Waste lithium battery slurry production wastewater recycling device

Abstract

The utility model discloses a waste lithium battery slurry production wastewater recycling device which comprises a pretreatment device, a biochemical concentration device, an MBR (Membrane Biological Reactor) filter assembly, an NF (Non-filtration) membrane filter assembly, a dechlorination resin tank and an evaporator, and the pretreatment device comprises a coagulative precipitation tank and a filter press which are sequentially communicated along the wastewater conveying direction; the biochemical concentration device is communicated with the water outlet end of the filter press and is used for carrying out nitrogen and phosphorus removal treatment and COD (Chemical Oxygen Demand) reduction treatment on the wastewater; the MBR filter assembly comprises an MBR membrane tank, and the MBR membrane tank is communicated with the water outlet end of the biochemical concentration device; the NF membrane filtration assembly is provided with a water inlet, a water outlet and a concentrated water outlet, and the water inlet is communicated with the water outlet end of the MBR membrane tank; the dechlorination resin tank is communicated with the water outlet; the evaporator is communicated with the concentrated water outlet; according to the utility model, the wastewater is treated by the pretreatment device, the biochemical concentration device, the MBR membrane pool, the NF membrane filtration assembly and the dechlorination resin tank in sequence, so that the wastewater can be discharged or recycled.

Description

Technical Field

[0001] The utility model relates to the field of lithium battery recycling, in particular to a device for recycling the production wastewater of waste lithium battery slurry. Background Technique

[0002] In the process of recycling battery slurry, the common processes are crushing, pulping, pressure filtration and distillation purification. During the recycling process, electrolyte (NMP) wastewater will be generated. If the waste slurry is directly discharged, it will not only cause waste of resources, but also cause great pollution to the environment and pose huge potential safety hazards. Content of the Utility Model

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. For this purpose, the utility model provides a device for recycling the production wastewater of waste lithium battery slurry.

[0004] The technical solution of the utility model is as follows, including a pretreatment device, a biochemical concentration device, an MBR filtration component, an NF membrane filtration component, a dechlorination resin tank and an evaporator. The pretreatment device includes a coagulation sedimentation tank and a filter press. The water outlet end of the coagulation sedimentation tank is communicated with the water inlet end of the filter press. A stirring device is installed in the coagulation sedimentation tank, and the stirring device is used to stir the wastewater and calcium hydroxide solution in the coagulation sedimentation tank; a biochemical concentration device, which is communicated with the water outlet end of the filter press, and the biochemical concentration device is used to perform denitrification and phosphorus removal treatment on the wastewater and reduce the COD; the MBR filtration component includes an MBR membrane tank, and the MBR membrane tank is communicated with the water outlet end of the biochemical concentration device; the NF membrane filtration component has a water inlet, a water outlet and a concentrated water outlet, and the water inlet is communicated with the water outlet end of the MBR membrane tank; the dechlorination resin tank is communicated with the water outlet; the evaporator is communicated with the concentrated water outlet.

[0005] Further, the biochemical concentration device includes an anoxic adsorption tank, an anaerobic fermentation tank, an anoxic tank and an aerobic tank. The anoxic adsorption tank, the anaerobic fermentation tank, the anoxic tank and the aerobic tank are sequentially communicated along the wastewater conveying direction. The anoxic adsorption tank is communicated with the water outlet end of the filter press, and the water outlet end of the aerobic tank is communicated with the water inlet end of the MBR membrane tank.

[0006] Further, the bottom of the anoxic adsorption tank is communicated with the bottom of the anaerobic fermentation tank. There is a first overflow device for liquid to pass through between the top of the anaerobic fermentation tank and the top of the anoxic tank. There is a second overflow device for liquid to pass through between the top of the anoxic tank and the top of the aerobic tank. There is a third overflow device for liquid to pass through between the top of the aerobic tank and the top of the MBR membrane tank.

[0007] Further, it further includes a return water pipe, a first pump, and a second pump. One end of the return water pipe is communicated with the anoxic adsorption tank through a first communication pipe, and the return water pipe is communicated with the anoxic tank through a second communication pipe. Valves are arranged on both the first communication pipe and the second communication pipe. The other end of the return water pipe is connected with a first water outlet pipe and a second water outlet pipe. The first water outlet pipe is inserted into the MBR membrane tank and is provided with the first pump, and the second water outlet pipe is inserted into the aerobic tank and is provided with the second pump. The connection point between the second communication pipe and the return water pipe is located between the connection point between the second water outlet pipe and the return water pipe and the connection point between the first communication pipe and the return water pipe.

[0008] Further, it further includes an MBR cleaning water tank, a third water outlet pipe, and a third pump. An MBR membrane module is arranged in the MBR membrane tank. The MBR cleaning water tank is connected with the MBR membrane module through the third water outlet pipe, and a third pump is arranged on the third water outlet pipe.

[0009] Further, the MBR filtration assembly further includes an MBR water outlet tank, which is connected between the water outlet end of the MBR membrane tank and the water inlet. The wastewater in the MBR membrane tank enters the NF membrane filtration assembly through the MBR water outlet tank.

[0010] Further, it further includes a security filter, an NF cleaning water tank, and an NF water inlet tank. The water inlet end of the NF water inlet tank is communicated with the MBR membrane tank, the water outlet end of the NF water inlet tank is communicated with the security filter through a fourth water outlet pipe, the water outlet end of the security filter is communicated with the NF membrane filtration assembly, a fourth pump is arranged on the fourth water outlet pipe, and the NF cleaning water tank is communicated with the fourth water outlet pipe.

[0011] Further, it further includes a concentrated water tank. The concentrated water outlet is communicated with the water inlet end of the concentrated water tank, and the water outlet end of the concentrated water tank is communicated with the evaporator through a fifth water outlet pipe. A fifth pump is arranged on the fifth water outlet pipe.

[0012] Further, the condensate outlet of the evaporator is communicated with the water inlet end of the dechlorination resin tank, and the regeneration waste liquid generated by the dechlorination resin tank enters the evaporator through a third communication pipe.

[0013] Further, it further includes an NF water outlet tank and a resin water outlet tank. The NF water outlet tank is connected between the water outlet and the water inlet end of the dechlorination resin tank, and the resin water outlet tank is communicated with the water outlet end of the dechlorination resin tank.

[0014] The waste lithium battery slurry production wastewater recycling device according to the present utility model has at least the following technical effects: the pretreatment device can remove most of the heavy metals, suspended solids and part of phosphates in the wastewater; the biochemical concentration device can perform denitrification and phosphorus removal treatment on the wastewater and reduce the COD; the MBR membrane tank can improve the water quality of the effluent; the NF membrane filtration module can remove most of the sulfate radicals in the water; the evaporator can concentrate and crystallize the concentrated water discharged from the NF membrane filtration module; the dechlorination resin tank can further treat the water filtered by the NF membrane filtration module to remove the residual chloride ions in the water, so that the wastewater meets the discharge or recycling standard.

[0015] Additional aspects and advantages of the present utility model will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Additional aspects and advantages of the present utility model will become apparent and be readily understood from the description of the technical solutions in conjunction with the following drawings, wherein:

[0017] Figure 1 is a schematic structural diagram of the waste lithium battery slurry production wastewater recycling device of the technical solution of the present utility model;

[0018] Figure 2 is a schematic structural diagram of the connection between the biochemical concentration device and the MBR membrane tank;

[0019] Figure 3 is a schematic structural diagram of the connection between the MBR cleaning water tank and the MBR effluent tank and the MBR membrane tank;

[0020] Figure 4 is a schematic structural diagram of the connection between the NF inlet tank, the NF cleaning water tank and the security filter and the NF membrane filtration module;

[0021] Figure 5 is a schematic structural diagram of the connection between the NF membrane filtration module, the concentrated water tank, the evaporator, the NF effluent tank and the dechlorination resin tank.

[0022] Reference numerals: pretreatment device 100, coagulation sedimentation tank 110, filter press 120, regulating tank 130, coagulation effluent tank 140, biochemical concentration device 200, anoxic adsorption tank 210, anaerobic fermentation tank 220, anoxic tank 230, aerobic tank 240, MBR membrane tank 300, MBR membrane module 310, NF membrane filtration module 400, NF effluent tank 401, water inlet 410, water outlet 420, concentrated water outlet 430, security filter 440, NF cleaning water tank 450, NF inlet tank 460, high-pressure pump 461, fourth water outlet pipe 470, fourth pump 480, concentrated water tank 490, fifth water outlet pipe 491, fifth pump 492, dechlorination resin tank 500, air vent 501, pickling water inlet 502, sampling port 503, resin effluent tank 510, third connecting pipe 520, evaporator 600, condensate outlet 610, return pipe 700, first connecting pipe 710, second connecting pipe 720, valve 730, first water outlet pipe 740, second water outlet pipe 750, first pump 760, second pump 770, MBR cleaning water tank 800, third water outlet pipe 810, third pump 820, MBR effluent tank 900. Detailed implementation manners

[0023] The technical solutions of the present utility model will be described in detail below. Examples of the technical solutions are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The technical solutions described below with reference to the drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation to the present utility model.

[0024] In the description of the present utility model, if the first and the second are described, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence of the indicated technical features.

[0025] In the description of the present utility model, unless otherwise clearly defined, words such as "set", "installed", and "connected" should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meanings of the above words in the present utility model in combination with the specific content of the technical solutions.

[0026] The main characteristics of the battery paste recycling wastewater are high COD (10000 - 15000 mg / L), heavy metals (Ni, Co, Mn, Cu, Zn) ≤ 50 mg / L, chloride ions ≤ 300 mg / L, sulfate radicals ≤ 2000 mg / L, ammonia nitrogen ≤ 240 mg / L, TP (total phosphorus) ≤ 50 mg / L, F (fluoride) ≤ 10 mg / L, pH (acidity and alkalinity of the wastewater) = 6 - 9, SS (suspended solids) = 200 - 400 mg / L.

[0027] Chemical Oxygen Demand (COD) is the amount of reducible substances in a water sample that need to be oxidized, measured by chemical methods.

[0028] MBR (Membrane Bioreactor) is a new type of water treatment technology that combines a membrane separation unit with a biological treatment unit. It replaces the secondary sedimentation tank with a membrane module to maintain a high activated sludge concentration in the bioreactor, reducing the land area occupied by sewage treatment facilities, and reducing the amount of sludge by maintaining a low sludge load.

[0029] NF (Nanofiltration) is used to separate substances with relatively small molecular weights, such as inorganic salts or small molecule organic compounds like glucose and sucrose, from the solvent. Nanofiltration is also known as low-pressure reverse osmosis and is an emerging field of membrane separation technology. Its separation performance is between reverse osmosis and ultrafiltration, allowing some inorganic salts and certain solvents to pass through the membrane, thus achieving the separation effect.

[0030] The following further elaborates on the embodiments of the present utility model in conjunction with the accompanying drawings.

[0031] Refer to Figure 1 As shown, the waste lithium battery slurry production wastewater reuse device provided in the embodiments of the present utility model includes a pretreatment device 100, a biochemical concentration device 200, an MBR filtration component, an NF membrane filtration component 400, a dechlorination resin tank 500, and an evaporator 600. The pretreatment device 100 includes a coagulation sedimentation tank 110 and a filter press 120. The water outlet end of the coagulation sedimentation tank 110 is communicated with the water inlet end of the filter press 120. A stirring device is installed in the coagulation sedimentation tank 110, and the stirring device is used to stir the wastewater and calcium hydroxide solution in the coagulation sedimentation tank 110; the biochemical concentration device 200 is communicated with the water outlet end of the filter press 120, and the biochemical concentration device 200 is used for denitrification and phosphorus removal treatment of the wastewater and for reducing COD; the MBR filtration component includes an MBR membrane tank 300, and the MBR membrane tank 300 is communicated with the water outlet end of the biochemical concentration device 200; the NF membrane filtration component 400 has a water inlet 410, a water outlet 420, and a concentrated water outlet 430, and the water inlet 410 is communicated with the water outlet end of the MBR membrane tank 300; the dechlorination resin tank 500 is communicated with the water outlet 420; the evaporator 600 is communicated with the concentrated water outlet 430.

[0032] The pretreatment device 100 can remove most of the heavy metals, suspended solids, and part of the phosphate in the wastewater; the biochemical concentration device 200 can perform denitrification and phosphorus removal treatment on the wastewater and reduce COD; the MBR membrane tank 300 can improve the water quality of the effluent; the NF membrane filtration component 400 can remove most of the sulfate radicals in the water; the evaporator 600 can concentrate and crystallize the concentrated water discharged from the NF membrane filtration component 400; the dechlorination resin tank 500 can further treat the water filtered by the NF membrane filtration component 400 to remove the residual chloride ions in the water, making the wastewater meet the discharge or recycling standard.

[0033] As Figure 1 shown, during operation:

[0034] 1. Wastewater is transported into the coagulation sedimentation tank 110, and calcium hydroxide solution is added to the coagulation sedimentation tank 110 with a dosage of 300 ppm. The pH of the wastewater is adjusted to between 8 and 9.5. The solution and wastewater inside the coagulation sedimentation tank 110 can be stirred by a stirring device, and the reaction time is 15 - 30 min;

[0035] 2. The coagulation sedimentation tank 110 transports the wastewater onto the filter press 120. The filter press 120 presses the wastewater with a pressure of 0.6 Mpa. The filter cake after pressing is transported outside the filter press 120, and the water after pressing is transported onto the biochemical concentration device 200. The effluent indexes of the water after pressing are heavy metals ≤ 0.5 mg / L, SS ≤ 50 mg / L, TP ≤ 30 mg / L, F ≤ 5 mg / L, and sulfate radical ≤ 1500 mg / L;

[0036] 3. The biochemical concentration device 200 conducts biochemical reaction treatment on the wastewater to denitrify and dephosphorize the wastewater, and simultaneously reduce the COD. The treated wastewater is transported onto the MBR membrane tank 300;

[0037] 4. The MBR membrane tank 300 conducts solid-liquid separation on the wastewater, enhances the aerobic biochemical treatment effect, and improves the effluent quality. The treated wastewater is transported to the NF membrane filtration module 400;

[0038] 5. The NF membrane filtration module 400 filters the wastewater, controls the water production recovery rate at 80%, the inlet pressure of the NF membrane filtration module 400 is 1 MPa, and the inter-stage pressure difference ≤ 0.2 MPa, which can remove most of the sulfate radicals in the water; the concentrated water generated during filtration is transported to the evaporator 600 through the concentrated water outlet 430, and the evaporator 600 concentrates and crystallizes the concentrated water; the filtered water is transported to the dechlorination resin tank 500 through the water outlet 420. The dechlorination resin is amine type with an ion exchange capacity of 1.45 mmol / ml. The operation is in the up-in and down-out mode, the operation pH is 6 - 7, and the flow rate is 4 BV / h, which can remove the residual chloride ions in the water. The water treated by the chlorine resin tank can be discharged or reused.

[0039] Furthermore, as Figure 1 shown, the pretreatment device 100 further includes an adjustment tank 130. The inlet end of the adjustment tank 130 is connected to the external raw water end, and the outlet end of the adjustment tank 130 is connected to the inlet end of the coagulation sedimentation tank 110 through a pipeline. A pump is arranged on the pipeline. By setting the adjustment tank 130, the wastewater can be temporarily stored and the wastewater can be homogenized and adjusted to ensure the stability of the wastewater quality.

[0040] Furthermore, as Figure 1As shown, a pump is installed in the pipeline between the coagulation sedimentation tank 110 and the filter press 120, facilitating the conveyance of wastewater to the filter press 120.

[0041] Furthermore, as Figure 1 shown, the filter press 120 is a plate and frame filter press. By using the plate and frame filter press to perform solid-liquid separation on the wastewater, it can ensure the removal of most of the SS, heavy metals, and part of the phosphate in the wastewater; the inlet end of the pipeline between the coagulation sedimentation tank 110 and the filter press 120 is located at the bottom of the coagulation sedimentation tank 110 to ensure the normal filtration of the filter press 120.

[0042] Furthermore, as Figure 1 shown, a coagulated effluent tank 140 is provided between the filter press 120 and the biochemical concentration device 200. The coagulated effluent tank 140 is used to receive the wastewater after solid-liquid separation by the filter press 120; specifically, the wastewater in the coagulated effluent tank 140 can enter the biochemical concentration device 200 by means of overflow.

[0043] Furthermore, the evaporator 600 is a double-effect evaporator to ensure the effect of liquid concentration and crystallization.

[0044] Furthermore, as Figure 2 shown, the biochemical concentration device 200 includes an anoxic adsorption tank 210, an anaerobic fermentation tank 220, an anoxic tank 230, and an aerobic tank 240 that are connected in sequence along the wastewater conveyance direction. The anoxic adsorption tank 210 is connected to the outlet end of the filter press 120, and the outlet end of the aerobic tank 240 is connected to the MBR membrane tank 300. By providing the anoxic adsorption tank 210, the anaerobic fermentation tank 220, the anoxic tank 230, and the aerobic tank 240, it is ensured that the biochemical concentration device 200 can perform denitrification and phosphorus removal treatment on the wastewater and reduce the COD treatment;

[0045] Furthermore, as Figure 2 shown, the bottom of the anoxic adsorption tank 210 is connected to the bottom of the anaerobic fermentation tank 220. There is a first overflow device (not shown in the figure) for liquid passage between the top of the anaerobic fermentation tank 220 and the top of the anoxic tank 230. There is a second overflow device (not shown in the figure) for liquid passage between the top of the anoxic tank 230 and the top of the aerobic tank 240. There is a third overflow device (not shown in the figure) for liquid passage between the top of the aerobic tank 240 and the top of the MBR membrane tank 300, so that no pipelines need to be provided between each tank, making the device structure simple. Specifically, the first overflow device, the second overflow device, and the third overflow device are overflow holes.

[0046] As Figure 2 shown, during operation:

[0047] 1. Wastewater enters the anoxic adsorption tank 210. Under the action of the combined packing in the anoxic adsorption tank 210, sludge adheres to the wall, and the dissolved oxygen is controlled within 0.5 mg / L. A certain amount of decoupler is added to the tank, and the dosage is 50 ppm. The conversion efficiency of ADP / ATP is inhibited by the decoupler, so that organic matter is converted into internal carbon source for storage to avoid carbon source competition.

[0048] 2. The bottom of the anoxic adsorption tank 210 is connected to the bottom of the anaerobic fermentation tank 220. Wastewater enters the anaerobic fermentation tank 220 from the bottom. Submersible agitators can be installed in the anoxic adsorption tank 210 and the anaerobic fermentation tank 220 to prevent a large amount of granular sludge from being produced due to sludge accumulation. The pH in the anaerobic fermentation tank 220 can be controlled between 7.5 and 8, the water temperature is 35°C - 40°C, the influent load is controlled at 20 kgCOD / (m3·d), and the retention time HRT = 10 - 15 h.

[0049] 3. When the COD of the water in the anaerobic fermentation tank 220 ≤ 8000 mg / L, the anaerobic fermentation tank 220 can enter the anoxic tank 230 by overflow. The dissolved oxygen in the anoxic tank 230 is controlled within 0.2 mg / L. In the anoxic tank 230, heterotrophic bacteria hydrolyze suspended pollutants and soluble organic matter such as starch, fiber, and carbohydrates in the sewage into organic acids, decompose macromolecular organic matter into small-molecular organic matter, and convert insoluble organic matter into soluble organic matter.

[0050] 4. The anoxic tank 230 can enter the aerobic tank 240 by overflow. The dissolved oxygen in the aerobic tank 240 is controlled at 2 - 4 mg / L. In the aerobic tank 240, activated sludge performs aerobic respiration to further decompose organic matter into inorganic matter.

[0051] Specifically, the bottom of the aerobic tank 240 can adopt microporous aeration discs, and the microporous aeration discs provide oxygen for microorganisms.

[0052] Furthermore, as Figure 2As shown in the figure, it further includes a return water pipe 700, a first pump 760 and a second pump 770. One end of the return water pipe 700 is connected to the anoxic adsorption tank 210 through a first connecting pipe 710, and the return water pipe 700 is connected to the anoxic tank 230 through a second connecting pipe 720. Valves 730 are provided on both the first connecting pipe 710 and the second connecting pipe 720. The other end of the return water pipe 700 is connected with a first water outlet pipe 740 communicating with the MBR membrane tank 300 and a second water outlet pipe 750 communicating with the aerobic tank 240. A first pump 760 is provided on the first water outlet pipe 740, and a second pump 770 is provided on the second water outlet pipe 750. The connection point between the second connecting pipe 720 and the return water pipe 700 is located between the connection point between the second water outlet pipe 750 and the return water pipe 700 and the connection point between the first connecting pipe 710 and the return water pipe 700. By opening and closing the first pump 760 and the valve 730, the sludge concentration is controlled to ensure that the sludge concentration in the MBR membrane tank 300 is in the range of 8000 - 10000 mg / L, and by opening and closing the second pump 770 and the valve 730, ammonia nitrogen is removed through denitrification. Moreover, by providing the return water pipe 700, the wastewater in the MBR membrane tank 300 and the aerobic tank 240 can flow back to the anoxic tank 230 or the anoxic adsorption tank 210, thereby controlling the sludge concentration at the front end of the biochemical concentration device 200.

[0053] Further, as Figure 3 shown in the figure, it further includes an MBR cleaning water tank 800, a third water outlet pipe 810 and a third pump 820. An MBR membrane module 310 is provided in the MBR membrane tank 300. The MBR cleaning water tank 800 is connected to the MBR membrane module 310 through the third water outlet pipe 810. A third pump 820 is provided on the third water outlet pipe 810. By providing the MBR cleaning water tank 800 and the third water outlet pipe 810, the MBR membrane module 310 can be cleaned through the MBR cleaning water tank 800 to ensure the normal operation of the MBR membrane module 310.

[0054] Further, as Figure 3 shown in the figure, the MBR filtration component further includes an MBR water outlet tank 900. The MBR water outlet tank 900 is connected between the water outlet end of the MBR membrane tank 300 and the water inlet 410. The wastewater in the MBR membrane tank 300 enters the NF membrane filtration component 400 through the MBR water outlet tank 900 to temporarily store the wastewater treated by the MBR membrane tank 300 through the MBR water outlet tank 900.

[0055] Further, as Figure 1 、 4 shown in the figure, a security filter 440 is connected between the MBR membrane tank 300 and the NF membrane filtration component 400 to remove the suspended solids remaining in the wastewater through the security filter 440.

[0056] Further, as Figure 4As shown, a high-pressure pump 461 is provided in the pipeline between the security filter 440 and the NF membrane filtration module 400, and wastewater is conveyed to the NF membrane filtration module 400 through the high-pressure pump 461.

[0057] Further, as Figure 1 , 4 shown, an NF cleaning water tank 450 is connected between the MBR membrane tank 300 and the security filter 440. The NF membrane filtration module 400 can be cleaned through the NF cleaning water tank 450 to ensure the normal operation of the NF membrane filtration module 400.

[0058] Further, as Figure 1 , 4 shown, an NF water inlet tank 460 is further included. The water inlet end of the MBR membrane tank 300 is communicated with the water inlet end of the NF water inlet tank 460, and the water outlet end of the NF water inlet tank 460 is communicated with the security filter 440 through a fourth water outlet pipe 470. A fourth pump 480 is provided on the fourth water outlet pipe 470. By providing the NF water inlet tank 460, wastewater can be temporarily stored, enabling the fourth pump 480 to convey the wastewater to the NF membrane filtration module 400 in a high-pressure manner.

[0059] Further, as Figure 5 shown, a concentrated water tank 490 is further included. The concentrated water outlet 430 of the NF membrane filtration module 400 is communicated with the water inlet end of the concentrated water tank 490, and the water outlet end of the concentrated water tank 490 is communicated with the evaporator 600 through a fifth water outlet pipe 491. A fifth pump 492 is provided on the fifth water outlet pipe 491. By providing the concentrated water tank 490, concentrated water can be temporarily stored.

[0060] Further, as Figure 5 shown, the condensate water outlet 610 of the evaporator 600 is communicated with the water inlet end of the dechlorination resin tank 500, so that the dechlorination resin tank 500 can treat the condensate water discharged from the evaporator 600 to fully treat the wastewater; the regeneration waste liquid generated by the dechlorination resin tank 500 enters the evaporator 600 through a third communication pipe 520 to fully recover the wastewater.

[0061] Further, as Figure 5 shown, an NF water outlet tank 401 is connected between the NF membrane filtration module 400 and the dechlorination resin tank 500. The NF water outlet tank 401 is used to temporarily store the water filtered by the NF membrane filtration module 400, facilitating the conveyance of the filtered water to the dechlorination resin tank 500 for treatment.

[0062] Further, as Figure 1 shown, the water outlet end of the dechlorination resin tank 500 is connected with a resin water outlet tank 510. The resin water outlet tank 510 is used to temporarily store the water stored in the dechlorination resin tank 500, facilitating the reuse or external discharge of the treated water.

[0063] Further, as Figure 1 shown, the top of the dechlorination resin tank 500 is provided with a vent port 501, which is convenient for discharging the gas inside the dechlorination resin tank 500.

[0064] Further, as Figure 1 shown, the side wall of the dechlorination resin tank 500 is provided with a pickling water inlet 502, which is convenient for introducing pickling water into the dechlorination resin tank 500.

[0065] Further, as Figure 1 shown, a sampling port 503 is provided in the pipeline between the dechlorination resin tank 500 and the resin effluent tank 510, which is convenient for sampling the water treated by the dechlorination resin tank 500.

[0066] As Figure 1 、 2 、3, 4, and 5 shown, when the utility model works:

[0067] 1. The wastewater first enters the regulation tank 130 for homogeneous mixing, and then enters the coagulation sedimentation tank 110 through a lift pump. A calcium hydroxide solution is added in the coagulation sedimentation tank 110, and the dosage is 300 ppm. The pH of the wastewater is adjusted to between 8 and 9.5. The coagulation sedimentation tank 110 is equipped with stirring, and the reaction time is 15 - 30 min;

[0068] 2. The wastewater enters the plate and frame filter press (filter press 120) through a lift pump to achieve full filtration. When the feed pressure of the plate and frame filter press reaches 0.6 Mpa, the filtration stops, and the filter cake is transported out; the water discharged from the plate and frame filter press goes to the coagulation effluent tank 140;

[0069] 3. The effluent indexes of the coagulation effluent tank 140 are: heavy metals ≤ 0.5 mg / L, SS ≤ 50 mg / L, TP ≤ 30 mg / L, F ≤ 5 mg / L, sulfate radical ≤ 1500 mg / L;

[0070] 4. The wastewater enters the anoxic adsorption tank 210 by overflow in the coagulation effluent tank 140. In the anoxic adsorption tank 210, sludge is attached to the wall by using a combined filler, and the dissolved oxygen is controlled within 0.5 mg / L; a certain amount of decoupling agent is added in the tank, and the dosage is 50 ppm. The conversion efficiency of ADP / ATP is inhibited by the decoupling agent, so that the organic matter is converted into internal carbon source for storage to avoid carbon source competition;

[0071] 5. The bottom of the anoxic adsorption tank 210 is connected to the anaerobic fermentation tank 220, and the wastewater enters the anaerobic fermentation tank 220 from the bottom. A submersible stirrer is installed in the tank to prevent a large amount of granular sludge from being accumulated due to sludge backlog. The pH in the anaerobic fermentation tank 220 is controlled between 7.5 and 8, and the water temperature is 35 - 40 °C; the influent load is controlled at 20 kgCOD / (m3·d), and the retention time HRT = 10 - 15 h;

[0072] 6. When the COD of the effluent from the anaerobic fermentation tank 220 is ≤ 8000 mg / L, it overflows to the anoxic tank 230. The anoxic tank 230 controls the dissolved oxygen within 0.2 mg / L. Heterotrophic bacteria in the anoxic tank 230 hydrolyze suspended pollutants and soluble organic matters such as starch, fiber, and carbohydrates in the sewage into organic acids, decompose macromolecular organic matters into small-molecular organic matters, and convert insoluble organic matters into soluble organic matters.

[0073] 7. The water in the anoxic tank 230 enters the aerobic tank 240. The aerobic tank 240 controls the dissolved oxygen at 2 - 4 mg / L. Micro-porous aeration discs are adopted at the bottom of the aerobic tank 240 to provide oxygen for microorganisms.

[0074] 8. The wastewater in the aerobic tank 240 overflows to the MBR membrane tank 300. The MBR membrane tank 300 adopts the activated sludge process and is internally equipped with plate-type MBR membrane modules 310. There is no biochemical effluent sedimentation tank, which enhances the aerobic biochemical treatment effect and improves the effluent quality. The biochemical concentration device 200 is provided with a return pipe 700, and it can be selectively returned to the anoxic tank 230 or the anoxic adsorption tank 210. By refluxing, the sludge concentration at the front end of the biochemical concentration device 200 can be controlled.

[0075] 9. The effluent from the MBR membrane tank 300 flows to the MBR effluent tank 800 for temporary storage. The wastewater overflows from the MBR effluent tank 800 to the NF influent tank 460, and then is transported to the security filter 440. The security filter 440 removes the residual SS in the wastewater.

[0076] 10. The NF influent tank 460 transports the wastewater to the NF membrane filtration module 400 through the fourth outlet pipe 470 and the fourth pump 480. The NF membrane filtration module 400 removes most of the sulfate radicals in the wastewater, controls the water production recovery rate at 80%, the inlet pressure of the NF membrane filtration module 400 is 1 MPa, and the inter-stage pressure difference is ≤ 0.2 MPa. Under the action of the pressure difference driving force, salts and small-molecular substances permeate through the nanofiltration membrane, and the membrane pore size is 10 -1 nm.

[0077] 11. The concentrated water generated by the NF membrane filtration module 400 enters the concentrated water tank 490. The concentrated water tank 490 transports the concentrated water to the evaporator 600 through the fifth outlet pipe 491 and the fifth pump 492. The water filtered by the NF membrane filtration module 400 enters the NF effluent tank 401. The condensed water generated by the evaporator 600 returns to the NF effluent tank 401.

[0078] 12. The wastewater in the NF effluent tank 401 is pumped by a pump to the dechlorination resin tank 500. The dechlorination resin is of amine type, with an ion exchange capacity of 1.45 mmol / ml. The operation mode is from top to bottom, the operation pH is 6 - 7, the flow rate is 4 BV / h, and the regeneration is carried out with a 5% sodium hydroxide solution; the regeneration waste liquid enters the evaporator 600, and the water treated by the dechlorination resin tank 500 enters the resin effluent tank 510;

[0079] 13. The effluent indexes of the resin effluent tank 510 are: heavy metals ≤ 0.5 mg / L, SS ≤ 20 mg / L, TP ≤ 2 mg / L, F ≤ 1 mg / L, sulfate radical ≤ 100 mg / L, COD ≤ 50 mg / L, ammonia nitrogen ≤ 20 mg / L, chloride ion ≤ 10 mg / L, and the effluent is recycled to the front - end production workshop.

[0080] The utility model is provided with a pretreatment device 100, a biochemical concentration device 200, an MBR membrane tank 300, an NF membrane filtration module 400, a dechlorination resin tank 500 and an evaporator 600, so that the wastewater is sequentially treated by the pretreatment device 100, the biochemical concentration device 200, the MBR membrane tank 300, the NF membrane filtration module 400 and the dechlorination resin tank 500, enabling the wastewater to be discharged or recycled.

[0081] Although the technical solutions of the utility model have been shown and described, those of ordinary skill in the art can understand that: without departing from the principles and purposes of the utility model, these technical solutions can be subject to various changes, modifications, substitutions and variations, and the scope of the utility model is defined by the claims and their equivalents.

Claims

1. A device for recycling wastewater from the production of waste lithium battery slurry, characterized in that, Comprising: A pretreatment device (100), including a coagulation sedimentation tank (110) and a filter press (120), the water outlet end of the coagulation sedimentation tank (110) is communicated with the water inlet end of the filter press (120), a stirring device is installed in the coagulation sedimentation tank (110), and the stirring device is used for stirring the wastewater and calcium hydroxide solution in the coagulation sedimentation tank (110); A biochemical concentration device (200), communicated with the water outlet end of the filter press (120), and the biochemical concentration device (200) is used for performing denitrification and phosphorus removal treatment on the wastewater and reducing the COD; An MBR filtration component, including an MBR membrane tank (300), and the MBR membrane tank (300) is communicated with the water outlet end of the biochemical concentration device (200); An NF membrane filtration component (400), having a water inlet (410), a water outlet (420) and a concentrated water outlet (430), and the water inlet (410) is communicated with the water outlet end of the MBR membrane tank (300); A dechlorination resin tank (500), communicated with the water outlet (420); An evaporator (600), communicated with the concentrated water outlet (430).

2. The waste lithium battery slurry production wastewater reuse device according to claim 1, wherein: The biochemical concentration device (200) includes an anoxic adsorption tank (210), an anaerobic fermentation tank (220), an anoxic tank (230) and an aerobic tank (240), the anoxic adsorption tank (210), the anaerobic fermentation tank (220), the anoxic tank (230) and the aerobic tank (240) are communicated in sequence along the wastewater conveying direction, the anoxic adsorption tank (210) is communicated with the water outlet end of the filter press (120), and the water outlet end of the aerobic tank (240) is communicated with the water inlet end of the MBR membrane tank (300).

3. The waste lithium battery slurry production wastewater reuse device according to claim 2, wherein: The bottom of the anoxic adsorption tank (210) is communicated with the bottom of the anaerobic fermentation tank (220), there is a first overflow device for liquid to pass through between the top of the anaerobic fermentation tank (220) and the top of the anoxic tank (230), there is a second overflow device for liquid to pass through between the top of the anoxic tank (230) and the top of the aerobic tank (240), and there is a third overflow device for liquid to pass through between the top of the aerobic tank (240) and the top of the MBR membrane tank (300).

4. The waste lithium battery slurry production wastewater reuse device according to claim 2, wherein: It further includes a return water pipe (700), a first pump (760) and a second pump (770). One end of the return water pipe (700) is communicated with the anoxic adsorption tank (210) through a first connecting pipe (710). The return water pipe (700) is communicated with the anoxic tank (230) through a second connecting pipe (720). Valves (730) are arranged on both the first connecting pipe (710) and the second connecting pipe (720). The other end of the return water pipe (700) is connected with a first water outlet pipe (740) and a second water outlet pipe (750). The first water outlet pipe (740) is inserted into the MBR membrane tank (300) and is provided with the first pump (760). The second water outlet pipe (750) is inserted into the aerobic tank (240) and is provided with the second pump (770). The connection point between the second connecting pipe (720) and the return water pipe (700) is located between the connection point between the second water outlet pipe (750) and the return water pipe (700) and the connection point between the first connecting pipe (710) and the return water pipe (700).

5. The waste lithium battery slurry production wastewater reuse device according to claim 1, characterized in that: It further includes an MBR cleaning water tank (800), a third water outlet pipe (810) and a third pump (820). An MBR membrane module (310) is arranged in the MBR membrane tank (300). The MBR cleaning water tank (800) is connected with the MBR membrane module (310) through the third water outlet pipe (810). A third pump (820) is arranged on the third water outlet pipe (810).

6. The waste lithium battery slurry production wastewater reuse device according to claim 1, characterized in that: The MBR filtration assembly further includes an MBR water outlet tank (900). The MBR water outlet tank (900) is connected between the water outlet end of the MBR membrane tank (300) and the water inlet (410). The wastewater in the MBR membrane tank (300) enters the NF membrane filtration assembly (400) through the MBR water outlet tank (900).

7. The waste lithium battery slurry production wastewater recycling device according to claim 1, wherein: It further includes a security filter (440), an NF cleaning water tank (450) and an NF water inlet tank (460). The water inlet end of the NF water inlet tank (460) is communicated with the MBR membrane tank (300). The water outlet end of the NF water inlet tank (460) is communicated with the security filter (440) through a fourth water outlet pipe (470). The water outlet end of the security filter (440) is communicated with the NF membrane filtration assembly (400). A fourth pump (480) is arranged on the fourth water outlet pipe (470). The NF cleaning water tank (450) is communicated with the fourth water outlet pipe (470).

8. The waste lithium battery slurry production wastewater reuse device according to claim 1, characterized in that: It further includes a concentrated water tank (490). The concentrated water outlet (430) is communicated with the water inlet end of the concentrated water tank (490). The water outlet end of the concentrated water tank (490) is communicated with the evaporator (600) through a fifth water outlet pipe (491). A fifth pump (492) is arranged on the fifth water outlet pipe (491).

9. The waste lithium battery slurry production wastewater reuse device according to claim 1, wherein: The condensate outlet (610) of the evaporator (600) is communicated with the water inlet end of the dechlorination resin tank (500), and the regeneration waste liquid generated by the dechlorination resin tank (500) enters the evaporator (600) through the third communication pipe (520).

10. The waste lithium battery slurry production wastewater recycling device according to claim 1, characterized in that: It further includes an NF effluent tank (401) and a resin effluent tank (510). The NF effluent tank (401) is connected between the water outlet (420) and the water inlet end of the dechlorination resin tank (500), and the resin effluent tank (510) is communicated with the water outlet end of the dechlorination resin tank (500).

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