A, and B module housings are evenly distributed within the housing, with a spacing of 4-9 mm between two adjacent conductive electrode plates, and the two adjacent conductive electrode plates are arranged in parallel.

5. The modular combined electrolysis and electrocoagulation wastewater treatment system according to claim 1, characterized in that: The conductive electrode plates located at both ends of the enclosure in modules C, A, and B are connected to the power supply. The number of conductive electrode plates at both ends of the enclosure in modules C, A, and B connected to the positive terminal of the power supply is greater than or equal to 1 and less than or equal to 2. The number of conductive electrode plates at both ends of the enclosure in modules C, A, and B connected to the negative terminal of the power supply is greater than or equal to 1 and less than or equal to 2. Furthermore, the conductive electrode plates connected to the positive and negative terminals of the power supply are located at different ends of the enclosure in modules C, A, and B, respectively.

6. The modular combined electrolysis and electrocoagulation wastewater treatment system according to claim 5, characterized in that: The voltage range of the power supply is 100-400V.

7. The modular combined electrolysis and electrocoagulation wastewater treatment system according to claim 1, characterized in that: The flow velocity of wastewater on the surface of the conductive electrode plate in the C, A, and B module housings is 30 L / m. 2 h-150L / m 2 Within the range of h, the sewage fills the boxes of modules C, A, and B from the lower end, and the upper end of the boxes of modules C, A, and B is provided with an overflow edge, and the number of overflow edges at the upper end of the boxes of modules C, A, and B is greater than or equal to 3.

8. A modular combined electrolysis and electrocoagulation wastewater treatment system according to claim 7, characterized in that: The S-module is a parallel box design, and the S-module box is equipped with a slag scraping structure and a bottom sedimentation structure. The bottom sedimentation structure in the S-module box is a cone-shaped design with the tip pointing downwards.

9. A modular combined electrolysis and electrocoagulation wastewater treatment system according to claim 1, characterized in that: The filtration accuracy of module F is higher than 30nm, and the water flow rate of module F is greater than 200L / m³ under 1Pa pressure. 2 ˙h.

10. A modular combined electrolysis and electrocoagulation wastewater treatment process, characterized in that: Includes the following steps: S1: Select the modules that make up the system according to the type of wastewater; S2: Connect the inlet and outlet ends of different modules in series through pipes according to the type of wastewater: S3: Based on the design flow rate of wastewater treatment, different types of modules are installed in parallel. The inlet and outlet of each parallel-installed module are connected to the main pipeline through branch pipelines and connected in series with the previous and next level modules.

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