Pesticide wastewater partitioned anaerobic membrane bioreactor treatment device

Abstract

The invention discloses a pesticide wastewater partitioned anaerobic membrane bioreactor treatment device, and relates to the technical field of pesticide wastewater treatment and recovery. Comprising a water inlet system for diluting and storing high-toxicity pesticide wastewater; iron-attached biochar is added into the partitioned UASB reactor, and a water inlet of the partitioned UASB reactor is communicated with a water outlet of the water inlet system; online monitoring equipment is arranged outside the external membrane tank, and a water inlet of the external membrane tank is communicated with a water outlet of the partitioned UASB reactor; the water outlet tank is connected with a membrane backwashing device, and biogas generated in the reaction process is collected by a gas collecting bag; the water inlet of the water outlet tank is communicated with the water outlet of the external membrane tank. The device can stably run for a long time, degradation of high-organic-load and high-toxicity pesticide sewage is realized, the energy recovery potential is improved, and membrane pollution is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of pesticide wastewater treatment and recovery, and in particular to a pesticide wastewater partitioned anaerobic membrane bioreactor treatment device. Background Art

[0002] Pesticides are important substances in agricultural production. They can be used to prevent, treat and control crop pests, weeds and diseases and improve the quality of agricultural products. China is one of the world's largest pesticide producers. According to data, the national output of chemical pesticide technical materials in 2023 will be 2.6711 million tons, with an output value of more than 100 billion yuan. With the increase in the use of pesticides, the safety of pesticides has attracted more and more attention. The water quality of pesticide wastewater is very complex. Taking organic sulfur pesticide wastewater as an example, its COD value is as high as 10000-20000 mg / L process wastewater, ammonia nitrogen is as high as 10000-30000 mg / L process wastewater, cyanide is 100-1000 mg / L, and it also contains high concentrations of technical active ingredients, total manganese, total zinc, ethylene thiourea, solvents, AOX, pyridine, aniline, nitrobenzene and other major new pollutants, which are extremely difficult to treat. Long-term exposure to these toxic and harmful substances in pesticide production wastewater has a strong inhibitory effect on the microbial enzyme activity of anaerobic bacteria, nitrifying bacteria and denitrifying bacteria, and has a toxic effect on the microbial system. Therefore, finding a process technology with low investment, low operating costs, and the ability to ensure that the effluent quality of pesticide wastewater meets the discharge standards for a long time is a hot topic for domestic and foreign water treatment experts, a focus of corporate attention, and a difficulty that needs to be solved urgently.

[0003] For example, a Chinese patent with publication number CN117797534A discloses a pesticide wastewater treatment device, which can effectively clean impurities and ensure the stability of the equipment, but it has a complex structure, high cost, high energy consumption, and difficult maintenance. In practical applications, it may be limited by poor adaptability and compliance with environmental regulations. A Chinese patent with publication number CN117800536A describes a process for treating triazotin pesticide wastewater, which includes multiple treatment units such as a comprehensive regulating tank, an iron-carbon tower, a Fenton tower, etc. Although this process shows good results in reducing the content of pollutants such as COD, ammonia nitrogen, total nitrogen, and total tin, it uses a variety of chemical agents such as sulfuric acid solution, hydrogen peroxide solution, sodium hydroxide solution, and coagulants, which may lead to an increase in treatment costs and secondary pollution. In addition, the multi-stage treatment process means that more monitoring and maintenance work is required, and problems in any link may lead to a decrease in the efficiency of the entire treatment process.

[0004] The pesticide wastewater treatment process has a large amount of chemical agents added, high pretreatment costs and sludge treatment costs, and high energy consumption. The cost of treating a ton of water can reach 10-78 yuan / m 3Water is the key factor that limits its engineering application. How to reduce the energy consumption of pesticide wastewater treatment, improve the energy recovery / consumption ratio, turn pesticide wastewater plants into energy plants, and sell surplus carbon quotas in the carbon trading market in order to bring huge economic benefits to enterprises is also a hot topic of current research. The use of anaerobic microorganisms to degrade organic matter in sewage reduces the demand for external energy, achieves low-energy operation, and reduces sludge production. The anaerobic membrane bioreactor (AnMBR) is an efficient treatment technology that combines anaerobic technology with membrane separation. It has good operational stability and is suitable for occasions with high requirements for wastewater treatment, ensuring long-term and stable wastewater treatment effects. It provides many advantages over traditional anaerobic processes, such as longer SRT, shorter HRT, less sludge generation, better effluent quality and rapid start-up of biological processes, with satisfactory COD removal and biogas production. The Chinese patent with publication number CN221460074U describes a composite AnMBR device for treating sewage; it can efficiently remove organic matter, nitrogen, phosphorus and other pollutants in sewage, achieve high effluent water quality standards, and meet strict environmental protection requirements. The Chinese patent with publication number CN117701365A discloses an external anaerobic membrane bioreactor for treating high-lipid food waste. It adopts a new technology combining anaerobic biological treatment with membrane separation, realizes the effective separation of SRT and HRT, improves the methane yield, maintains the protein, polysaccharide and COD removal rates above 95%, and the lipid degradation rate above 70%, realizing the stable operation of the system and efficient energy recovery of high-lipid food waste. Although the above patents have achieved good results in the treatment of various wastewaters, they have not been effectively applied to pesticide wastewater. Summary of the invention

[0005] The purpose of the present invention is to provide a zoned anaerobic membrane bioreactor treatment device for pesticide wastewater, which can operate stably for a long time, achieve the degradation of high organic load and high toxicity pesticide wastewater, improve energy recovery potential and reduce membrane pollution.

[0006] To achieve the above-mentioned purpose, the technical solution of the present application is: a partitioned anaerobic membrane bioreactor treatment device for pesticide wastewater, comprising:

[0007] Water inlet system, used to dilute and store highly toxic pesticide wastewater;

[0008] A partitioned UASB reactor is internally doped with iron-attached biochar, and the water inlet of the partitioned UASB reactor is connected to the water outlet of the water inlet system;

[0009] An external membrane pool is equipped with online monitoring equipment. The water inlet of the external membrane pool is connected to the water outlet of the partitioned UASB reactor.

[0010] The water outlet pool is connected with a membrane backwashing device; the water inlet of the water outlet pool is connected with the water outlet of the external membrane pool.

[0011] In one embodiment, the water inlet system comprises:

[0012] A buffer tank is used to eliminate the gas contained in the influent water; the buffer tank is provided with a water level sensor, which is connected to an automatic open-loop control system, which dilutes the influent water with tap water and causes a step change in the influent concentration;

[0013] A tap water storage tank is connected to the buffer tank via a flow meter and a first pneumatic valve, wherein the flow meter and the first pneumatic valve are also connected to an automatic open-loop control system;

[0014] A pesticide wastewater raw water storage tank is connected to the buffer tank via a second pneumatic valve, and the second pneumatic valve is also connected to an automatic open-loop control system;

[0015] The water inlet pool has a built-in agitator and a pH probe, and a water level sensor is arranged on the pool wall; the water inlet pool is connected to the buffer tank through a third pneumatic valve, and the pH probe, the water level sensor and the third pneumatic valve are also connected to an automatic open-loop control system.

[0016] In one embodiment, a heat exchanger is provided between the water inlet system and the zoned UASB reactor for adjusting the temperature of the water inlet, and the heat exchanger is connected to the heating rod;

[0017] Before the inlet water is heated, it is lifted to the heat exchanger by the first peristaltic pump. After the inlet water is heated, it is lifted to the water inlet of the partitioned UASB reactor by the second peristaltic pump, and the water temperature is monitored online by a temperature sensor.

[0018] In one embodiment, the zoned UASB reactor comprises:

[0019] Three digestion chambers are arranged side by side, each of which is provided with a corresponding first air chamber, a second air chamber, and a third air chamber, each of which is connected to a closed pipeline to prevent gas leakage; overflow ports are arranged on both sides of each air chamber, and the overflow ports are connected to the slag removal pipeline;

[0020] The water inlet structure has a first water inlet, a second water inlet, and a third water inlet, the system being a gravity flow distribution system, wherein a central water inlet well or water inlet channel overflows into a water inlet tank and is connected to the corresponding digestion chamber top water inlet through a pipe;

[0021] A first water inlet valve, arranged before the second water inlet;

[0022] A second water inlet valve is arranged before the third water inlet;

[0023] A water outlet is provided at the top of the reactor side wall, and a scum trap is provided on the water outlet and the gas-liquid interface surface;

[0024] A sampling system, comprising a first sampling port, a second sampling port, and a third sampling port arranged in sequence from bottom to top, a fourth sampling port is arranged on the opposite side of the third sampling port, a fifth sampling port is arranged on the opposite side of the second sampling port, and a sixth sampling port is arranged on the opposite side of the first sampling port, and the fourth sampling port, the fifth sampling port, and the sixth sampling port are arranged in sequence from top to bottom;

[0025] The first mud discharge port and the second mud discharge port are arranged at the lower part of the side wall of the reactor and are connected with the mud discharge pipeline, and a mud discharge pump is arranged on the mud discharge pipeline.

[0026] In one embodiment, a three-phase separator is provided on the top of each digestion chamber. The upper portion of the three-phase separator has a gas collecting hood, and the lower portion has a gas guide plate, and the guide plate is a gradually expanding opening structure.

[0027] In one embodiment, the discarded traditional Chinese medicine residue is converted into iron-attached biochar, and the concentration of the iron-attached biochar in the zoned UASB reactor is 5-10 g / L.

[0028] In one of the embodiments, a mixing pump is provided at the lower part of the external membrane tank, and part of the treated water is discharged through a membrane pressure gauge and a water outlet pump, and the membrane pressure gauge monitors the change of the trans-membrane pressure difference in real time; another part of the treated water flows into the partitioned UASB reactor through a reflux pump to mix with the sludge to ensure the sludge concentration in the reactor.

[0029] In one embodiment, the online monitoring equipment includes a TOC analyzer, a titration sensor, a UV spectrometer and a FT-IR spectrometer, which are used to online measure indicators in the effluent of the external membrane pool, including: soluble chemical oxygen demand COD, total organic carbon TOC, total volatile fatty acids VFA, acetate Ac, dissolved CO2, bicarbonate concentration, and total alkalinity and partial alkalinity.

[0030] In one of the embodiments, the biogas generated by the partitioned UASB reactor is discharged from the first air chamber, the second air chamber, and the third air chamber at the top through a closed pipeline. A wet gas flow meter is provided on the closed pipeline to measure the volume of the biogas and a gas sensor is used to measure the composition of the biogas. The discharged biogas passes through a condensate overflow device to keep the liquid level and pressure in the device constant, and is collected in a gas collecting bag.

[0031] In one embodiment, the membrane backwashing device adopts a combination of in-situ cleaning CIP and offline cleaning COP;

[0032] The CIP is performed using multiple cycles of backwashing and soaking, each cycle including 1-3 minutes of backwashing and 8-12 minutes of soaking, using NaOCl and NaOH as cleaning agents; followed by 25-35 minutes of pure permeate backwashing to remove cleaning agent residues in pipes and filters; followed by multiple cycles of backwashing and soaking, using citric acid and HCl, and performing CIP every 10-20 days;

[0033] Before offline cleaning of the COP, the membrane is removed from the external membrane tank, sprayed with water to rinse off the attached biomass, and then inserted into the COP tank and soaked with acidic cleaning solution or alkaline cleaning solution; the used acidic cleaning solution and alkaline cleaning solution are stored in the acid storage tank and the alkali storage tank respectively; the solids and debris are precipitated at the bottom of the tank and then taken out and processed separately; the COP is cleaned offline every 1.5-2.5 months.

[0034] The present invention adopts the above technical solution, and can achieve the following technical effects:

[0035] 1In the partitioned UASB reactor, the use of three independent digestion chambers can significantly improve the stability of the system. By optimizing the upward flow velocity and reducing the dead zone, the contact efficiency between the substrate and the biomass is significantly enhanced, thereby comprehensively improving the overall performance of the system. In addition, the small fluctuation characteristics of the upward flow velocity in each digestion chamber effectively limit the flushing of solids into the settling chamber.

[0036] 2 By converting discarded Chinese medicine residues into iron-attached biochar, not only can the resource utilization of waste be realized and the cost of raw materials for wastewater treatment be reduced, but also a new environmentally friendly and cost-effective material for wastewater treatment is provided. Iron-attached biochar has excellent adsorption capacity and porous structure, can effectively adsorb pollutants in water, and provide an ideal environment for the growth of microorganisms and the formation of biofilms, effectively promoting the chemical redox reaction of organic pollutants, while enhancing the metal removal efficiency.

[0037] 3 The buffer tank in the inlet water system is equipped with an automatic open-loop control system to dilute the inlet water with tap water and produce a step-change dilution factor (between 1 and 4) in the inlet water concentration.

[0038] 4 Since the guide plate has a gradually expanding opening structure, the formation of slag can be reduced; in addition, the design of the slag removal pipeline and slag interceptor can avoid blockage to a large extent.

[0039] 5. The in-situ cleaning strategy and the offline cleaning strategy of the membrane complement each other, greatly reducing the degree of membrane pollution, extending the service life of the membrane components, and ensuring the continuity and efficiency of the wastewater treatment process.

[0040] 6 To prevent gas leakage during anaerobic digestion, a closed pipeline is set on the top of the partitioned UASB reactor; the condensate overflow device can effectively deal with the accumulation of condensate caused by biogas cooling to keep the liquid level and pressure in the gas box constant. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0042] Figure 1 This is an overall schematic diagram of a zoned anaerobic membrane bioreactor treatment device for pesticide wastewater;

[0043] Figure 2 This is a schematic diagram of the water inlet system principle;

[0044] Figure 3 This is a schematic diagram of the water inlet of the partitioned UASB reactor;

[0045] Figure 4 It is a schematic diagram of a three-phase separator of a partitioned UASB reactor;

[0046] Figure 5 It is a schematic diagram of the guide plate of the partitioned UASB reactor;

[0047] Figure 6 This is a schematic diagram of the sludge collection in the partitioned UASB reactor;

[0048] Figure 7 This is a schematic diagram of the effluent from the partitioned UASB reactor;

[0049] Figure 8 This is a schematic diagram of sludge discharge in a partitioned UASB reactor;

[0050] Fig. 9 A simplified schematic diagram of an in-situ cleaning device for a membrane;

[0051] Fig.10 Simplified schematic diagram of the offline membrane cleaning equipment.

[0052] Explanation of the serial numbers in the figure: 1. water inlet tank; 2. partitioned UASB reactor; 3. external membrane tank; 4. water outlet tank; 5. condensate overflow device; 6. tap water storage tank; 7. pesticide wastewater raw water storage tank; 8. flow meter; 9. first pneumatic valve; 10. second pneumatic valve; 11. third pneumatic valve; 12. buffer tank; 13. automatic open-loop control system; 14. water level sensor; 15. agitator; 16. pH probe; 17. first peristaltic pump; 18. heating rod; 19. heat exchanger; 20. second peristaltic pump; 21. temperature sensor; 22. first water inlet; 23. second water inlet; 24. third water inlet; 25. first water inlet valve; 26. second water inlet valve; 27. water outlet; 28. first sampling port; 29. ​​second sampling port; 30. third sampling port; 31. fourth sampling port Sample port; 32, fifth sampling port; 33, sixth sampling port; 34, first mud outlet; 35, second mud outlet; 36, mud pump; 37, third peristaltic pump; 38, mixing pump; 39, membrane pressure gauge; 40, water outlet pump; 41, TOC analyzer; 42, titration sensor; 43, UV spectrometer; 44, FT-IR spectrometer; 45, fourth peristaltic pump; 46, backwash pump; 47, reflux pump; 48, first air chamber; 49, second air chamber; 50, third air chamber; 51, closed pipeline; 52, wet gas flowmeter; 53, gas sensor; 54, gas collection bag; 55, three-phase separator; 56, iron-attached biochar; 57, membrane backwash device; 58, gas collection hood; 59, alkaline detergent; 60, acid detergent; 61, acid storage tank; 62, alkali storage tank; 63 guide plate. DETAILED DESCRIPTION

[0053] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0054] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0055] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0056] In the description of the present application, it should be understood that the terms "center", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0057] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0058] The present invention improves the traditional AnMBR. The buffer tank in the water inlet system is equipped with an automatic open-loop control system, which dilutes the inlet water with tap water and makes the inlet concentration change in a step (the dilution coefficient is between 1 and 4). The anaerobic fermentation part adopts a partitioned UASB reactor, which can cope with the impact of sudden hydraulic conditions on the reactor performance and promote the full mixing of the substrate. In addition, iron-attached biochar is added to the partitioned UASB reactor to provide more living space for microorganisms, promote the interspecies electron transfer rate between microorganisms, speed up the operation of the reactor, and alleviate membrane pollution.

[0059] See also Figure 1 This embodiment provides a pesticide wastewater partitioned anaerobic membrane bioreactor treatment device, comprising:

[0060] Water inlet system, used to dilute and store highly toxic pesticide wastewater;

[0061] The partitioned UASB reactor is internally doped with iron-attached biochar. The present invention converts the discarded Chinese medicine residue into iron-attached biochar, and the concentration of the iron-attached biochar 56 in the partitioned UASB reactor 2 is 5-10 g / L; the water inlet of the partitioned UASB reactor is connected to the water outlet of the water inlet system;

[0062] An external membrane pool is provided with an online monitoring device. The water inlet of the external membrane pool is connected with the water outlet of the partitioned UASB reactor. A mixing pump 38 is provided at the lower part of the external membrane pool. Part of the treated water is discharged through a membrane pressure gauge 39 and a water outlet pump 40. The membrane pressure gauge 39 monitors the change of the transmembrane pressure difference in real time. Another part of the treated water flows to the partitioned UASB reactor 2 through a reflux pump 47 to mix with the sludge to ensure the sludge concentration in the reactor. The online monitoring equipment includes a TOC analyzer 41, a titration sensor 42, a UV spectrometer 43 and a FT-IR spectrometer 44, which are used to measure the indicators in the effluent of the external membrane pool online, including: soluble chemical oxygen demand COD, total organic carbon TOC, total volatile fatty acid VFA, acetate Ac, dissolved CO2, bicarbonate concentration, and total alkalinity and partial alkalinity. The measurement frequency of some indicators is 2-3 times.

[0063] The water outlet pool is connected with a membrane backwashing device; the water inlet of the water outlet pool is connected with the water outlet of the external membrane pool.

[0064] As a preferred implementation provided in this embodiment, Figure 2 As shown, the water inlet system comprises:

[0065] The buffer tank 12 has a volume-adjusting float and a degassing structure, which can be used to eliminate the gas contained in the influent water; the buffer tank is provided with a water level sensor, which is connected to an automatic open-loop control system 13, which dilutes the influent water with tap water and causes a step change in the influent concentration;

[0066] The tap water storage tank 6 is connected to the buffer tank 12 through a flow meter 8 and a first pneumatic valve 9, and the flow meter 8 and the first pneumatic valve 9 are also connected to an automatic open-loop control system 13;

[0067] The pesticide wastewater raw water storage tank 7 is connected to the buffer tank 12 through the second pneumatic valve 10, and the second pneumatic valve 10 is also connected to the automatic open-loop control system 13;

[0068] The water inlet pool 1 has a built-in agitator 15 and a pH probe 16, and a water level sensor is provided on the pool wall; the water inlet pool 1 is connected to the buffer tank 12 through the third pneumatic valve 11, and the pH probe 16, the water level sensor, and the third pneumatic valve 11 are also connected to the automatic open-loop control system 13.

[0069] As a preferred implementation provided in this embodiment, a heat exchanger 19 is provided between the water inlet system and the partitioned UASB reactor 2 to adjust the temperature of the water inlet, and the heat exchanger 19 is connected to the heating rod 18;

[0070] Before the inlet water is heated, it is pumped into the heat exchanger 19 by the first peristaltic pump 17 . After the inlet water is heated, it is pumped to the water inlet of the partitioned UASB reactor 2 by the second peristaltic pump 20 , and the water temperature is monitored online by the temperature sensor 21 .

[0071] As a preferred implementation provided in this example, the partitioned UASB reactor 2 comprises:

[0072] Three digestion chambers are arranged side by side, each of which is provided with a corresponding first air chamber 48, a second air chamber 49, and a third air chamber 50, each of which is connected to a closed pipeline 51; overflow ports are arranged on both sides of each air chamber, such as Figure 6 As shown, the overflow port is connected to the slag removal pipe connected to the sewage pipe. The normal discharge port of the sewage is closed, which will cause the liquid level in the air chamber to rise, thereby overflowing to the slag removal pipe for discharge.

[0073] The water inlet structure has a first water inlet 22, a second water inlet 23, and a third water inlet 24. Figure 3 As shown, the system is a gravity flow distribution system, in which the central water inlet well or water inlet channel overflows into the water inlet tank and is connected to the corresponding digestion chamber top water inlet through a pipe; each water inlet is set to a circular shape, which allows hydraulically balanced individual overflow rates, and the water level has the same height in principle around the entire circumference of the equipment.

[0074] A first water inlet valve 25, arranged before the second water inlet 23;

[0075] A second water inlet valve 26, arranged before the third water inlet 24;

[0076] The water outlet 27 is provided at the top of the reactor side wall, such as Figure 7 As shown, the water outlet and the gas-liquid interface surface are provided with a scum interceptor to prevent the floating sludge from being discharged with the effluent; part of the floating matter is the sludge attached to the biogas bubbles; when these bubbles escape into the atmosphere, the solids will return to the reactor; and the water outlet is connected to the external membrane tank through the third peristaltic pump;

[0077] The sampling system comprises a first sampling port 28, a second sampling port 29, and a third sampling port 30 which are arranged in sequence from bottom to top. A fourth sampling port 31 is arranged on the opposite side of the third sampling port 29, a fifth sampling port 32 is arranged on the opposite side of the second sampling port 29, and a sixth sampling port 33 is arranged on the opposite side of the first sampling port 28. The fourth sampling port, the fifth sampling port, and the sixth sampling port are arranged in sequence from top to bottom.

[0078] The first mud discharge port 34 and the second mud discharge port 35 are arranged at the lower part of the reactor side wall and connected to the mud discharge pipeline, and a mud discharge pump 36 is arranged on the mud discharge pipeline; the mud discharge ports are arranged at different heights to remove heavy inert sludge, low density and inactive sludge; Figure 8As shown, several sludge extraction points are provided, distributed over the surface area of ​​the reactor, allowing the sludge to be extracted from different locations of the reactor. The accumulation of mineral solids at the bottom of the reactor can be avoided by applying a rotating sludge discharge method, and there is no risk of biogas escaping.

[0079] The biogas generated by the partitioned UASB reactor 2 is discharged from the top first air chamber 48, the second air chamber 49, and the third air chamber 50 through a closed pipeline 51. A wet gas flow meter 52 is provided on the closed pipeline to measure the volume of the biogas and a gas sensor 53 is used to measure the composition of the biogas. The discharged biogas passes through a condensate overflow device to keep the liquid level and pressure in the device constant, and is collected in a gas collecting bag 54.

[0080] As a preferred embodiment provided in this example, a three-phase separator 55 is provided on the top of each digestion chamber. Figure 4 As shown, the three-phase separator 55 has a gas collecting hood at the top to guide the generated biogas into a static top settling chamber; the lower part has a gas guide plate to prevent the biogas from entering the settling chamber; the three-phase separator 55 has four main functions: (1) collecting the biogas generated in the digestion zone below the separator. (2) returning the sludge from the lower interface of the separator to the digestion zone after biogas separation. (3) retaining the suspended solids entering the settling zone (above the separator in the upper part of the reactor) and transferring these solids back to the dissolution zone; this allows a large amount of sludge to be maintained in the digestion zone while achieving a low concentration of settleable solids in the effluent. (4) The settling zone above the separator can be used for sludge storage during hydraulic overload without necessarily causing sludge loss. The advantage of the submerged separator is that the entire surface of the reactor can be used for settling, so there is a minimum overflow rate, which increases the possibility that even slowly settling particles may be retained. In addition, due to being submerged, corrosion problems will be reduced because the separator will not be exposed to oxygen in the air, especially where oxygen and water come into contact with the metal.

[0081] like Figure 5 As shown, a layer of scum is usually formed on the interface surface, which makes the biogas outlet easy to be blocked. Therefore, the guide plate is located directly below the gas collecting hood, and only a very small interface is maintained below the guide plate. This can reduce the formation of scum and thus avoid blockage to a large extent.

[0082] As a preferred implementation provided in this embodiment, Fig. 9 As shown, the effluent from the online monitoring equipment enters the effluent pool through the fourth peristaltic pump 45, and the effluent pool is connected back to the external membrane pool through the membrane backwashing device 57 and the backwashing pump 46; the membrane backwashing device 57 adopts a combination of in-situ cleaning CIP and offline cleaning COP;

[0083] The CIP is performed using multiple cycles of backwashing and soaking, each cycle including 1-3 minutes of backwashing and 8-12 minutes of soaking, using NaOCl and NaOH as cleaning agents; followed by 25-35 minutes of pure permeate backwashing to remove cleaning agent residues in pipes and filters; followed by multiple cycles of backwashing and soaking, using citric acid and HCl; CIP is performed every 10-20 days;

[0084] Before the offline cleaning of COP, the membrane is taken out from the external membrane pool, sprayed with water to wash off the attached biomass, and then inserted into the COP pool and soaked with acid cleaning solution or alkaline cleaning solution; the used acid cleaning solution and alkaline cleaning solution are stored in the acid storage tank 61 and the alkali storage tank 62 respectively; the solids and debris are precipitated at the bottom of the pool and then taken out and processed separately; the offline cleaning of COP is carried out every 1.5-2.5 months, and the COP duration varies from 2 to 10 hours depending on the membrane pollution situation. Fig.10 A simplified schematic diagram of the off-line membrane cleaning equipment, including a membrane filtration tank that can accommodate one or several membrane cassettes at a time. A separate blower is installed for air flushing and a backwash pump for cleaning.

[0085] The above-mentioned pesticide wastewater partitioned anaerobic membrane bioreactor treatment device is used as follows: the difficult-to-degrade pesticide wastewater to be treated is mixed with tap water in a certain proportion and then enters the water inlet pool, and the mixed water is added to the partitioned UASB reactor through a heat exchanger. Iron-attached biochar is added to the reactor, and the wastewater is fully reacted within the set residence time, and the remaining sludge will be discharged through the sludge outlet. The wastewater after the reaction is completed flows into the external membrane pool. After the reaction is fully completed, the soluble chemical oxygen demand (COD), total organic carbon (TOC), total volatile fatty acids (VFA), acetate (Ac), dissolved CO2, bicarbonate concentration, and total alkalinity and partial alkalinity in the water are measured by online monitoring equipment, and the remaining sludge in the external membrane pool will flow back to the partitioned UASB reactor. Finally, the treated wastewater is discharged into the effluent pool. To prevent gas leakage during anaerobic digestion, a closed pipeline is set on the top of the partitioned UASB. Due to the cooling of biogas, condensed water will accumulate in the hydraulic seal; therefore, a condensed water overflow device is installed to keep the liquid level and pressure in the gas box constant, and finally collected by the gas collecting bag.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A zoned anaerobic membrane bioreactor treatment device for pesticide wastewater, characterized in that: include: Water inlet system, used to dilute and store highly toxic pesticide wastewater; A partitioned UASB reactor (2) is internally doped with iron-attached biochar (56), and a water inlet of the partitioned UASB reactor is connected to a water outlet of a water inlet system; An external membrane pool (3) is provided with an online monitoring device, and a water inlet of the external membrane pool is connected to a water outlet of the partitioned UASB reactor (2); The water outlet pool (4) is connected to a membrane backwashing device; the water inlet of the water outlet pool is connected to the water outlet of the external membrane pool (3).

2. The pesticide wastewater partitioned anaerobic membrane bioreactor treatment device according to claim 1, characterized in that: The water inlet system comprises: A buffer tank (12) is used to eliminate gas contained in the influent water; the buffer tank is provided with a water level sensor, and the water level sensor is connected to an automatic open-loop control system (13), which dilutes the influent water with tap water and causes a step change in the influent concentration; A tap water storage tank (6) is connected to a buffer tank (12) via a flow meter (8) and a first pneumatic valve (9), and the flow meter (8) and the first pneumatic valve (9) are also connected to an automatic open-loop control system (13); A pesticide wastewater raw water storage tank (7) is connected to a buffer tank (12) via a second pneumatic valve (10), and the second pneumatic valve (10) is also connected to an automatic open-loop control system (13); The water inlet pool (1) has a built-in stirrer (15) and a pH probe (16), and a water level sensor is provided on the pool wall; the water inlet pool (1) is connected to a buffer tank (12) via a third pneumatic valve (11), and the pH probe (16), the water level sensor, and the third pneumatic valve (11) are also connected to an automatic open-loop control system (13).

3. The pesticide wastewater partitioned anaerobic membrane bioreactor treatment device according to claim 1, characterized in that: A heat exchanger (19) is provided between the water inlet system and the zoned UASB reactor (2) for adjusting the temperature of the water inlet, and the heat exchanger (19) is connected to a heating rod (18); Before the incoming water is heated, it is pumped into the heat exchanger (19) by the first peristaltic pump (17). After the incoming water is heated, it is pumped to the water inlet of the partitioned UASB reactor (2) by the second peristaltic pump (20), and the water temperature is monitored online by the temperature sensor (21).

4. The pesticide wastewater partitioned anaerobic membrane bioreactor treatment device according to claim 1, characterized in that: The partitioned UASB reactor (2) comprises: Three digestion chambers are arranged side by side, each of which is provided with a corresponding first air chamber (48), a second air chamber (49), and a third air chamber (50), each of which is connected to a closed pipeline (51), and overflow ports are arranged on both sides of each air chamber, and the overflow ports are connected to a slag removal pipeline; The water inlet structure has a first water inlet (22), a second water inlet (23), and a third water inlet (24), the system being a gravity flow distribution system, wherein a central water inlet well or water inlet channel overflows into a water inlet tank and is connected to the corresponding digestion chamber top water inlet through a pipeline; A first water inlet valve (25) is arranged before the second water inlet (23); A second water inlet valve (26) is arranged before the third water inlet (24); A water outlet (27) is provided at the top of the side wall of the reactor, and a scum trap is provided on the water outlet and the gas-liquid interface surface; A sampling system, comprising a first sampling port (28), a second sampling port (29), and a third sampling port (30) which are arranged in sequence from bottom to top; a fourth sampling port (31) is arranged on the opposite side of the third sampling port (29); a fifth sampling port (32) is arranged on the opposite side of the second sampling port (29); a sixth sampling port (33) is arranged on the opposite side of the first sampling port (28); and the fourth sampling port, the fifth sampling port, and the sixth sampling port are arranged in sequence from top to bottom; The first mud discharge port (34) and the second mud discharge port (35) are arranged at the lower part of the side wall of the reactor and are connected to the mud discharge pipeline, and a mud discharge pump (36) is arranged on the mud discharge pipeline.

5. A zoned anaerobic membrane bioreactor treatment device for pesticide wastewater according to claim 4, characterized in that: A three-phase separator (55) is provided on the top of each digestion chamber. The three-phase separator (55) has a gas collecting hood at the top and a gas guide plate at the bottom. The guide plate is a gradually expanding opening structure.

6. The pesticide wastewater partitioned anaerobic membrane bioreactor treatment device according to claim 1, characterized in that: The discarded Chinese medicine residue is converted into iron-attached biochar, and the concentration of the iron-attached biochar (56) in the partitioned UASB reactor (2) is 5-10 g / L.

7. The pesticide wastewater partitioned anaerobic membrane bioreactor treatment device according to claim 1, characterized in that: A mixing pump (38) is provided at the lower part of the external membrane tank, and part of the treated water is discharged through a membrane pressure gauge (39) and a water outlet pump (40), and the membrane pressure gauge (39) monitors the change of the trans-membrane pressure difference in real time; another part of the treated water flows into the partitioned UASB reactor (2) through a reflux pump (47) to mix with the sludge, thereby ensuring the sludge concentration in the reactor.

8. The pesticide wastewater partitioned anaerobic membrane bioreactor treatment device according to claim 1, characterized in that: The online monitoring equipment includes a TOC analyzer (41), a titration sensor (42), a UV spectrometer (43) and a FT-IR spectrometer (44), which are used to measure online the indicators in the effluent of the external membrane pool, including: soluble chemical oxygen demand COD, total organic carbon TOC, total volatile fatty acids VFA, acetate Ac, dissolved CO2, bicarbonate concentration, and total alkalinity and partial alkalinity.

9. The pesticide wastewater partitioned anaerobic membrane bioreactor treatment device according to claim 1, characterized in that: The biogas generated by the partitioned UASB reactor (2) is discharged from the top first gas chamber (48), the second gas chamber (49), and the third gas chamber (50) through a closed pipeline (51). A wet gas flow meter (52) is provided on the closed pipeline to measure the volume of the biogas, and a gas sensor (53) is used to measure the composition of the biogas. The discharged biogas passes through a condensed water overflow device to keep the liquid level and pressure in the device constant, and is collected in a gas collecting bag (54).

10. The pesticide wastewater partitioned anaerobic membrane bioreactor treatment device according to claim 1, characterized in that: The membrane backwashing device (57) adopts a combination of in-situ cleaning CIP and off-line cleaning COP; The CIP is performed using multiple cycles of backwashing and soaking, each cycle including 1-3 minutes of backwashing and 8-12 minutes of soaking, using NaOCl and NaOH as cleaning agents; followed by 25-35 minutes of pure permeate backwashing to remove cleaning agent residues in pipes and filters; followed by multiple cycles of backwashing and soaking, using citric acid and HCl, and performing CIP every 10-20 days; Before the COP is cleaned offline, the membrane is taken out from the external membrane tank, sprayed with water to wash off the attached biomass, and then inserted into the COP tank and soaked with acid cleaning solution or alkaline cleaning solution; the used acid cleaning solution and alkaline cleaning solution are stored in the acid storage tank (61) and the alkali storage tank (62) respectively; the solids and debris are precipitated at the bottom of the tank and then taken out and processed separately; the COP is cleaned offline every 1.5-2.5 months.

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