A zero-emission system and method for treating high-concentration organic industrial wastewater

Abstract

The present invention discloses a high-concentration organic industrial wastewater treatment system and method with near-zero discharge, including an adjustment tank, a hydrolysis acidification tank, a first-stage anoxic tank, a first-stage aerobic tank, a sewage return well, a middle sedimentation tank, a second-stage anoxic tank, a second-stage aerobic tank, a secondary sedimentation tank, a sump well, a sludge thickening tank, a plate and frame filter press room, a functional organic fertilizer manufacturing room, a blower room, a chemical dosing room, a multi-media filter, an ultrafiltration device, an ultrafiltration water tank, a reverse osmosis lift pump, a security filter, a reverse osmosis high-pressure pump, a reverse osmosis device, an MVR evaporator, a reverse osmosis water tank, and a disinfection and reclaimed water tank. This application achieves near-zero discharge for the treatment of high-concentration organic industrial wastewater. The reclaimed water from the treatment of high-concentration organic industrial wastewater is used for industrial reuse; the concentrated sludge generated during the wastewater treatment process is pressed and improved to manufacture functional organic fertilizers; the evaporation crystallization concentrate after MVR evaporation of the concentrated water generated in the reverse osmosis process of advanced treatment is used for blending in the dehumidification and slag removal section.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of sewage treatment, and specifically provides a high-concentration organic industrial wastewater treatment system and method with near-zero discharge. Background Art

[0002] With the rapid development of industry, the types and quantities of wastewater have increased rapidly, causing increasingly widespread and serious pollution to water bodies, threatening human health and safety.

[0003] High-concentration organic wastewater mainly has the following characteristics: First, the organic matter concentration is high. The COD is generally above 2000 mg / L, and some even reach as high as tens of thousands of mg / L. Relatively speaking, the BOD is lower, and the ratio of BOD to COD in many wastewaters is less than 0.3, making it difficult to treat. Second, the composition is complex. The organic matter in wastewater containing toxic substances mainly consists of aromatic compounds and heterocyclic compounds, and also contains sulfides, nitrides, heavy metals, and toxic organic substances. Third, the chromaticity is high and there is an unpleasant smell. Some wastewaters emit a pungent stench, causing adverse effects on the surrounding environment. Fourth, it has strong acidity or alkalinity. In the ultra-high-concentration organic wastewater generated in industrial processes, there are many acids and alkalis, often with strong acidity or alkalinity.

[0004] The hazards of high-concentration organic wastewater are as follows: First, the toxic hazard. High-concentration organic wastewater contains a large amount of toxic substances, which will accumulate and store in natural environments such as water bodies and soils, and then enter the water bodies and endanger human health. Second, the aerobic hazard. Due to biodegradation, high-concentration organic wastewater will cause the receiving water body to be oxygen-deficient or even anaerobic, and most aquatic organisms will die, resulting in a foul smell and deteriorating water quality and the environment. Third, the sensory pollution. High-concentration organic wastewater not only makes the water body lose its use value, but also seriously affects the normal life of the people nearby. Therefore, economically and effectively treating high-concentration organic industrial wastewater and achieving near-zero discharge has become the focus of research for current water treatment and environmental protection workers. Especially in the face of the reality of the decreasing supply of clean water and rising water prices, in addition to striving to treat the organic wastewater of their own factories up to standard, industrial enterprises should also achieve near-zero discharge and try their best to recycle the clean and up-to-standard water after treatment in their factories.

[0005] In the past treatment of high-concentration organic industrial wastewater, generally, the A / O process was followed by processes such as air flotation, BAF, sand filtration, ozone catalytic oxidation, and fiber filter. Such a process is a stacked process, without being targeted, and the treated water is difficult to meet the standard for reuse, let alone near-zero discharge. Summary of the Invention

[0006] The present invention mainly provides a high-concentration organic industrial wastewater treatment system and method with near-zero discharge to solve the technical problems raised in the above background art.

[0007] The technical solution adopted by the present invention to solve the above technical problems is as follows:

[0008] A zero-discharge system for treating high-concentration organic industrial wastewater, comprising an adjustment tank, a hydrolysis acidification tank, a first-stage anoxic tank, a first-stage aerobic tank, a sewage return well, a middle sedimentation tank, a second-stage anoxic tank, a second-stage aerobic tank, a secondary sedimentation tank, a sump well, a sludge thickening tank, a plate and frame filter press room, a functional organic fertilizer manufacturing room, a blower room, a chemical dosing room, a multi-media filter, an ultrafiltration device, an ultrafiltration water tank, a reverse osmosis lift pump, a security filter, a reverse osmosis high-pressure pump, a reverse osmosis device, an MVR evaporator, a reverse osmosis water tank, and a disinfection and reclaimed water tank. The middle sedimentation tank is located inside the sewage return well.

[0009] Preferably, one side of the adjustment tank is connected to an inlet pipe for connecting with high-concentration organic industrial wastewater. A mechanical grille is arranged inside the adjustment tank, and the mechanical grille is parallel to the adjustment tank. The adjustment tank is connected to an acid liquid tank inside the chemical dosing room through a pH adjustment acid addition pipe. The adjustment tank is connected to the hydrolysis acidification tank through a through-hole in the end wall of the adjustment tank. A bottom air stirring pipe is arranged at the bottom of the hydrolysis acidification tank.

[0010] Preferably, the hydrolysis acidification tank is connected to the first-stage anoxic tank through a through-hole in the end wall of the hydrolysis acidification tank. The first-stage anoxic tank is arranged in a rectangular structure. Bottom push-flow stirrers are arranged at two opposite corners of the first-stage anoxic tank. Elastic three-dimensional denitrification fillers are arranged inside the first-stage anoxic tank. A first-stage nitrification liquid return pipe is arranged inside one end of the first-stage anoxic tank. A nitrification liquid return pump is arranged at the bottom of the sewage return well. The first-stage nitrification liquid return pipe is connected to the nitrification liquid return pump. A sludge return pipe is arranged inside the other end of the first-stage anoxic tank. A sludge return pump is arranged at the bottom of the middle sedimentation tank. The sludge return pipe is connected to the sludge return pump.

[0011] Preferably, the first-stage anoxic tank is connected to the first-stage aerobic tank through a through-hole in the end wall of the first-stage anoxic tank. Aeration components and an air inlet pipe and an alkali liquid dosing pipe are arranged at the bottom of the first-stage aerobic tank. Polyurethane high-efficiency biological carrier fillers are arranged in the first-stage aerobic tank. The alkali liquid dosing pipe is connected to an alkali liquid tank inside the chemical dosing room.

[0012] Preferably, the first-stage aerobic tank is connected to the sewage return well through a through-hole in the end wall of the first-stage aerobic tank. A nitrification liquid return pump is arranged inside the sewage return well. The nitrification liquid return pump is connected to the first-stage nitrification liquid return pipe.

[0013] Preferably, the intermediate sedimentation tank is located inside the sewage return well. The intermediate sedimentation tank is connected to the secondary anoxic tank through the communication hole in the end wall of the intermediate sedimentation tank. A sludge return pump is provided inside the intermediate sedimentation tank, and the sludge return pump is connected to the sludge return pipe. Two of the opposite corners of the secondary anoxic tank are provided with bottom-pushing agitators. A combined denitrification filler is arranged in the secondary anoxic tank. A secondary nitrification liquid return pipe and an external carbon source inlet pipe are arranged inside one end of the secondary anoxic tank. An external carbon source dosing tank is arranged outside the secondary anoxic tank. A secondary nitrification liquid return pump is provided inside the secondary aerobic tank, and the secondary nitrification liquid return pipe is connected to the secondary nitrification liquid return pump. An external carbon source solution tank is arranged inside the chemical dosing room, and the external carbon source solution tank is connected to the external carbon source inlet pipe. The secondary anoxic tank is connected to the secondary aerobic tank through the communication hole in the end wall of the secondary anoxic tank. A bottom aeration pipe assembly and a bottom aeration pipe inlet pipe are arranged at the bottom of the secondary aerobic tank.

[0014] Preferably, the secondary aerobic tank is connected to the secondary sedimentation tank through the connecting hole in the end wall of the secondary aerobic tank. An inclined tube assembly is arranged inside the secondary sedimentation tank. The secondary sedimentation tank is connected to the collecting well through the upper connecting hole in the end wall of the secondary sedimentation tank. The secondary sedimentation tank is connected to the sludge thickening tank through the lower connecting hole in the end wall of the secondary sedimentation tank. A collecting well lift pump and a pressure water pipe of the collecting well lift pump are arranged inside the collecting well. The collecting well lift pump is connected to the inlet water pipe on one side of the top of the multi-media filter through the pressure water pipe of the collecting well lift pump. A multi-media filtering layer is arranged inside the multi-media filter. A multi-media filter outlet pipe is arranged at the bottom of the multi-media filter. The multi-media filter outlet pipe is connected to the inlet water pipe on one side of the bottom of the ultrafiltration device. An ultrafiltration device outlet pipe is arranged on one side of the top of the ultrafiltration device. An ultrafiltration backwash pump is arranged inside the ultrafiltration water tank. An ultrafiltration backwash pump pressure water pipe is connected to the ultrafiltration backwash pump. The ultrafiltration device outlet pipe is connected to the ultrafiltration backwash pump pressure water pipe. One side of the reverse osmosis lift pump is connected with a reverse osmosis lift pump suction pipe, and the other side is connected with a reverse osmosis lift pump pressure water pipe. The reverse osmosis lift pump suction pipe is connected to the ultrafiltration water tank. The reverse osmosis lift pump pressure water pipe is connected to the reverse osmosis high-pressure pump suction pipe connected to one side of the security filter. The other side of the security filter is connected with a security filter outlet pipe at the bottom. One side of the reverse osmosis high-pressure pump is connected with a reverse osmosis high-pressure pump suction pipe, and the other side is connected with a reverse osmosis high-pressure pump pressure water pipe. The security filter outlet pipe is connected to the reverse osmosis high-pressure pump suction pipe. The reverse osmosis high-pressure pump pressure water pipe is connected to the reverse osmosis device inlet pipe connected to one side of the reverse osmosis device. A cleaning agent dosing tank and a scale inhibitor dosing tank are connected between the security filter outlet pipe and the reverse osmosis device inlet pipe. One side of the reverse osmosis device is connected with a reverse osmosis device product water pipe connected to the reverse osmosis water tank.

[0015] Preferably, the reverse osmosis water tank is connected to the disinfection and recycled water tank through the connecting hole in the end wall of the reverse osmosis water tank. A disinfection device is connected to the disinfection and recycled water tank. A recycled water pump is connected to the side of the disinfection and recycled water tank away from the reverse osmosis water tank through a recycled water pump suction pipe. The other side of the recycled water pump is connected with a recycled water pump pressure water pipe.

[0016] According to a zero-discharge system for treating high-concentration organic industrial wastewater, a zero-discharge method for treating high-concentration organic industrial wastewater will also be provided, including the following steps:

[0017] Step 1: The high-concentration organic industrial wastewater enters the regulating tank through the inlet pipe. After removing slag by the mechanical grille, the pH is adjusted. Dilute sulfuric acid solution is added to the regulating tank through the acid liquid tank arranged in the chemical dosing room and the pH-adjusting acid adding pipe connected thereto to adjust the pH to 7-8. The residence time in the regulating tank is 12h.

[0018] The treated water with adjusted water quality and quantity flows into the hydrolysis acidification tank through the connecting holes on the end wall of the regulating tank for hydrolysis and acidification, two-stage facultative microbial reactions. The air stirring pipes at the bottom of the tank are turned on once every 4 hours for 20 minutes each time to provide and maintain a dissolved oxygen of 0.3 - 0.5 mg / L in the hydrolysis acidification tank. The residence time of the hydrolysis acidification tank is 8 hours;

[0019] The effluent from the hydrolysis acidification tank enters the first-stage anoxic tank through the connecting holes on the end wall of the hydrolysis acidification tank. The bottom diagonal flow agitator in the tank provides the 0.5 - 1 mg / L dissolved oxygen required for denitrification. The biofilm attached to the elastic three-dimensional denitrification filler installed in the tank forms a micro A / O unit. The existence of an anoxic microenvironment inside the biofilm helps the denitrification reaction proceed. The treated wastewater in the first-stage anoxic tank is mixed with the nitrification liquid provided by the nitrification liquid reflux pump installed at the bottom of the sewage reflux well and the connected first-stage nitrification liquid reflux pipe, and the first-stage microbial denitrification reaction is completed. NOx--N is converted into N2 and escapes from the wastewater, and the nitro-oxidized organic matter is utilized. The nitrification liquid reflux ratio R = 3 - 4. The surplus sludge is refluxed by the sludge reflux pump installed at the bottom of the intermediate sedimentation tank and the connected sludge reflux pipe for phosphorus release. The sludge reflux ratio r = 1. The denitrification load of the first-stage anoxic tank is 0.14 kgNOx--N / kgMLSS·d;

[0020] The effluent from the first-stage anoxic tank enters the first-stage aerobic tank through the connecting holes on the end wall of the first-stage anoxic tank. The bottom aerator assembly and the air inlet pipe of the bottom aerator assembly installed at the bottom of the tank provide the 2 - 4 mg / L dissolved oxygen required for nitrification. When PH ≤ 6.3, Na2CO3 alkaline solution is added by the alkaline solution tank installed in the chemical dosing room and the connected alkaline solution dosing pipe to maintain PH 7 - 8. The nitrification load of the first-stage aerobic tank is 0.10 kgNH3-N / kgMLSS·d;

[0021] The effluent from the first-stage aerobic tank enters the sewage reflux well through the connecting holes on the end wall of the first-stage aerobic tank. Part of it is transported by the nitrification liquid reflux pump installed at the bottom of the tank and the connected first-stage nitrification liquid reflux pipe to the first-stage anoxic tank to mix the nitrification liquid containing nitrite bacteria and nitrate bacteria with the treated water in the tank for denitrification and nitrogen removal. The other part enters the intermediate sedimentation tank, and the inclined plate assembly separates the sludge and water from the effluent after the treatment of the first-stage anoxic tank / first-stage aerobic tank process. The water after sludge and water separation enters the second-stage anoxic tank through the connecting holes on the end wall of the intermediate sedimentation tank. The surplus sludge after sludge and water separation enters the first-stage anoxic tank through the sludge reflux pump and the connected sludge reflux pipe. The surface load of the intermediate sedimentation tank is 1.2 m³ / (㎡·h);

[0022] The above-mentioned primary denitrification, phosphorus removal, and organic matter removal are carried out through the primary anoxic tank / primary aerobic tank process. After treatment in the primary anoxic tank / primary aerobic tank, the effluent COD is about 100 mg / L, and TN is 60 mg / L, mainly nitrate nitrogen. Therefore, the secondary anoxic tank / secondary aerobic tank process is required for treatment;

[0023] In the secondary anoxic tank, the dissolved oxygen required for the microbial denitrification reaction is provided by the bottom-pushing agitator installed diagonally at the bottom of the tank, which is 0.5 - 1 mg / L. The combined denitrification packing installed in the tank can provide a sufficient and stable microbial flora after biofilm formation. Moreover, due to the unity and sealing of the biofilm, the aerobic, anoxic, and anaerobic synergistic effects are naturally formed due to the different oxygen concentrations received by the surface, middle, and inner layers of the membrane body, realizing the simultaneous nitrification-denitrification reaction to improve the denitrification and phosphorus removal effects. The treated wastewater in the secondary anoxic tank is mixed with the reflux nitrification liquid provided by the secondary nitrification liquid reflux pump installed in the secondary aerobic tank and the connected secondary nitrification liquid reflux pipe. Since the total nitrogen in the effluent after passing through the primary anoxic tank / primary aerobic tank is still about 60 mg / L and mainly nitrate nitrogen; although the COD effluent is about 100 mg / L, its biodegradability is poor. Therefore, an additional carbon source needs to be supplemented to enhance the denitrification effect. The additional carbon source is a high-quality plant carbon source, and the dosage is 1 g / h·L. The additional carbon source is added by the additional carbon source solution tank installed in the chemical dosing room, the connected additional carbon source inlet pipe, and the additional carbon source dosing tank. Under the condition of sufficient carbon source, the secondary microbial denitrification reaction is completed, further converting NOx--N into N2 and escaping from the wastewater, and further oxidizing organic matter with nitrite. The nitrification liquid reflux ratio R = 2 - 3, and the denitrification load of the secondary anoxic tank is 0.12 kgNH3-N / kgMLSS·d;

[0024] The effluent from the secondary anoxic tank enters the secondary aerobic tank through the connecting holes in the end wall of the secondary anoxic tank. The dissolved oxygen required for the secondary nitrification reaction is provided by the bottom aeration pipe assembly installed at the bottom of the tank and the bottom aeration pipe inlet pipe, which is 1 - 2 mg / L. In the secondary aerobic tank, organic matter is first oxidized during nitrification, and then ammonium is oxidized. Nitritation and nitrification are carried out in series. The air-water ratio of the secondary aerobic tank is 20:1, and the average membrane flux is 20 L / h·㎡. The nitrification load of the secondary aerobic tank is 0.08 kgNH3--N / kgMLSS·d;

[0025] The above-mentioned denitrification, phosphorus removal, and removal of organic pollutants are carried out through the secondary anoxic tank / secondary aerobic tank process;

[0026] The effluent from the secondary aerobic tank enters the secondary sedimentation tank through the bottom connecting through-hole of the end pool wall of the secondary aerobic tank. The effluent after the treatment of the secondary anoxic tank / secondary aerobic tank process is separated into sludge and water by the inclined tube assembly. The water after the sludge-water separation enters the collecting well through the upper connecting hole of the end pool wall of the secondary sedimentation tank, and the surplus sludge after the sludge-water separation enters the sludge thickening tank through the lower part of the end pool wall of the secondary sedimentation tank. The surface loading of the secondary sedimentation tank is 1.0 m³ / (㎡·h). After the treatment of the secondary anoxic tank / secondary aerobic tank, the effluent COD is about 50 mg / L, ammonia nitrogen is about 1 mg / L, total nitrogen is about 15 mg / L, and phosphorus is about 0.5 mg / L, reaching the first-class A standard of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants (GB18919-2002);

[0027] The treated water in the transfer collecting well enters the multi-media filter through the collecting well lift pump and the collecting well lift pump pressure pipe arranged at the bottom of the tank and the multi-media filter inlet pipe connected thereto. It is filtered by the composite multi-media filter layer to intercept and remove suspended solids and other impurities in the water. The filtration rate of the multi-media filter is 4-5 m / h;

[0028] The effluent of the multi-media filter enters the ultrafiltration device through the multi-media filter outlet pipe at the bottom of the multi-media filter and the ultrafiltration device inlet pipe at the bottom of the ultrafiltration device connected thereto, intercepting macromolecular substances with a diameter of 0.01-0.1 μm to meet the water quality requirements of the reverse osmosis membrane inlet water. The ultrafiltration device needs to be backwashed every 1 h of operation. The backwash water is provided by the ultrafiltration backwash pump and the ultrafiltration backwash pump pressure pipe arranged at the bottom of the ultrafiltration water tank. The static pressure of the ultrafiltration device is 0.1-0.5 MPa;

[0029] The effluent of the ultrafiltration device enters the ultrafiltration water tank through the ultrafiltration device outlet pipe arranged at the upper part, and then is lifted to the security filter by the reverse osmosis lift pump suction pipe, the reverse osmosis lift pump, and the reverse osmosis lift pump pressure pipe for filtration by the polypropylene PP melt-blown filter element to intercept and remove particles between 0.03-100 μm to protect the subsequent process reverse osmosis membrane;

[0030] The effluent of the security filter enters the reverse osmosis device through the security filter outlet pipe arranged at the lower part, the reverse osmosis high-pressure pump suction pipe, the reverse osmosis high-pressure pump, the reverse osmosis high-pressure pump pressure pipe, and the reverse osmosis device inlet pipe at the upper part of the head end of the reverse osmosis device, intercepting small molecule solutes, organic impurities, and dissolved inorganic salts with a component size of 1-10 Å. When the membrane flux drops by 10%-15% and the conductivity of the permeated water increases by 5%-10%, the reverse osmosis membrane needs to be cleaned. The cleaning agent is MCT410, which is added through the cleaning agent dosing tank, and the scale inhibitor is EWT620, which is added through the scale inhibitor dosing tank. The water treated by the reverse osmosis device enters the reverse osmosis water tank through the reverse osmosis device product water pipe arranged at the end of the reverse osmosis device. The reverse osmosis device uses an aromatic polyamide membrane, with a designed flux of 20.0 L / (㎡·h) and an operating pressure of 1.55 MPa,

[0031] The effluent from the reverse osmosis water tank enters the disinfection and recycled water tank through the connecting holes in the end pool wall of the reverse osmosis water tank, and is disinfected by the disinfection equipment. After the effluent meets the water quality standards for industrial water reuse or industrial cooling circulating water, it is connected to the internal industrial water pipe network of the factory through the suction pipe of the recycled water pump, the recycled water pump, and the pressure pipe of the recycled water pump;

[0032] Step 2: The remaining sludge separated from the sludge and water in the secondary sedimentation tank enters the sludge thickening tank through the connecting holes at the bottom of the end of the secondary sedimentation tank. The residence time in the sludge thickening tank is 16h. The thickened sludge is transported to the plate and frame filter press through the sludge suction pipe of the screw pump and the screw pump installed in the plate and frame filter press room for pressing to a sludge with a moisture content of 70 - 75%. The pressed sludge is sent to the mixing and stirring machine installed in the functional organic fertilizer manufacturing room by the conveyor belt and heavy metal composite stabilizer and sludge conditioner are added. The heavy metal composite stabilizer consists of 50% fly ash, 16.7% ferric chloride, 16.7% polyaluminum sulfate, and 16.6% formamide, and the dosage is 0.02kg / m³ of sludge. The sludge conditioner consists of organic carbon bacteria liquid and enzyme, and the dosages are 3kg / m³ and 0.01kg / m³ of sludge respectively. After mixing and stirring for 5 minutes, it is transported to a small and fast composting machine and made into functional organic fertilizer with a particle size of 1.0 - 2.0mm through processes such as fermentation, and finally packaged by the screening and packaging machine;

[0033] Step 3: The method is that the concentrated water generated by the reverse osmosis process for the advanced treatment of water is used for the dehumidification and slag removal section after MVR evaporation;

[0034] The concentrated water generated during the water treatment process by the reverse osmosis device enters the MVR evaporator through the concentrated water pipe of the reverse osmosis device and the liquid inlet pipe connected thereto for evaporation and crystallization treatment. The condensed water generated during the evaporation and crystallization process enters the multi-media filter through the condensed water pipe and the multi-media filter inlet pipe connected thereto. The evaporation and crystallization concentrate is discharged through the concentrate discharge pipe for the dehumidification and slag removal section.

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] This application aims for zero discharge in the treatment of high-concentration organic industrial wastewater. The reclaimed water from the treatment of high-concentration organic industrial wastewater is used for industrial reuse; the concentrated sludge generated during the wastewater treatment process is made into functional organic fertilizer (soilless cultivation substrate) after pressing and improvement; the evaporation and crystallization concentrate after MVR evaporation of the concentrated water generated by the advanced treatment reverse osmosis process is used for blending in the dehumidification and slag removal section. In addition, the secondary A / O process is adopted during the wastewater treatment process and carbon sources are supplemented in the secondary anoxic tank, which can more reasonably distribute carbon sources and reduce investment and operating costs.

[0037] The following will explain the present invention in detail in combination with the drawings and specific embodiments. Brief Description of the Drawings

[0038] Figure 1 It is a schematic plan view and a relational diagram of the composition of the present invention;

[0039] Figure 2 It is a schematic plan view and a flowchart of the composition of the present invention;

[0040] Figure 3 It is a three-dimensional schematic view of the present invention;

[0041] Figure 4 It is a detailed three-dimensional schematic view of the present invention.

[0042] Description of the drawings: 1. Regulation tank; 1-1. Inlet pipe; 1-2. Mechanical grille; 1-3. pH regulation acid addition pipe; 2. Hydrolysis acidification tank; 2-1. Air agitation pipe at the bottom of the tank; 2-2. Inlet pipe of the air agitation pipe at the bottom of the tank; 3. First-stage anoxic tank; 3-1. Bottom-pushing agitator; 3-2. Elastic three-dimensional denitrification filler; 3-3. First-stage nitrification liquid return pipe; 3-4. Sludge return pipe; 4. First-stage aerobic tank; 4-1. Aerator assembly at the bottom of the tank; 4-2. Inlet pipe of the aerator assembly at the bottom of the tank; 4-3. Polyurethane high-efficiency biological carrier filler; 4-4. Alkali solution dosing pipe; 5. Sewage return well; 5-1. Nitrification liquid return pipe; 6. Intermediate sedimentation tank; 6-1. Sludge return pump; 6-2. Inclined plate assembly; 7. Second-stage anoxic tank; 7-1. Bottom-pushing agitator; 7-2. Combined denitrification filler; 7-3. Second-stage nitrification liquid return pipe; 7-4. External carbon source inlet pipe; 7-5. External carbon source dosing tank; 8. Second-stage aerobic tank; 8-1. Aeration pipe assembly at the bottom of the tank; 8-2. Inlet pipe of the aeration pipe assembly at the bottom of the tank; 8-3. MBR membrane assembly; 8-4. Second-stage nitrification liquid return pump; 9. Secondary sedimentation tank; 9-1. Inclined tube assembly; 10. Sump; 10-1. Sump lift pump; 10-2. Pressure pipe of the sump lift pump; 11. Sludge thickening tank; 11-1. Screw pump suction pipe; 12. Plate and frame filter press room; 12-1. Screw pump; 12-2. Plate and frame filter press; 13. Functional organic fertilizer manufacturing room; 13-1. Mixing blender; 13-2. Small and fast composting machine; 13-3. Screening and packaging machine; 14. Blower room; 14-1. Blower; 15. Chemical dosing room; 15-1. Alkali solution tank; 15-2. External carbon source solution tank; 15-3. Acid solution tank; 16. Multi-media filter; 16-1. Inlet pipe of the multi-media filter; 16-2. Outlet pipe of the multi-media filter; 16-3. Composite multi-media filter layer; 17. Ultrafiltration device; 17-1. Inlet pipe of the ultrafiltration device; 17-2. Outlet pipe of the ultrafiltration device; 18. Ultrafiltration water tank; 18-2. Ultrafiltration backwash pump; 18-21. Pressure pipe of the ultrafiltration backwash pump; 19. Reverse osmosis lift pump; 19-1. Suction pipe of the reverse osmosis lift pump; 19-2. Pressure pipe of the reverse osmosis lift pump; 20. Security filter; 20-2. Outlet pipe of the security filter; 21. Reverse osmosis high-pressure pump; 21-1. Suction pipe of the reverse osmosis high-pressure pump; 21-2. Pressure pipe of the reverse osmosis high-pressure pump; 22. Reverse osmosis device; 22-1. Inlet pipe of the reverse osmosis device; 22-2. Product water pipe of the reverse osmosis device; 22-3. Concentrate pipe of the reverse osmosis device; 22-4. Cleaning agent dosing tank; 22-5. Scale inhibitor dosing tank; 23. MVR evaporator; 23-1. Inlet pipe of the MVR evaporator; 23-2. Concentrate discharge pipe; 23-3. Condensate pipe; 24. Reverse osmosis water tank; 25. Disinfection and recycled water tank; 25-1. Disinfection equipment; 25-2. Recycled water pump; 25-21. Suction pipe of the recycled water pump; 25-22. Pressure pipe of the recycled water pump. Detailed Implementation Modes

[0043] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in different forms and is not limited to the embodiments described in the text. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0044] It should be noted that when an element is referred to as "fixedly provided on" another element, it can be directly on the other element or there may be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used in this article are only for the purpose of illustration.

[0045] Unless otherwise defined, all technical and scientific terms used in this article have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the specification of the present invention in this article are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in this article includes any and all combinations of one or more of the related listed items.

[0046] In this embodiment, the hydraulic circulation of each unit is communicated through the hole communication holes reserved at the ends of each pool wall. Embodiment

[0047] Please refer specifically to the attached Figures 1-4As shown in the figure, a high-concentration organic industrial wastewater treatment system with near-zero discharge includes an adjustment tank 1, a hydrolysis acidification tank 2, a first-stage anoxic tank 3, a first-stage aerobic tank 4, a sewage return well 5, an intermediate sedimentation tank 6, a second-stage anoxic tank 7, a second-stage aerobic tank 8, a secondary sedimentation tank 9, a collecting well 10, a sludge thickening tank 11, a plate and frame filter press room 12, a functional organic fertilizer manufacturing room 13, a blower room 14, a chemical dosing room 15, a multi-media filter 16, an ultrafiltration device 17, an ultrafiltration water tank 18, a reverse osmosis lift pump 19, a security filter 20, a reverse osmosis high-pressure pump 21, a reverse osmosis device 22, an MVR evaporator 23, a reverse osmosis water tank 24, and a disinfection and reclaimed water tank 25. The hydraulic circulation of each of the above units is connected and circulated through the hole communication holes reserved at the ends of each pool wall. The intermediate sedimentation tank 6 is located inside the sewage return well 5. One side of the adjustment tank 1 is connected to a water inlet pipe 1-1 for connecting with high-concentration organic industrial wastewater. A mechanical grille 1-2 is arranged inside the adjustment tank 1. The function of the adjustment tank 1 is to collect wastewater, adjust the pH, and play a role in adjusting the water volume and water quality. The mechanical grille 1-2 is parallel to the adjustment tank 1. The adjustment tank 1 is connected to an acid liquid tank 15-3 inside the chemical dosing room 15 through a pH adjustment acid addition pipe 1-3. The adjustment tank 1 is connected to the hydrolysis acidification tank 2 through a communication hole in the end pool wall of the adjustment tank 1. A bottom air stirring pipe 2-1 is arranged at the bottom of the hydrolysis acidification tank 2. The inlet pipe of the bottom air stirring pipe 2-1 is connected to an air delivery pipe arranged in the blower room 14. The function of the hydrolysis acidification tank 2 is to decompose the macromolecular organic matter that is difficult to biodegrade in the wastewater into small molecular organic matter that is easy to biodegrade through anaerobic hydrolysis, and further improve the biodegradability of the organic wastewater. The hydrolysis acidification tank 2 is connected to the first-stage anoxic tank 3 through a communication hole in the end pool wall of the hydrolysis acidification tank 2. The first-stage anoxic tank 3 is arranged in a rectangular structure. Two of the four corners of the first-stage anoxic tank 3 are provided with bottom push-flow stirrers 3-1. The push-flow stirrers are low-speed push-flow stirrers with a rotation speed of 47 r / min. Elastic three-dimensional denitrification fillers 3-2 are arranged inside the first-stage anoxic tank 3. The diameter of the filler unit is 173 mm, the wire diameter is 0.5 mm, and the specific surface area is 300 ㎡ / m³. A first-stage nitrification liquid return pipe 3-3 is arranged inside one end of the first-stage anoxic tank 3. A nitrification liquid return pump 5-1 is arranged at the bottom of the sewage return well 5. The first-stage nitrification liquid return pipe 3-3 is connected to the nitrification liquid return pump 5-1. A sludge return pipe 3-4 is arranged inside the other end of the first-stage anoxic tank 3. A sludge return pump 6-1 is arranged at the inner bottom of the intermediate sedimentation tank 6. The sludge return pipe 3-4 is connected to the sludge return pump 6-1. The function of the first-stage anoxic tank 3 is to carry out first-stage denitrification, nitrogen and phosphorus removal, and remove part of the organic pollutants. The first-stage anoxic tank 3 is connected to the first-stage aerobic tank 4 through a communication hole in the end pool wall of the first-stage anoxic tank 3. A bottom aerator assembly 4-1, an inlet pipe of the bottom aerator assembly 4-2, and an alkali liquid dosing pipe 4-4 are arranged at the bottom of the first-stage aerobic tank 4. The aerator is a disc-type microporous aerator with a service area of 0.5 ㎡ / unit, an air supply volume of 2 m³ / h·unit, and an oxygen utilization rate of 20%.The air inlet pipe of the bottom aerator assembly in the pond is connected to the air delivery pipe of the blower. In the first-stage aerobic pond 4, there is a polyurethane high-efficiency biological carrier filler 4-3. This filler is a 20-mm cube with a specific surface area of 4000 ㎡ / m³, and the dosing ratio is 30% of the pond volume. The lye dosing pipe 4-4 is connected to the lye tank 15-1 inside the chemical dosing room 15. The function of the first-stage aerobic pond 4 is first-stage nitrification, removal of organic pollutants, and phosphorus absorption. The first-stage aerobic pond 4 is connected to the sewage return well 5 through the communication hole in the end wall of the pond. Inside the sewage return well 5, there is a nitrification liquid return pump 5-1, and the nitrification liquid return pump 5-1 is connected to the first-stage nitrification liquid return pipe 3-3. The function of the sewage return well 5 is to receive the effluent treated by the A1 / O1 process. The intermediate sedimentation tank 6 is located inside the sewage return well 5. The intermediate sedimentation tank 6 is connected to the second-stage anoxic pond 7 through the communication hole in the end wall of the intermediate sedimentation tank 6. Inside the intermediate sedimentation tank 6, there is a sludge return pump 6-1. In the pond, there is an inclined plate assembly. The inclined plates are small-spacing inclined plates with a plate spacing of 60 mm, a block size of 1000×1000×1000 (mm), and an installation inclination angle of 63°. The function of the intermediate sedimentation tank 6 is to separate mud and water from the effluent treated by the A1 / O1 process. The sludge return pump 6-1 is connected to the sludge return pipe 3-4. In the second-stage anoxic pond 7, two bottom-pushing mixers 7-1 are set at two opposite corners. This pushing mixer 7-1 is a low-speed pushing mixer with a rotation speed of 38 r / min. In the second-stage anoxic pond 7, there is a combined denitrification filler 7-2. The diameter of a single piece of this filler is 150 mm, the spacing between single pieces is 80 mm, and the specific surface area is 2000 ㎡ / m³. Inside one end of the second-stage anoxic pond 7, there are a second-stage nitrification liquid return pipe 7-3 and an external carbon source inlet pipe 7-4. Outside the second-stage anoxic pond 7, there is an external carbon source dosing tank 7-5. The function of the second-stage anoxic pond 7 is second-stage denitrification and phosphorus removal, and further removal of organic pollutants. Inside the second-stage aerobic pond 8, there is a second-stage nitrification liquid return pump 8-4. The second-stage nitrification liquid return pipe 7-3 is connected to the second-stage nitrification liquid return pump 8-4. Inside the chemical dosing room 15, there is an external carbon source solution tank 15-2, and the external carbon source solution tank 15-2 is connected to the external carbon source inlet pipe 7-4. The second-stage anoxic pond 7 is connected to the second-stage aerobic pond 8 through the communication hole in the end wall of the second-stage anoxic pond 7. At the bottom of the second-stage aerobic pond 8, there is a bottom aeration pipe assembly 8-1 and a bottom aeration pipe inlet 8-2. This aeration pipe is a tubular microporous aerator with an air supply of 8.0 m³ / m·h and an oxygen utilization rate of 29%. The inlet pipe of the bottom aeration pipe assembly is connected to the air delivery pipe of the blower. In the pond, there is an MBR membrane module 8-3. The MBR membrane filtration form is negative pressure suction (submerged flat membrane module). At the bottom of the end, there is a second-stage nitrification liquid return pump 8-4. The function of the second-stage aerobic pond 8 is second-stage nitrification, further removal of organic pollutants, and phosphorus absorption. The second-stage aerobic pond 8 is connected to the secondary sedimentation tank 9 through the communication hole in the end wall of the second-stage aerobic pond 8. Inside the secondary sedimentation tank 9, there is an inclined tube assembly 9-1, and the diameter of the inclined tube is 80 mm.The block size is 1000×1000×1000 (mm), and the installation inclination angle is 60°. The function of the secondary sedimentation tank is to receive the effluent treated by the A2 / O2 process and separate the sludge from the water. The secondary sedimentation tank 9 is connected to the collecting well 10 through the upper connecting hole on the end wall of the secondary sedimentation tank 9. The secondary sedimentation tank 9 is connected to the sludge thickening tank 11 through the lower connecting hole on the end wall of the secondary sedimentation tank 9. Inside the collecting well 10, there are a collecting well lift pump 10-1 and a collecting well lift pump pressure water pipe 10-2. The function of the collecting well 10 is to transfer the water separated from the sludge and water in the secondary sedimentation tank 9. The screw pump suction pipe 11-1 installed in the sludge thickening tank 11 is connected to the screw pump 12-1 installed in the plate and frame filter press room 12. The function of the sludge thickening tank 11 is to thicken the sludge generated during the wastewater treatment process and increase the solid content rate of the sludge. Inside the plate and frame filter press room 12, there are a screw pump 12-1 and a plate and frame filter press 12-2. The function of the plate and frame filter press 12 is to dehydrate the thickened sludge to about 75%. Inside the functional organic fertilizer manufacturing room 13, there are a mixing and stirring machine 13-1, a small and fast composting machine 13-2, and a screening and packaging machine 13-3. The function of the functional organic fertilizer manufacturing room 13 is to manufacture functional organic fertilizers after improving the filtered sludge. The collecting well lift pump 10-1 is connected to the multi-media filter inlet pipe 16-1 on one side of the top of the multi-media filter 16 through the collecting well lift pump pressure water pipe 10-2. Inside the multi-media filter 16, there is a multi-media filter layer 16-3. The multi-media filter layer 16-3 is composed of emery, medical stone, and fruit shell activated carbon, with each accounting for 1:1:1, a particle size of 1-2 mm, and a filter layer thickness of 1200 mm. At the bottom of the multi-media filter 16, there is a multi-media filter outlet pipe 16-2. The function of the multi-media filter 16 is to intercept and treat suspended solids and other impurities in the water through the composite multi-media filter material. The multi-media filter outlet pipe 16-2 is connected to the ultrafiltration device inlet pipe 17-1 on one side of the bottom of the ultrafiltration device 17. The ultrafiltration device 17 is of the internal pressure type, and the membrane material is polypropylene PP. On one side of the top of the ultrafiltration device 17, there is an ultrafiltration device outlet pipe 17-2. The function of the ultrafiltration device 17 is to further remove suspended solids, particulate matter, biological pollutants, colloids, bacteria, and macromolecular organic matter in the treated water to meet the water quality requirements for the reverse osmosis membrane inlet. Inside the ultrafiltration water tank 18, there is an ultrafiltration backwash pump 18-2. The ultrafiltration backwash pump pressure water pipe 18-21 is connected to the ultrafiltration backwash pump 18-2. The ultrafiltration device outlet pipe 17-2 is connected to the ultrafiltration backwash pump pressure water pipe 18-21 and is switched according to different uses during operation. One side of the reverse osmosis lift pump 19 is connected to a reverse osmosis lift pump suction pipe 19-1, and the other side is connected to a reverse osmosis lift pump pressure water pipe 19-2. The reverse osmosis lift pump suction pipe 19-1 is connected to the ultrafiltration water tank 18. The reverse osmosis lift pump pressure water pipe 19-2 is connected to the reverse osmosis high-pressure pump suction pipe 21-1 connected to one side of the security filter 20. The other side of the security filter 20 is connected to a security filter outlet pipe 20-2 at the bottom,The security filter 20 uses polypropylene PP melt-blown filter elements. The function of the security filter 20 is to protect the reverse osmosis membrane from being damaged by the filtered substances that occasionally pass through the pretreatment system. One side of the reverse osmosis high-pressure pump 21 is connected with a reverse osmosis high-pressure pump suction pipe 21-1. The pressure of the reverse osmosis high-pressure pump 21 is 1.4 - 5 MPa. The other side of the reverse osmosis high-pressure pump 21 is connected with a reverse osmosis high-pressure pump pressure pipe 21-2. The security filter outlet pipe 20-2 is connected with the reverse osmosis high-pressure pump suction pipe 21-1. The reverse osmosis high-pressure pump pressure pipe 21-2 is connected with a reverse osmosis device inlet pipe 22-1 connected to one side of the reverse osmosis device 22. The reverse osmosis device 22 uses an aromatic polyamide composite membrane, and the filtered and retained components are small molecule solutes with a size of 1 - 10 Å, etc. The operating pressure is 1.55 MPa. Before the security filter outlet pipe 20-2 and the reverse osmosis device inlet pipe 22-1, there are a cleaning agent dosing tank 22-4 and a scale inhibitor dosing tank 22-5 connected. One side of the reverse osmosis device 22 is connected with a reverse osmosis device product water pipe 22-2 connected to the reverse osmosis water tank 24. The function of the reverse osmosis device 22 is to further remove suspended solids and colloids in the treated water, control the growth of microorganisms, inhibit and control the deposition of slightly soluble salts, remove organic matter, control the precipitation of heavy metal oxides and silicon, so that the effluent meets the industrial water reuse or industrial cooling circulating water quality standards. The reverse osmosis water tank 24 is connected with the disinfection and reused water tank 25 through the connecting holes on the end wall of the reverse osmosis water tank 24. A disinfection device 25-1 is connected to the disinfection and reused water tank 25. On the side of the disinfection and reused water tank 25 far from the reverse osmosis water tank 24, there is a reused water pump 25-2 connected through a reused water pump suction pipe 25-21. The other side of the reused water pump 25-2 is connected with a reused water pump pressure pipe 25-22.,

[0048] According to a high-concentration organic industrial wastewater treatment near-zero discharge system, a high-concentration organic industrial wastewater treatment near-zero discharge method will also be provided, including the following steps:

[0049] Step 1: The high-concentration organic industrial wastewater enters the regulation tank 1 through the inlet pipe 1-1. After removing slag through the mechanical grille 1-2, the pH is adjusted. Dilute sulfuric acid solution is added to the regulation tank through the acid liquid tank 15-3 arranged in the chemical dosing room 15 and the pH adjustment acid addition pipe 1-3 connected thereto to adjust the pH to 7 - 8. The residence time in the regulation tank is 12 h;

[0050] The treated water with adjusted water quality and quantity flows into the hydrolysis acidification tank 2 through the connecting holes in the end pool wall of the regulating tank 1 for hydrolysis and acidification two-stage facultative microbial reactions. Utilizing the characteristics of acid production and strong adaptability of hydrolysis and acidification bacteria, the macromolecular structures that are difficult to degrade in the treated water are opened and broken into soluble small molecules to improve biodegradability and lay a foundation for the subsequent treatment process. The air stirring pipe 2-1 at the bottom of the tank is opened once every 4 hours, each time for 20 minutes, to provide and maintain a dissolved oxygen of 0.3-0.5 mg / L in the hydrolysis acidification tank 2. The residence time of the hydrolysis acidification tank 2 is 8 hours;

[0051] The effluent from the hydrolysis acidification tank 2 enters the first-stage anoxic tank 3 through the connecting holes in the end pool wall of the hydrolysis acidification tank. The bottom diagonal flow stirring device 3-1 at the bottom of the tank provides 0.5-1 mg / L of dissolved oxygen required for denitrification. The biofilm attached to the elastic three-dimensional denitrification filler 3-2 set in the tank forms a micro A / O unit. The existence of an anoxic microenvironment inside the biofilm helps the denitrification reaction to proceed. The treated wastewater in the first-stage anoxic tank 3 is mixed with the nitrified liquid provided by the nitrified liquid reflux pump 5-1 at the bottom of the sewage reflux well 5 and the first-stage nitrified liquid reflux pipe 3-3 connected thereto, and the first-stage microbial denitrification reaction is completed. NOx--N is converted into N2 and escapes from the wastewater, and nitro-oxidized organic matter is utilized. The nitrified liquid reflux ratio R = 3-4. The excess sludge is refluxed by the sludge reflux pump 6-1 at the bottom of the intermediate sedimentation tank 6 and the sludge reflux pipe 3-4 connected thereto for phosphorus release. The sludge reflux ratio r = 1, and the denitrification load of the first-stage anoxic tank 3 is 0.14 kgNOx--N / kgMLSS·d;

[0052] The effluent from the first-stage anoxic tank 3 enters the first-stage aerobic tank 4 through the connecting holes in the end pool wall of the first-stage anoxic tank 3. The bottom aerator assembly 4-1 and the bottom aerator assembly inlet pipe 4-2 provided at the bottom of the tank provide 2-4 mg / L of dissolved oxygen required for nitrification reaction. The biofilm attached to the polyurethane high-efficiency biological carrier filler 4-3 set in the tank has a large amount of biomass and rich biological phases, which is conducive to the proliferation of nitrifying bacteria that are sensitive to environmental conditions, have slow proliferation, and weak competitiveness. Under aerobic conditions, part of the organic matter in the wastewater is used by the microorganisms in the tank to synthesize new cells, and the other part of the organic matter is decomposed metabolically to obtain the energy required by the cells. The final products are stable substances such as CO2 and H2O. While the organic matter is being oxidized, the organic nitrogen in the wastewater is also oxidized into ammonia nitrogen. Under the conditions of sufficient dissolved oxygen and a long sludge age, ammonia nitrogen is further converted into nitrite and nitrate. The acid radicals generated during nitrification cause the pH to decrease. When the pH ≤ 6.3, Na2CO3 alkaline solution is added by the alkaline solution tank 15-1 in the chemical dosing room 15 and the alkaline solution dosing pipe 4-4 connected thereto to maintain the pH at 7-8. The nitrification load of the first-stage aerobic tank 4 is 0.10 kgNH3-N / kgMLSS·d;

[0053] The effluent of the first aerobic tank 4 enters the sewage return well 5 through the connecting holes on the end wall of the first aerobic tank 4. A part of it is transported by the nitrification liquid return pump 5-1 installed at the bottom of the tank and the connected first-stage nitrification liquid return pipe 3-3 to the first anaerobic tank 3. The nitrification liquid containing nitrite bacteria and nitrate bacteria is mixed with the treated water in the tank for denitrification and nitrogen removal. Another part enters the intermediate sedimentation tank 6. The inclined plate assembly 6-2 in the intermediate sedimentation tank separates the sludge and water from the effluent after the treatment of the first anaerobic tank 3 / first aerobic tank 4 process. The water after sludge and water separation enters the second anaerobic tank 7 through the connecting holes on the end wall of the intermediate sedimentation tank 6. The surplus sludge after sludge and water separation enters the first anaerobic tank 3 through the sludge return pump 6-1 and the connected sludge return pipe 3-4. The surface load of the intermediate sedimentation tank is 1.2 m³ / (㎡·h).

[0054] The above-mentioned first-stage nitrogen and phosphorus removal and organic matter removal are carried out through the first anaerobic tank 3 / first aerobic tank 4 process. After being treated by the first anaerobic tank 3 / first aerobic tank 4, the effluent COD is about 100 mg / L, and TN is 60 mg / L, mainly nitrate nitrogen. Therefore, the second anaerobic tank 7 / second aerobic tank 8 process is required for treatment.

[0055] In the second anaerobic tank 7, the bottom push-flow mixer 7-1 installed diagonally at the bottom of the tank provides 0.5-1 mg / L of dissolved oxygen required for the microbial denitrification reaction. The combined denitrification filler 7-2 installed in the tank can provide a sufficient and stable microbial flora after biological film formation. Moreover, due to the unity and sealing of the biological film, the aerobic, anoxic, and anaerobic synergistic effects are naturally formed due to the different oxygen concentrations received by the surface, middle, and inner layers of the film body, realizing synchronous nitrification-denitrification reaction to improve the nitrogen and phosphorus removal effect. The treated wastewater in the second anaerobic tank 7 is mixed with the reflux nitrification liquid provided by the second-stage nitrification liquid return pump 8-4 installed in the second aerobic tank 8 and the connected second-stage nitrification liquid return pipe 7-3. Since the total nitrogen in the effluent after passing through the first anaerobic tank 3 / first aerobic tank 4 is still about 60 mg / L and mainly nitrate nitrogen; although the effluent COD is about 100 mg / L, its biodegradability is poor. Therefore, an additional carbon source needs to be supplemented to strengthen the denitrification effect. The additional carbon source is a high-quality plant carbon source, and the dosage is 1 g / h·L. The additional carbon source is added by the additional carbon source solution tank 15-2 installed in the chemical dosing room 15, the connected additional carbon source inlet pipe 7-4, and the additional carbon source dosing tank 7-5. Under the condition of sufficient carbon source, the second-stage microbial denitrification reaction is completed, and NOx--N is further converted into N2 and escapes from the wastewater. And the nitro-oxidized organic matter is further utilized. The nitrification liquid reflux ratio R = 2-3. The denitrification load of the second anaerobic tank is 0.12 kgNH3-N / kgMLSS·d.

[0056] The effluent of the secondary anoxic tank 7 enters the secondary aerobic tank 8 through the connecting holes on the end wall of the secondary anoxic tank 7. The dissolved oxygen required for the secondary nitrification reaction, which is 1 - 2 mg / L, is provided by the bottom aeration pipe assembly 8-1 and the bottom aeration pipe inlet pipe 8-2 arranged at the bottom of the tank. Due to the physical interception of the MBR membrane module 8-3 installed in the tank, all microorganisms can be intercepted, enabling the maintenance of activated sludge with a concentration of 6000 - 8000 mg / L in the tank to treat the wastewater. Since the HRT (Hydraulic Retention Time) and SRT (Sludge Retention Time) are completely separated, it is easy to achieve the effect of simultaneous nitrification and denitrification. In the secondary aerobic tank 8, during the nitrification process, organic matter is first oxidized, and then ammonium is oxidized. Nitritation and nitrification proceed in series. The air-water ratio of the secondary aerobic tank 8 is 20:1, and the average membrane flux is 20 L / h·㎡. The nitrification load of the secondary aerobic tank 8 is 0.08 kgNH3--N / kgMLSS·d;

[0057] The above process of denitrification, phosphorus removal, and removal of organic pollutants is carried out through the secondary anoxic tank 7 / secondary aerobic tank 8 process.

[0058] The effluent of the secondary aerobic tank 8 enters the secondary sedimentation tank 9 through the bottom connecting through holes on the end wall of the secondary aerobic tank 8. The inclined tube assembly 9-1 separates the sludge and water from the effluent treated by the secondary anoxic tank 7 / secondary aerobic tank 8 process. The water after sludge and water separation enters the collection well 10 through the connecting holes on the upper part of the end wall of the secondary sedimentation tank. The excess sludge after sludge and water separation enters the sludge thickening tank 11 through the lower part of the end wall of the secondary sedimentation tank. The surface load of the secondary sedimentation tank is 1.0 m³ / (㎡·h). After being treated by the secondary anoxic tank 7 / secondary aerobic tank 8, the effluent has a COD of about 50 mg / L, ammonia nitrogen of about 1 mg / L, total nitrogen of about 15 mg / L, and phosphorus of about 0.5 mg / L, meeting the Class A standard of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants (GB18919-2002).

[0059] The treated water in the transfer collection well 10 enters the multi-media filter 16 through the collection well lift pump 10-1 and the collection well lift pump pressure pipe 10-2 arranged at the bottom of the tank and the multi-media filter inlet pipe 16-1 connected thereto. It is filtered through the composite multi-media filter layer 16-3 to intercept and remove suspended solids and other impurities in the water. The filtration rate of the multi-media filter is 4 - 5 m / h.

[0060] The water output from the multi-media filter 16 enters the ultrafiltration device 17 through the multi-media filter outlet pipe 16-2 at the bottom of the multi-media filter 16 and the ultrafiltration device inlet pipe 17-1 at the bottom of the ultrafiltration device 17 connected thereto, intercepting macromolecular substances with a diameter of 0.01 - 0.1 μm such as suspended solids, particulate matter, biological contamination, colloids, bacteria, etc., to meet the water quality requirements for the reverse osmosis membrane inlet. The ultrafiltration device 17 needs to be backwashed every 1 hour of operation. The backwash water is provided by the ultrafiltration backwash pump 18-2 and the ultrafiltration backwash pump pressure pipe 18-21 arranged at the bottom of the ultrafiltration water tank (18). The static pressure of the ultrafiltration device is 0.1 - 0.5 MPa.

[0061] The water output from the ultrafiltration device 17 enters the ultrafiltration water tank 18 through the ultrafiltration device outlet pipe 17-2 arranged at the upper part, and then is lifted to the security filter 20 by the reverse osmosis lift pump suction pipe 19-1, the reverse osmosis lift pump 19, and the reverse osmosis lift pump pressure pipe 19-2 for filtration by the polypropylene PP melt-blown filter element, intercepting and removing particles between 0.03 - 100 μm to protect the reverse osmosis membrane of the subsequent process.

[0062] The water output from the security filter 20 enters the reverse osmosis device 22 through the security filter outlet pipe 20-2 arranged at the lower part, the reverse osmosis high-pressure pump suction pipe 21-1, the reverse osmosis high-pressure pump 21, the reverse osmosis high-pressure pump pressure pipe 21-2, and the reverse osmosis device inlet pipe 22-1 at the upper part of the head end of the reverse osmosis device 22. The intercepted components are small molecule solutes, organic impurities, and dissolved inorganic salts with a size of 1 - 10 Å. When the membrane flux drops by 10% - 15% and the conductivity of the permeate water increases by 5% - 10%, the reverse osmosis membrane needs to be cleaned. The cleaning agent is MCT410, which is added through the cleaning agent dosing tank 22-4. The scale inhibitor is EWT620, which is added through the scale inhibitor dosing tank 22-5. The water treated by the reverse osmosis device 22 enters the reverse osmosis water tank 24 through the reverse osmosis device product water pipe 22-2 arranged at the end of the reverse osmosis device 22. The reverse osmosis device uses an aromatic polyamide membrane, with a designed flux of 20.0 L / (㎡·h) and an operating pressure of 1.55 MPa.

[0063] The water output from the reverse osmosis water tank 24 enters the disinfection and reuse water tank 25 through the connecting hole in the end wall of the reverse osmosis water tank 24, and is disinfected by the disinfection equipment 25-1. After the water quality meets the industrial water reuse or industrial cooling circulating water quality standard, it is connected to the internal industrial water pipe network of the factory through the reuse water pump suction pipe 25-21, the reuse water pump 25-2, and the reuse water pump pressure pipe 25-22;

[0064] Step 2: The excess sludge separated from sludge and water in the secondary sedimentation tank 9 enters the sludge thickening tank 11 through the bottom connecting holes at the end of the secondary sedimentation tank 9, and the residence time in the sludge thickening tank is 16 h. The thickened sludge is transported to the plate and frame filter press 12-2 in the plate and frame filter press room 12 through the screw pump sludge suction pipe 11-1 and the screw pump 12-1 arranged in the plate and frame filter press room 12 for filtering to a sludge with a moisture content of 70-75%. The filtered sludge is sent by a conveyor belt to the mixing and stirring machine 13-1 arranged in the functional organic fertilizer manufacturing room 13, and a heavy metal composite stabilizer and a sludge conditioner are added. The heavy metal composite stabilizer is composed of 50% fly ash, 16.7% ferric chloride, 16.7% polyaluminum sulfate, and 16.6% formamidine. The dosage is 0.02 kg / m³ of sludge. The sludge conditioner is composed of organic carbon bacteria liquid and enzyme. The dosages are 3 kg / m³ and 0.01 kg / m³ of sludge respectively. After mixing and stirring for 5 minutes, it is transported to the small and rapid composting machine 13-2 and made into a functional organic fertilizer (soilless cultivation substrate) with a particle size of 1.0-2.0 mm through processes such as fermentation, and finally packaged by the screening and packaging machine 13-3. The soilless cultivation substrate can be used for soilless cultivation of vegetables, flowers, family balconies, and industrialized plant soilless cultivation;

[0065] Step 3: The method is that the concentrated water generated by the reverse osmosis process for the advanced treatment of water is evaporated by MVR, and the evaporation concentrate is used for the dehumidification and slag removal section;

[0066] The concentrated water generated during the water treatment process by the reverse osmosis device 22 enters the MVR evaporator 23 through the reverse osmosis device concentrated water pipe 22-3 and the MVR evaporator feed pipe 23-1 connected thereto for evaporation and crystallization treatment. The condensed water generated during the evaporation and crystallization process enters the multi-media filter 16 through the condensate pipe 23-3 and the multi-media filter water inlet pipe 16-1 connected thereto, and the evaporation crystallization concentrate is discharged through the concentrate discharge pipe 23-2 for the dehumidification and slag removal section. Example

[0067] The reclaimed water for the advanced treatment of high-concentration organic industrial wastewater is used for industrial reuse

[0068] Taking a high-concentration petrochemical organic industrial wastewater treatment project supporting a large petrochemical enterprise as an example, it is described in detail in combination with Example 1.

[0069] The wastewater discharged from each production device of this petrochemical enterprise is divided into two categories: ① The wastewater discharged from petrochemical devices, including cyclohexane, cyclohexene, cyclohexanone prepared by non-catalytic oxidation, nylon, polyester, synthetic rubber, epoxy resin, etc.; ② The refinery wastewater discharged from the olefin plant.

[0070] The designed water treatment capacity of this project is 500 - 600 m³ / h, with pH 8 - 9, COD 900 - 2000 mg / L, ammonia nitrogen 120 - 380 mg / L, total phosphorus 11 - 16 mg / L, and total nitrogen 200 - 400 mg / L.

[0071] This project uses the system of Example 1 for treatment.

[0072] The high-concentration organic industrial wastewater enters the regulating tank 1 through the inlet pipe 1 - 1. After removing slag by the mechanical grille 1 - 2, the pH is adjusted. Dilute sulfuric acid solution is added to the regulating tank through the acid liquid tank 15 - 3 in the chemical dosing room 15 and the connected pH-adjusting acid adding pipe 1 - 3 to adjust the pH to 7 - 8. The residence time in the regulating tank is 12 h.

[0073] The treated water with adjusted water quality and quantity flows into the hydrolysis acidification tank 2 through the connecting hole in the end wall of the regulating tank 1 for hydrolysis and acidification reactions of facultative microorganisms in two stages. Utilizing the characteristics of hydrolysis and acidification bacteria with strong acid production ability and adaptability, the macromolecular structures that are difficult to degrade in the treated water are opened and broken into soluble small molecules to improve biodegradability, laying a good foundation for the subsequent treatment process. The air stirring pipe 2 - 1 at the bottom of the tank is opened once every 4 h, each time for 20 min, to provide and maintain a dissolved oxygen of 0.3 - 0.5 mg / L in the hydrolysis acidification tank 2. The residence time in the hydrolysis acidification tank 2 is 8 h.

[0074] The effluent from the hydrolysis acidification tank 2 enters the first-stage anoxic tank 3 through the connecting hole in the end wall of the hydrolysis acidification tank. The bottom diagonal flow-through agitator 3 - 1 in the tank provides the 0.5 - 1 mg / L dissolved oxygen required for the denitrification reaction. The biofilm attached to the elastic three-dimensional denitrification filler 3 - 2 set in the tank forms a micro A / O unit. The existence of an anoxic microenvironment inside the biofilm helps the denitrification reaction to proceed. The treated wastewater in the first-stage anoxic tank 3 is mixed with the nitrified liquid provided by the nitrified liquid reflux pump 5 - 1 at the bottom of the sewage reflux well 5 and the connected first-stage nitrified liquid reflux pipe 3 - 3 to complete the first-stage microbial denitrification reaction, converting NOx--N into N2 and escaping from the wastewater, and using nitro-oxidized organic matter. The nitrified liquid reflux ratio R = 3 - 4. The excess sludge is refluxed by the sludge reflux pump 6 - 1 at the bottom of the intermediate sedimentation tank 6 and the connected sludge reflux pipe 3 - 4 for phosphorus release. The sludge reflux ratio r = 1. The denitrification load of the first-stage anoxic tank 3 is 0.14 kgNH3-N / kgMLSS·d.

[0075] The effluent of the first-stage anoxic tank 3 enters the first-stage aerobic tank (O1) 4 through the connecting holes in the end wall of the first-stage anoxic tank 3. The dissolved oxygen required for nitrification reaction, which is 2-4 mg / L, is provided by the bottom aerator assembly 4-1 and the intake pipe 4-2 of the bottom aerator assembly installed at the bottom of the tank. The biomass of the biofilm attached to the high-efficiency polyurethane biological carrier filler 4-3 installed in the tank is large and the biological phase is rich, which is conducive to the proliferation of nitrifying bacteria that are sensitive to environmental conditions, have slow proliferation rate and weak competitiveness. Under aerobic conditions, part of the organic matter in the wastewater is used by the microorganisms in the tank to synthesize new cells, and the other part of the organic matter is decomposed metabolically to obtain the energy required by the cells. The final products are stable substances such as CO2 and H2O. While the organic matter is being oxidized, the organic nitrogen in the wastewater is also oxidized into ammonia nitrogen. Under the conditions of sufficient dissolved oxygen and long sludge age, the ammonia nitrogen is further converted into nitrite and nitrate. The acid radicals generated during the nitrification process cause the pH to decrease. When pH ≤ 6.3, Na2CO3 alkaline solution is added to the tank from the alkaline solution tank 15-1 installed in the chemical dosing room 15 and the connected alkaline solution dosing pipe 4-4 to maintain the pH at 7-8. The nitrification load of the first-stage aerobic tank (O1) 4 is 0.10 kgNH3--N / kgMLSS·d.

[0076] The effluent of the first-stage aerobic tank (O1) 4 enters the sewage return well 5 through the connecting holes in the end wall of the first-stage aerobic tank (O1) 4. Part of it is transported by the nitrification liquid return pump 5-1 installed at the bottom of the tank and the connected first-stage nitrification liquid return pipe 3-3 to the first-stage anoxic tank 3 to mix the nitrification liquid containing nitrite bacteria and nitrate bacteria with the treated water in the tank for denitrification and nitrogen removal. The other part enters the intermediate sedimentation tank 6, and the inclined plate assembly 6-2 separates the sludge and water from the effluent treated by the first-stage anoxic tank / first-stage aerobic tank (O1) process. The water after sludge and water separation enters the second-stage anoxic tank 7 through the connecting holes in the end wall of the intermediate sedimentation tank 6. The excess sludge after sludge and water separation enters the first-stage anoxic tank 3 through the sludge return pump 6-1 and the connected sludge return pipe 3-4. The surface load of the intermediate sedimentation tank is 1.2 m³ / (㎡·h).

[0077] The above-mentioned first-stage denitrification, phosphorus removal and removal of organic pollutants are carried out through the first-stage anoxic tank / first-stage aerobic tank (O1) process. After being treated by the first-stage anoxic tank / first-stage aerobic tank (O1), the effluent has a COD of about 100 mg / L and a TN of 60 mg / L, mainly nitrate nitrogen. Therefore, the second-stage anoxic tank / second-stage aerobic tank (O2) process is required for treatment.

[0078] The secondary anoxic tank 7 is provided with 0.5 - 1 mg / L of dissolved oxygen required for the microbial denitrification reaction by the bottom - flow agitator 7 - 1 arranged diagonally at the bottom of the tank. The combined denitrification packing 7 - 2 arranged in the tank can provide a sufficient and stable microbial flora after biological film formation. Moreover, due to the cohesiveness and sealing of the biological film, the oxygen concentrations received by the surface, middle, and inner layers of the film body are different, thus naturally forming the synergistic effects of aerobic, anoxic, and anaerobic conditions, realizing the simultaneous nitrification - denitrification reaction to improve the denitrification treatment effect. The treated wastewater in the secondary anoxic tank 7 is mixed with the returned nitrified liquid provided by the secondary nitrified liquid reflux pump 8 - 4 arranged in the secondary aerobic tank (O2) 8 and the connected secondary nitrified liquid return pipe 7 - 3. Since the total nitrogen in the effluent from the primary anoxic / secondary aerobic tank (O1) is still about 60 mg / L and mainly in the form of nitrate nitrogen; although the COD in the effluent is about 100 mg / L, its biodegradability is poor. Therefore, an external carbon source needs to be added to enhance the denitrification effect. The external carbon source is a high - quality plant carbon source, and the dosage is 1 g / h·L. The external carbon source is added by the external carbon source solution tank 15 - 2 arranged in the chemical dosing room 15, the connected external carbon source inlet pipe 7 - 4, and the external carbon source dosing tank 7 - 5. Under the condition of sufficient carbon source, the secondary microbial denitrification reaction is completed, further converting NHx - - N into N2 and escaping from the wastewater. And the nitro - oxidized organic matter is further utilized. The nitrified liquid reflux ratio R = 2 - 3. The denitrification load of the secondary anoxic tank 7 is 0.12 kgNH3 - N / kgMLSS·d.

[0079] The effluent from the secondary anoxic tank 7 enters the secondary aerobic tank (O2) 8 through the connecting holes on the end - wall of the secondary anoxic tank 7. The bottom - aeration pipe assembly 8 - 1 arranged at the bottom of the tank and the bottom - aeration pipe inlet pipe 8 - 2 provide 1 - 2 mg / L of dissolved oxygen required for the secondary nitrification reaction. Due to the physical interception of the MBR membrane module 8 - 3 arranged in the tank, all microorganisms can be intercepted, so that the activated sludge with a concentration of 6000 - 8000 mg / L can be maintained in the tank to treat the wastewater. Since the HRT (hydraulic retention time) and SRT (sludge retention time) are completely separated, it is easy to obtain the effect of simultaneous nitrification - denitrification. In the secondary aerobic tank (O2) 8, during the nitrification process, organic matter is first oxidized, and then ammonium is oxidized. Nitritation and nitrification are carried out in series. The air - water ratio of the secondary aerobic tank (O2) 8 is 20:1, and the average membrane flux is 20 L / h·㎡. The nitrification load of the secondary aerobic tank (O2) 8 is 0.08 kgNH3 - - N / kgMLSS·d.

[0080] The above - mentioned secondary denitrification, dephosphorization, and removal of organic pollutants are carried out through the secondary anoxic tank / secondary aerobic tank (O2) process.

[0081] The effluent from the secondary aerobic tank (O2) 8 enters the secondary sedimentation tank 9 through the connecting holes at the bottom of the end wall of the secondary aerobic tank (O2) 8. The inclined tube assembly 9-1 separates the sludge and water from the effluent after the treatment of the secondary anoxic tank / secondary aerobic tank (O2) process. The water after sludge and water separation enters the collecting well 10 through the connecting holes at the upper part of the end wall of the secondary sedimentation tank. The excess sludge after sludge and water separation enters the sludge thickening tank 11 through the lower part of the end wall of the secondary sedimentation tank. The surface loading of the secondary sedimentation tank is 1.0 m³ / (㎡·h). After being treated by the secondary anoxic tank / secondary aerobic tank (O2), the effluent has a COD of about 50 mg / L, ammonia nitrogen of about 1 mg / L, total nitrogen of about 15 mg / L, and phosphorus of about 0.5 mg / L, meeting the Class-A standard of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants (GB18919-2002).

[0082] The treated water in the transfer collecting well 10 enters the multimedia filter 16 through the collecting well lift pump 10-1 installed at the bottom of the tank, the collecting well lift pump pressure pipe 10-2, and the inlet pipe of the multimedia filter 16-1 connected thereto. It is filtered through the composite multimedia filter layer 16-3 to intercept and remove suspended solids and other impurities in the water. The filtration rate of the multimedia filter is 4-5 m / h.

[0083] The effluent of the multimedia filter 16 enters the ultrafiltration device 17 through the multimedia filter outlet pipe 16-2 at the bottom of the multimedia filter 16 and the ultrafiltration device inlet pipe 17-1 at the bottom of the ultrafiltration device 17 connected thereto, intercepting macromolecular substances with a diameter of 0.01-0.1 μm, such as suspended matter, particulate matter, biological contaminants, colloids, bacteria, etc., to meet the water quality requirements for the inlet of the reverse osmosis membrane. After the ultrafiltration device 17 works for 1 h, backwashing is required, and the backwashing water is provided by the ultrafiltration backwash pump 18-2 installed at the bottom of the ultrafiltration water tank 18 and the ultrafiltration backwash pump pressure pipe 18-21. The static pressure of the ultrafiltration device is 0.1-0.5 MPa.

[0084] The effluent of the ultrafiltration device 17 enters the ultrafiltration water tank 18 through the ultrafiltration device outlet pipe 17-2 installed at the upper part, and then is lifted to the security filter 20 through the reverse osmosis lift pump suction pipe 19-1, the reverse osmosis lift pump 19, and the reverse osmosis lift pump pressure pipe 19-2 for filtration by the polypropylene PP melt-blown filter element to intercept and remove particles between 0.03-1000 μm to protect the reverse osmosis membrane of the subsequent process.

[0085] The water outlet of the security filter 20 enters the reverse osmosis device 22 through the security filter outlet pipe 20-2 arranged at the lower part, the reverse osmosis high-pressure pump suction pipe 21-1 connected thereto, the reverse osmosis high-pressure pump 21, the reverse osmosis high-pressure pump pressure pipe 21-2, and the reverse osmosis device inlet pipe 22-1 at the upper part of the head end of the reverse osmosis device 22, intercepting small molecule solutes, organic impurities, and dissolved inorganic salts with a retention component of 1-10 Å. When the membrane flux drops by 10%-15% and the conductivity of the permeated water increases by 5%-10%, the reverse osmosis membrane needs to be cleaned. The cleaning agent is MCT410, which is added through the cleaning agent dosing tank 22-4. The scale inhibitor is EWT620, which is added through the scale inhibitor dosing tank 22-5. The water treated by the reverse osmosis device 22 enters the reverse osmosis water tank 24 through the reverse osmosis device product water pipe 22-2 arranged at the end of the reverse osmosis device 22. The reverse osmosis device uses an aromatic hydrocarbon polyurethane membrane, with a designed flux of 20.0 L / (㎡·h) and an operating pressure of 1.55 MPa.

[0086] The water outlet of the reverse osmosis water tank 24 enters the disinfection and reused water tank 25 through the connecting hole in the end wall of the reverse osmosis water tank 24, and is disinfected by the disinfection equipment 25-1. After the water quality reaches the industrial water reuse or industrial cooling circulating water quality standard, it is connected to the internal industrial water pipe network of the factory through the reused water pump suction pipe 25-21, the reused water pump 25-2, and the reused water pump pressure pipe 25-22. Example

[0087] For Example 2, the concentrated sludge generated during the wastewater treatment process is used to manufacture organic fertilizer (soilless cultivation substrate) after pressure filtration and improvement.

[0088] The excess sludge after sludge and water separation in the secondary sedimentation tank 9 enters the sludge thickening tank 11 through the connecting hole at the bottom of the end of the secondary sedimentation tank 9. The residence time of the sludge thickening tank is 16 h. The thickened sludge is transported to the plate and frame filter press 12-2 through the screw pump suction pipe 11-1 and the screw pump 12-1 arranged in the plate and frame filter press room 12 for pressure filtration to obtain sludge with a moisture content of 70-75%. The pressure-filtered sludge is sent into the mixing and stirring machine 13-1 arranged in the functional organic fertilizer manufacturing room 13 by a conveyor belt, and a heavy metal composite stabilizer and a sludge improver are added. The heavy metal composite stabilizer consists of 50% fly ash, 16.7% ferric chloride, 16.7% polyaluminum sulfate, and 16.6% sodium dimethyldithiocarbamate. The dosage is 0.02 kg / m³. The sludge improver consists of organic carbon bacteria liquid and enzyme. The dosages are 3 kg / m³ of sludge and 0.01 kg / m³ of sludge respectively. After mixing and stirring for 5 minutes, it is transported to a small-scale rapid composting machine 13-2 and made into a functional organic fertilizer (soilless cultivation substrate) with a particle size of 1.0-2.0 mm through processes such as fermentation, and finally packaged by a screening and packaging machine 13-3. The soilless cultivation substrate can be used for soilless cultivation of vegetables, flowers, on family balconies, and in industrialized plant soilless cultivation. Example

[0089] For Example 2, the concentrated water generated in the reverse osmosis process of deep water treatment is evaporated by MVR, and the evaporation concentrate is used for blending in the dehumidification and slag removal section.

[0090] The concentrated water generated during the water treatment process by the reverse osmosis device 22 enters the evaporator 23 through the reverse osmosis device concentrated water pipe 22-3 and the MVR evaporator feed pipe 23-1 connected thereto for evaporation crystallization treatment. The condensed water generated during the evaporation crystallization process enters the multi-media filter 16 through the condensate pipe 23-3 and the multi-media filter water inlet pipe 16-1 connected thereto. The evaporation crystallization concentrate is discharged through the concentrate discharge pipe 23-2 for blending in the dehumidification and slag removal section.

[0091] The specific process of the present invention is as follows:

[0092] Step 1:

[0093] The high-concentration organic industrial wastewater enters the regulating tank 1 through the water inlet pipe 1-1. After slag removal by the mechanical grille 1-2, the pH is adjusted. Dilute sulfuric acid solution is added to the regulating tank through the acid liquid tank 15-3 arranged in the chemical dosing room 15 and the pH adjustment acid adding pipe 1-3 connected thereto to adjust the pH to 7-8. The residence time of the regulating tank is 12 h;

[0094] The treated water with adjusted water quality and quantity flows into the hydrolysis acidification tank 2 through the connecting hole in the end wall of the regulating tank 1 for hydrolysis and acidification two-stage facultative microbial reactions. Utilizing the characteristics of acid production and strong adaptability of hydrolysis and acidification bacteria, the macromolecular structures that are difficult to degrade in the treated water are opened and broken into soluble small molecules to improve the biodegradability and lay a foundation for the subsequent treatment process. The air stirring pipe 2-1 at the bottom of the tank is opened once every 4 h, each time for 20 min, to provide and maintain a dissolved oxygen of 0.3-0.5 mg / L in the hydrolysis acidification tank 2. The residence time of the hydrolysis acidification tank 2 is 8 h;

[0095] The effluent from the hydrolysis acidification tank 2 enters the first-stage anoxic tank 3 through the connecting holes in the end wall of the hydrolysis acidification tank. The bottom flow pusher agitator 3-1 arranged diagonally at the bottom of the tank provides 0.5-1 mg / L of dissolved oxygen required for denitrification. The biofilm attached to the elastic three-dimensional denitrification filler 3-2 arranged in the tank forms a micro A / O unit. The existence of an anoxic microenvironment inside the biofilm helps the denitrification reaction to proceed. The treated wastewater in the first-stage anoxic tank 3 is mixed with the nitrified liquid provided by the nitrified liquid reflux pump 5-1 arranged at the bottom of the sewage reflux well 5 and the first-stage nitrified liquid reflux pipe 3-3 connected thereto, and the first-stage microbial denitrification reaction is completed. NOx--N is converted into N2 and escapes from the wastewater, and nitro-oxidized organic matter is utilized. The nitrified liquid reflux ratio R = 3-4. The excess sludge is refluxed by the sludge reflux pump 6-1 arranged at the bottom of the intermediate sedimentation tank 6 and the sludge reflux pipe 3-4 connected thereto for phosphorus release. The sludge reflux ratio r = 1, and the denitrification load of the first-stage anoxic tank 3 is 0.14 kgNOx--N / kgMLSS·d;

[0096] The effluent from the first-stage anoxic tank 3 enters the first-stage aerobic tank 4 through the connecting holes in the end wall of the first-stage anoxic tank 3. The bottom aerator assembly 4-1 arranged at the bottom of the tank and the bottom aerator assembly inlet pipe 4-2 provide 2-4 mg / L of dissolved oxygen required for nitrification reaction. The biofilm attached to the polyurethane high-efficiency biological carrier filler 4-3 arranged in the tank has a large biomass and a rich biological phase, which is beneficial to the proliferation of nitrifying bacteria that are sensitive to environmental conditions, have a slow proliferation rate, and weak competitiveness. Under aerobic conditions, the microorganisms in the tank use part of the organic matter in the wastewater to synthesize new cells, and decompose and metabolize another part of the organic matter to obtain the energy required by the cells. The final products are stable substances such as CO2 and H2O. While the organic matter is being oxidized, the organic nitrogen in the wastewater is also oxidized into ammonia nitrogen. Under the conditions of sufficient dissolved oxygen and a long sludge age, ammonia nitrogen is further converted into nitrite and nitrate. The acid radicals generated during the nitrification process cause the pH to decrease. When pH ≤ 6.3, Na2CO3 alkaline solution is added by the alkaline solution tank 15-1 arranged in the chemical dosing room 15 and the alkaline solution dosing pipe 4-4 connected thereto to maintain the pH at 7-8. The nitrification load of the first-stage aerobic tank 4 is 0.10 kgNH3-N / kgMLSS·d;

[0097] The effluent from the first aerobic tank 4 enters the sewage return well 5 through the connecting holes on the end wall of the first aerobic tank 4. Part of it is transported by the nitrification liquid return pump 5-1 installed at the bottom of the tank and the connected first-stage nitrification liquid return pipe 3-3 to the first anoxic tank 3, where the nitrification liquid containing nitrite bacteria and nitrate bacteria is mixed with the treated water in the tank for denitrification and nitrogen removal. Another part enters the intermediate sedimentation tank 6, and the inclined plate assembly 6-2 in the intermediate sedimentation tank 6 separates the sludge and water from the effluent after the treatment of the first anoxic tank 3 / first aerobic tank 4 process. The water after sludge and water separation enters the second anoxic tank 7 through the connecting holes on the end wall of the intermediate sedimentation tank 6. The excess sludge after sludge and water separation enters the first anoxic tank 3 through the sludge return pump 6-1 and the connected sludge return pipe 3-4. The surface load of the intermediate sedimentation tank is 1.2 m³ / (㎡·h).

[0098] The above-mentioned first-stage denitrification, phosphorus removal and organic matter removal are carried out through the first anoxic tank 3 / first aerobic tank 4 process. After being treated by the first anoxic tank 3 / first aerobic tank 4, the effluent COD is about 100 mg / L, and TN is 60 mg / L, mainly nitrate nitrogen. Therefore, the second anoxic tank 7 / second aerobic tank 8 process is required for treatment.

[0099] In the second anoxic tank 7, the bottom push-flow mixer 7-1 installed diagonally at the bottom of the tank provides 0.5-1 mg / L of dissolved oxygen required for the microbial denitrification reaction. The combined denitrification filler 7-2 installed in the tank can provide a sufficient and stable microbial flora after biological film formation. Moreover, due to the unity and sealing of the biological film, the aerobic, anoxic and anaerobic synergistic effects are naturally formed due to the different oxygen concentrations received by the surface, middle and inner layers of the film body, realizing synchronous nitrification-denitrification reaction to improve the denitrification and phosphorus removal effects. The treated wastewater in the second anoxic tank 7 is mixed with the reflux nitrification liquid provided by the second-stage nitrification liquid return pump 8-4 installed in the second aerobic tank 8 and the connected second-stage nitrification liquid return pipe 7-3. Since the total nitrogen in the effluent from the first anoxic tank 3 / first aerobic tank 4 is still about 60 mg / L and mainly nitrate nitrogen; although the COD effluent is about 100 mg / L, its biodegradability is poor. Therefore, an additional carbon source needs to be added to strengthen the denitrification effect. The additional carbon source is a high-quality plant carbon source, and the dosage is 1 g / h·L. The additional carbon source is added by the additional carbon source solution tank 15-2 installed in the chemical dosing room 15, the connected additional carbon source inlet pipe 7-4 and the additional carbon source dosing tank 7-5. Under the condition of sufficient carbon source, the second-stage microbial denitrification reaction is completed, and NOx--N is further converted into N2 and escapes from the wastewater. And the nitro-oxidized organic matter is further utilized. The nitrification liquid reflux ratio R = 2-3. The denitrification load of the second anoxic tank is 0.12 kgNH3-N / kgMLSS·d.

[0100] The effluent of the secondary anoxic tank 7 enters the secondary aerobic tank 8 through the connecting holes on the end wall of the secondary anoxic tank 7. The dissolved oxygen required for the secondary nitrification reaction, which is 1 - 2 mg / L, is provided by the bottom aeration pipe assembly 8-1 and the bottom aeration pipe inlet pipe 8-2 arranged at the bottom of the tank. Due to the physical retention effect of the MBR membrane module 8-3 installed in the tank, all microorganisms can be retained, enabling the maintenance of activated sludge with a concentration of 6000 - 8000 mg / L in the tank to treat the wastewater. Since the HRT (Hydraulic Retention Time) and SRT (Sludge Retention Time) are completely separated, it is easy to achieve the effect of simultaneous nitrification and denitrification. In the nitrification process of the secondary aerobic tank 8, organic matter is first oxidized, and then ammonium is oxidized. Nitrosation and nitrification proceed in series. The air-water ratio of the secondary aerobic tank 8 is 20:1, and the average membrane flux is 20 L / h·㎡. The nitrification load of the secondary aerobic tank 8 is 0.08 kgNH3--N / kgMLSS·d;

[0101] The above process of nitrogen and phosphorus removal and organic pollutant removal is carried out through the secondary anoxic tank 7 / secondary aerobic tank 8 process.

[0102] The effluent of the secondary aerobic tank 8 enters the secondary sedimentation tank 9 through the bottom connecting through holes on the end wall of the secondary aerobic tank 8. The inclined tube assembly 9-1 separates the sludge and water from the effluent treated by the secondary anoxic tank 7 / secondary aerobic tank 8 process. The water after sludge and water separation enters the collecting well 10 through the connecting holes on the upper part of the end wall of the secondary sedimentation tank. The excess sludge after sludge and water separation enters the sludge thickening tank 11 through the lower part of the end wall of the secondary sedimentation tank. The surface load of the secondary sedimentation tank is 1.0 m³ / (㎡·h). After treatment by the secondary anoxic tank 7 / secondary aerobic tank 8, the effluent COD is about 50 mg / L, ammonia nitrogen is about 1 mg / L, total nitrogen is about 15 mg / L, and phosphorus is about 0.5 mg / L. It meets the first-class A standard of the Main Pollutant Discharge Standard for Municipal Wastewater Treatment Plants (GB18919 - 2002).

[0103] The treated water in the transfer collecting well 10 enters the multi-media filter 16 through the collecting well lift pump 10-1 and the collecting well lift pump pressure pipe 10-2 arranged at the bottom of the tank and the multi-media filter inlet pipe 16-1 connected thereto. It is filtered through the composite multi-media filter layer 16-3 to intercept and remove suspended solids and other impurities in the water. The filtration rate of the multi-media filter is 4 - 5 m / h.

[0104] The effluent of the multi-media filter 16 enters the ultrafiltration device 17 through the multi-media filter effluent pipe 16-2 at the bottom of the multi-media filter 16 and the ultrafiltration device inlet pipe 17-1 at the bottom of the ultrafiltration device 17 connected thereto, intercepting macromolecular substances with a diameter of 0.01-0.1 μm such as suspended solids, particulate matter, biological contamination, colloids, bacteria, etc., to meet the water quality requirements for the reverse osmosis membrane inlet. The ultrafiltration device 17 needs to be backwashed every 1 hour of operation. The backwash water is provided by the ultrafiltration backwash pump 18-2 and the ultrafiltration backwash pump pressure pipe 18-21 provided at the bottom of the ultrafiltration water tank (18). The static pressure of the ultrafiltration device is 0.1-0.5 MPa.

[0105] The effluent of the ultrafiltration device 17 enters the ultrafiltration water tank 18 through the ultrafiltration device effluent pipe 17-2 provided at the upper part, and then is lifted to the security filter 20 by the reverse osmosis lift pump suction pipe 19-1, the reverse osmosis lift pump 19, and the reverse osmosis lift pump pressure pipe 19-2 for filtration by a polypropylene PP melt-blown filter element, intercepting and removing particles between 0.03-100 μm to protect the subsequent process reverse osmosis membrane.

[0106] The effluent of the security filter 20 enters the reverse osmosis device 22 through the security filter effluent pipe 20-2 provided at the lower part, the reverse osmosis high-pressure pump suction pipe 21-1, the reverse osmosis high-pressure pump 21, the reverse osmosis high-pressure pump pressure pipe 21-2, and the reverse osmosis device inlet pipe 22-1 at the upper part of the head end of the reverse osmosis device 22. The intercepted components are small molecule solutes, organic impurities, and dissolved inorganic salts with a size of 1-10 Å. When the membrane flux drops by 10%-15% and the conductivity of the permeate water increases by 5%-10%, the reverse osmosis membrane needs to be cleaned. The cleaning agent is MCT410, which is added through the cleaning agent dosing tank 22-4. The scale inhibitor is EWT620, which is added through the scale inhibitor dosing tank 22-5. The water treated by the reverse osmosis device 22 enters the reverse osmosis water tank 24 through the reverse osmosis device product water pipe 22-2 provided at the end of the reverse osmosis device 22. The reverse osmosis device uses an aromatic polyamide membrane, with a designed flux of 20.0 L / (㎡·h) and an operating pressure of 1.55 MPa.

[0107] The effluent of the reverse osmosis water tank 24 enters the disinfection and recycled water tank 25 through the connecting hole in the end wall of the reverse osmosis water tank 24, and is disinfected by the disinfection equipment 25-1. After the effluent meets the industrial water reuse or industrial cooling circulating water quality standard, it is connected to the internal industrial water pipe network of the factory through the recycled water pump suction pipe 25-21, the recycled water pump 25-2, and the recycled water pump pressure pipe 25-22;

[0108] Step Two

[0109] After the sludge and water separation in the secondary sedimentation tank 9, the residual sludge enters the sludge thickening tank 11 through the bottom connecting hole at the end of the secondary sedimentation tank 9. The residence time of the sludge thickening tank is 16 hours. The concentrated sludge is conveyed to the plate and frame filter press 12-2 through the screw pump sludge suction pipe 11-1 and the screw pump 12-1 set in the plate and frame filter press room 12 to filter the sludge with a water content of 70-75%. The sludge after filtration is conveyed by the conveyor belt to the mixing mixer 13-1 set in the functional organic fertilizer manufacturing room 13 and heavy metal composite stabilizer and sludge improver are added. The heavy metal composite stabilizer is composed of 50% fly ash, 16.7% ferric chloride, 16.7% polyaluminum sulfate, and 16.6% Formana. The dosage is 0.02kg / m³ sludge. The sludge improver is composed of organic carbon bacteria liquid and enzyme. The dosages are 3kg / m³ and 0.01kg / m³ sludge respectively. After 5 minutes of mixing and stirring, the mixture is transported to a small-scale rapid fertilizer machine 13-2 and fermented to produce a functional organic fertilizer (soilless cultivation matrix) with a particle size of 1.0-2.0 mm, and finally packaged by a screening and packaging machine 13-3. The soilless cultivation matrix can be used for soilless cultivation of vegetables, flowers, family balconies and factory plants;

[0110] Step 3:

[0111] The method is to use MVR to evaporate the concentrated water produced by the reverse osmosis process in the deep water treatment process, and then use the evaporated concentrate in the dehumidification and slag removal section;

[0112] The concentrated water produced by the reverse osmosis device 22 in the water treatment process enters the MVR evaporator 23 through the reverse osmosis device concentrated water pipe 22-3 and the MVR evaporator liquid inlet pipe 23-1 connected thereto for evaporation and crystallization treatment. The condensed water produced in the evaporation and crystallization process enters the multi-media filter 16 through the condensed water pipe 23-3 and the multi-media filter inlet pipe 16-1 connected thereto. The evaporated crystallized concentrate is discharged from the concentrate discharge pipe 23-2 for use in the dehumidification and slag removal section.

[0113] The above is an exemplary description of the present invention in combination with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as such non-substantial improvements are made by adopting the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A high-concentration organic industrial wastewater treatment system with near-zero discharge, characterized in that , including an equalization tank (1), a hydrolysis acidification tank (2), a first-stage anoxic tank (3), a first-stage aerobic tank (4), a sewage return well (5), a middle sedimentation tank (6), a second-stage anoxic tank (7), a second-stage aerobic tank (8), a secondary sedimentation tank (9), a collecting well (10), a sludge thickening tank (11), a plate and frame filter press room (12), a functional organic fertilizer manufacturing room (13), a blower room (14), a chemical dosing room (15), a multi-media filter (16), an ultrafiltration device (17), an ultrafiltration water tank (18), a reverse osmosis lift pump (19), a security filter (20), a reverse osmosis high-pressure pump (21), a reverse osmosis device (22), an MVR evaporator (23), a reverse osmosis water tank (24), and a disinfection and reclaimed water tank (25), wherein the middle sedimentation tank (6) is located inside the sewage return well (5); One side of the equalization tank (1) is connected to a water inlet pipe (1-1) for connecting with high-concentration organic industrial wastewater. A mechanical grille (1-2) is arranged inside the equalization tank (1), and the mechanical grille (1-2) is parallel to the equalization tank (1). The equalization tank (1) is connected to an acid liquid tank (15-3) inside the chemical dosing room (15) through a pH adjustment acid adding pipe (1-3). The equalization tank (1) is connected to the hydrolysis acidification tank (2) through a communication hole in the end wall of the equalization tank (1). A bottom air stirring pipe (2-1) is arranged at the bottom of the hydrolysis acidification tank (2); The hydrolysis acidification tank (2) is connected to the first-stage anoxic tank (3) through a communication hole in the end wall of the hydrolysis acidification tank (2). The first-stage anoxic tank (3) is arranged in a rectangular structure. Two of the four corners of the first-stage anoxic tank (3) are provided with bottom pushing and stirring devices (3-1). Elastic three-dimensional denitrification fillers (3-2) are arranged inside the first-stage anoxic tank (3). A first-stage nitrification liquid return pipe (3-3) is arranged inside one end of the first-stage anoxic tank (3). A nitrification liquid return pump (5-1) is arranged at the bottom of the sewage return well (5). The first-stage nitrification liquid return pipe (3-3) is connected to the nitrification liquid return pump (5-1). A sludge return pipe (3-4) is arranged inside the other end of the first-stage anoxic tank (3). A sludge return pump (6-1) is arranged at the bottom inside the middle sedimentation tank (6). The sludge return pipe (3-4) is connected to the sludge return pump (6-1); The first-stage anoxic tank (3) is connected to the first-stage aerobic tank (4) through a communication hole in the end wall of the first-stage anoxic tank (3). A bottom aerator assembly (4-1), a bottom aerator assembly inlet pipe (4-2), and an alkali liquid dosing pipe (4-4) are arranged at the bottom of the first-stage aerobic tank (4). Polyurethane high-efficiency biological carrier fillers (4-3) are arranged in the first-stage aerobic tank (4). The alkali liquid dosing pipe (4-4) is connected to an alkali liquid tank (15-1) inside the chemical dosing room (15).

2. The zero-discharge system for treating high-concentration organic industrial wastewater according to claim 1, characterized in that, The first aerobic tank (4) is connected to the sewage return well (5) through the communication hole in the end wall of the first aerobic tank (4). A nitrification liquid return pump (5-1) is arranged inside the sewage return well (5), and the nitrification liquid return pump (5-1) is connected to the first nitrification liquid return pipe (3-3).

3. A zero-emission system for treating high-concentration organic industrial wastewater according to claim 1, characterized in that, The intermediate sedimentation tank (6) is located inside the sewage return well (5). The intermediate sedimentation tank (6) is connected to the second anoxic tank (7) through the communication hole in the end wall of the intermediate sedimentation tank (6). A sludge return pump (6-1) is arranged inside the intermediate sedimentation tank (6), and the sludge return pump (6-1) is connected to the sludge return pipe (3-4). Two diagonal corners of the second anoxic tank (7) are provided with bottom push-flow mixers (7-1). A combined denitrification filler (7-2) is arranged in the second anoxic tank (7). A second nitrification liquid return pipe (7-3) and an external carbon source inlet pipe (7-4) are arranged inside one end of the second anoxic tank (7). An external carbon source dosing tank (7-5) is arranged outside the second anoxic tank (7). A second nitrification liquid return pump (8-4) is arranged inside the second aerobic tank (8). The second nitrification liquid return pipe (7-3) is connected to the second nitrification liquid return pump (8-4). An external carbon source solution tank (15-2) is arranged inside the chemical dosing room 15. The external carbon source solution tank (15-2) is connected to the external carbon source inlet pipe (7-4). The second anoxic tank (7) is connected to the second aerobic tank (8) through the communication hole in the end wall of the second anoxic tank (7). A bottom aeration pipe assembly (8-1) and a bottom aeration pipe inlet pipe (8-2) are arranged at the bottom of the second aerobic tank (8).

4. A zero-discharge system for treating high-concentration organic industrial wastewater according to claim 3, characterized in that, The secondary aerobic tank (8) is connected to the secondary sedimentation tank (9) through the communication hole in the end wall of the secondary aerobic tank (8). Inside the secondary sedimentation tank (9), there is an inclined tube assembly (9-1). The secondary sedimentation tank (9) is connected to the collecting well (10) through the upper communication hole in the end wall of the secondary sedimentation tank (9). The secondary sedimentation tank (9) is connected to the sludge thickening tank (11) through the lower communication hole in the end wall of the secondary sedimentation tank (9). Inside the collecting well (10), there is a collecting well lift pump (10-1) and a collecting well lift pump pressure water pipe (10-2). The collecting well lift pump (10-1) is connected to the multi-media filter inlet pipe (16-1) on one side of the top of the multi-media filter (16) through the collecting well lift pump pressure water pipe (10-2). Inside the multi-media filter (16), there is a multi-media filter layer (16-3). At the bottom of the multi-media filter (16), there is a multi-media filter outlet pipe (16-2). The multi-media filter outlet pipe (16-2) is connected to the ultrafiltration device inlet pipe (17-1) on one side of the bottom of the ultrafiltration device (17). On one side of the top of the ultrafiltration device (17), there is an ultrafiltration device outlet pipe (17-2). Inside the ultrafiltration water tank (18), there is an ultrafiltration backwash pump (18-2). An ultrafiltration backwash pump pressure water pipe (18-21) is connected to the ultrafiltration backwash pump (18-2). The ultrafiltration device outlet pipe (17-2) is connected to the ultrafiltration backwash pump pressure water pipe (18-21). One side of the reverse osmosis lift pump (19) is connected to a reverse osmosis lift pump suction pipe (19-1), and the other side is connected to a reverse osmosis lift pump pressure water pipe (19-2). The reverse osmosis lift pump suction pipe (19-1) is connected to the ultrafiltration water tank (18). The reverse osmosis lift pump pressure water pipe (19-2) is connected to the reverse osmosis high-pressure pump suction pipe (21-1) connected to one side of the security filter (20). The other side of the security filter (20) is connected to a security filter outlet pipe (20-2) at the bottom. One side of the reverse osmosis high-pressure pump (21) is connected to a reverse osmosis high-pressure pump suction pipe (21-1), and the other side is connected to a reverse osmosis high-pressure pump pressure water pipe (21-2). The security filter outlet pipe (20-2) is connected to the reverse osmosis high-pressure pump suction pipe (21-1). The reverse osmosis high-pressure pump pressure water pipe (21-2) is connected to the reverse osmosis device inlet pipe (22-1) connected to one side of the reverse osmosis device (22). Before the security filter outlet pipe (20-2) and the reverse osmosis device inlet pipe (22-1), there are a cleaning agent dosing tank (22-4) and a scale inhibitor dosing tank (22-5). One side of the reverse osmosis device (22) is connected to a reverse osmosis device product water pipe (22-2) connected to the reverse osmosis water tank (24).

5. A zero-discharge system for treating high-concentration organic industrial wastewater according to claim 1, characterized in that, The reverse osmosis water tank (24) is connected to the disinfection and recycled water tank (25) through the communication hole in the end wall of the reverse osmosis water tank (24). A disinfection device (25-1) is connected to the disinfection and recycled water tank (25). On the side of the disinfection and recycled water tank (25) away from the reverse osmosis water tank (24), a recycled water pump (25-2) is connected through a recycled water pump suction pipe (25-21), and the other side of the recycled water pump (25-2) is connected to a recycled water pump pressure pipe (25-22).

6. A method for nearly zero discharge treatment of high-concentration organic industrial wastewater, based on the high-concentration organic industrial wastewater treatment and nearly zero discharge system according to any one of claims 1-5, characterized in that, It includes the following steps: Step 1: The high-concentration organic industrial wastewater enters the regulation tank (1) through the water inlet pipe (1-1). After slag removal by the mechanical grille (1-2), the pH is adjusted. Dilute sulfuric acid solution is added to the regulation tank through the acid liquid tank (15-3) arranged in the chemical dosing room (15) and the pH adjustment acid addition pipe (1-3) connected thereto to adjust the pH to 7-8. The residence time in the regulation tank is 12 h; The treated water with adjusted water quality and quantity flows into the hydrolysis acidification tank (2) through the communication hole in the end wall of the regulation tank (1) for hydrolysis and acidification two-stage facultative microbial reactions. The air stirring pipe (2-1) at the bottom of the tank is opened once every 4 h, and each opening lasts for 20 min to provide and maintain a dissolved oxygen of 0.3-0.5 mg / L in the hydrolysis acidification tank (2). The residence time in the hydrolysis acidification tank (2) is 8 h; The effluent from the hydrolysis acidification tank (2) enters the first-stage anoxic tank (3) through the communication hole in the end wall of the hydrolysis acidification tank. The bottom diagonal flow agitator (3-1) arranged at the bottom of the tank provides 0.5-1 mg / L of dissolved oxygen required for denitrification. The biofilm attached to the elastic three-dimensional denitrification filler (3-2) arranged in the tank forms a micro A / O unit, and there is an anoxic microenvironment inside the biofilm, which helps the denitrification reaction to proceed. The treated wastewater in the first-stage anoxic tank (3) is mixed with the nitrification liquid provided by the nitrification liquid reflux pump (5-1) arranged at the bottom of the sewage reflux well (5) and the first-stage nitrification liquid reflux pipe (3-3) connected thereto, and the first-stage microbial denitrification reaction is completed, converting NOx--N into N2 and escaping from the wastewater, and using nitro-oxidized organic matter. The nitrification liquid reflux ratio R = 3-4. The excess sludge is refluxed by the sludge reflux pump (6-1) arranged at the bottom of the intermediate sedimentation tank (6) and the sludge reflux pipe (3-4) connected thereto for phosphorus release. The sludge reflux ratio r = 1. The denitrification load of the first-stage anoxic tank (3) is 0.14 kgNOx--N / kgMLSS·d; The effluent from the first-stage anoxic tank (3) enters the first-stage aerobic tank (4) through the communication hole in the end wall of the first-stage anoxic tank (3). The bottom aerator assembly (4-1) arranged at the bottom of the tank and the air inlet pipe (4-2) of the bottom aerator assembly provide 2-4 mg / L of dissolved oxygen required for nitrification reaction. When the pH ≤ 6.3, Na2CO3 alkali solution is added through the alkali liquid tank (15-1) arranged in the chemical dosing room (15) and the alkali addition pipe (4-4) connected thereto to maintain the pH at 7-8. The nitrification load of the first-stage aerobic tank (4) is 0.10 kgNH3-N / kgMLSS·d; The effluent from the first-stage aerobic tank (4) enters the sewage return well (5) through the connecting holes on the end wall of the first-stage aerobic tank (4). Part of it is transported by the nitrification liquid return pump (5-1) installed at the bottom of the tank and the connected first-stage nitrification liquid return pipe (3-3) to the first-stage anoxic tank (3). The nitrification liquid containing nitrite bacteria and nitrate bacteria is mixed with the treated water in the tank for denitrification and nitrogen removal through denitrification. The other part enters the intermediate sedimentation tank (6). The inclined plate assembly (6-2) in the intermediate sedimentation tank separates the sludge and water from the effluent after the treatment of the first-stage anoxic tank (3) / first-stage aerobic tank (4) process. The water after sludge and water separation enters the second-stage anoxic tank (7) through the connecting holes on the end wall of the intermediate sedimentation tank (6). The surplus sludge after sludge and water separation enters the first-stage anoxic tank (3) through the sludge return pump (6-1) and the connected sludge return pipe (3-4). The surface loading of the intermediate sedimentation tank is 1.2 m³ / (㎡·h). The first-stage denitrification, phosphorus removal, and organic matter removal are carried out through the first-stage anoxic tank (3) / first-stage aerobic tank (4) process. After being treated by the first-stage anoxic tank (3) / first-stage aerobic tank (4), the effluent has a COD of 100 mg / L and a TN of 60 mg / L. Therefore, the second-stage anoxic tank (7) / second-stage aerobic tank (8) process is required for treatment. In the second-stage anoxic tank (7), the bottom push-flow mixer (7-1) installed diagonally at the bottom of the tank provides 0.5-1 mg / L of dissolved oxygen required for the microbial denitrification reaction. The combined denitrification packing (7-2) installed in the tank can provide a sufficient and stable microbial flora after biological film formation. Moreover, due to the unity and sealing of the biological film, the aerobic, anoxic, and anaerobic synergistic effects are naturally formed due to the different oxygen concentrations received by the surface, middle, and inner layers of the film body, realizing the simultaneous nitrification-denitrification reaction to improve the denitrification and phosphorus removal effects. The treated wastewater in the second-stage anoxic tank (7) is mixed with the reflux nitrification liquid provided by the second-stage nitrification liquid return pump (8-4) installed in the second-stage aerobic tank (8) and the connected second-stage nitrification liquid return pipe (7-3). Since the total nitrogen in the effluent after passing through the first-stage anoxic tank (3) / first-stage aerobic tank (4) is still 60 mg / L and mainly in the form of nitrate nitrogen; although the COD of the effluent is 100 mg / L, its biodegradability is poor. Therefore, an additional carbon source needs to be added to strengthen the denitrification effect. The additional carbon source is a high-quality plant carbon source, and the dosing amount is 1 g / h·L. The additional carbon source is dosed by the additional carbon source solution tank (15-2) installed in the chemical dosing room (15), the connected additional carbon source inlet pipe (7-4), and the additional carbon source dosing tank (7-5). Under the condition of sufficient carbon source, the second-stage microbial denitrification reaction is completed, further converting NOx--N into N2 and escaping from the wastewater, and further oxidizing organic matter with nitro. The nitrification liquid reflux ratio R = 2-3, and the denitrification load of the second-stage anoxic tank is 0.12 kgNH3-N / kgMLSS·d. The effluent from the secondary anoxic tank (7) enters the secondary aerobic tank (8) through the connecting holes in the end wall of the secondary anoxic tank (7). The dissolved oxygen required for the secondary nitrification reaction, which is 1 - 2 mg / L, is provided by the bottom aeration pipe assembly (8 - 1) and the bottom aeration pipe inlet pipe (8 - 2) arranged at the bottom of the tank. In the secondary aerobic tank (8) during the nitrification process, organic matter is first oxidized, and then ammonium is oxidized. The nitrite nitrification and nitrification proceed in series. The air - water ratio of the secondary aerobic tank (8) is 20:1, the average membrane flux is 20 L / h·㎡, and the nitrification load of the secondary aerobic tank (8) is 0.08 kgNH3 - N / kgMLSS·d; Denitrification, phosphorus removal, and the removal of organic pollutants are carried out through the secondary anoxic tank (7) / secondary aerobic tank (8) process; The effluent from the secondary aerobic tank (8) enters the secondary sedimentation tank (9) through the bottom connecting through - holes in the end wall of the secondary aerobic tank (8). The inclined tube assembly (9 - 1) separates the sludge and water from the effluent treated by the secondary anoxic tank (7) / secondary aerobic tank (8) process. The water after sludge - water separation enters the collection well (10) through the upper connecting holes in the end wall of the secondary sedimentation tank, and the excess sludge after sludge - water separation enters the sludge thickening tank (11) through the lower part of the end wall of the secondary sedimentation tank. The surface load of the secondary sedimentation tank is 1.0 m³ / (㎡·h). After being treated by the secondary anoxic tank (7) / secondary aerobic tank (8), the effluent has a COD of 50 mg / L, ammonia nitrogen of 1 mg / L, total nitrogen of 15 mg / L, and phosphorus of 0.5 mg / L; The treated water in the transfer collection well (10) enters the multi - media filter (16) through the collection well lift pump (10 - 1) arranged at the bottom of the tank, the collection well lift pump pressure pipe (10 - 2), and the multi - media filter inlet pipe (16 - 1) connected thereto. It is filtered through the composite multi - media filter layer (16 - 3) to intercept and remove suspended solids and other impurities in the water. The filtration rate of the multi - media filter is 4 - 5 m / h; The effluent from the multi - media filter (16) enters the ultra - filtration device (17) through the multi - media filter outlet pipe (16 - 2) at the bottom of the multi - media filter (16) and the ultra - filtration device inlet pipe (17 - 1) at the bottom of the ultra - filtration device (17) connected thereto, intercepting macromolecular substances with a diameter of 0.01 - 0.1 μm to meet the water quality requirements for the reverse osmosis membrane inlet. The ultra - filtration device (17) needs to be backwashed every 1 h of operation. The backwash water is provided by the ultra - filtration backwash pump (18 - 2) and the ultra - filtration backwash pump pressure pipe (18 - 21) arranged at the bottom of the ultra - filtration water tank (18). The static pressure of the ultra - filtration device is 0.1 - 0.5 MPa; The effluent from the ultra - filtration device (17) enters the ultra - filtration water tank (18) through the ultra - filtration device outlet pipe (17 - 2) arranged at the upper part, and then is lifted to the security filter (20) through the reverse osmosis lift pump suction pipe (19 - 1), the reverse osmosis lift pump (19), and the reverse osmosis lift pump pressure pipe (19 - 2) for filtration by the polypropylene PP melt - blown filter element to intercept and remove particles between 0.03 - 100 μm to protect the reverse osmosis membrane in the subsequent process; The water output from the security filter (20) passes through the security filter outlet pipe (20-2) provided at the lower part, the reverse osmosis high-pressure pump suction pipe (21-1) connected thereto, the reverse osmosis high-pressure pump (21), the reverse osmosis high-pressure pump pressure pipe (21-2), and the reverse osmosis unit inlet pipe (22-1) at the upper part of the head end of the reverse osmosis unit (22) and enters the reverse osmosis unit (22). Small molecule solutes, organic impurities, and dissolved inorganic salts with a retention component of 1-10 Å are intercepted. When the membrane flux drops by 10%-15% and the conductivity of the permeated water increases by 5%-10%, the reverse osmosis membrane needs to be cleaned. The cleaning agent is MCT410 and is added through the cleaning agent dosing tank (22-4). The scale inhibitor is EWT620 and is added through the scale inhibitor dosing tank (22-5). The water treated by the reverse osmosis unit (22) enters the reverse osmosis water tank (24) through the reverse osmosis unit product water pipe (22-2) provided at the end of the reverse osmosis unit (22). The reverse osmosis unit uses an aromatic polyamide membrane, with a designed flux of 20.0 L / (㎡·h) and an operating pressure of 1.55 MPa; The water output from the reverse osmosis water tank (24) enters the disinfection and reused water tank (25) through the communication hole in the end wall of the reverse osmosis water tank (24), is disinfected by the disinfection equipment (25-1), and after the water output meets the industrial water reuse or industrial cooling circulating water quality standard, it is connected to the internal industrial water pipe network of the factory through the reused water pump suction pipe (25-21), the reused water pump (25-2), and the reused water pump pressure pipe (25-22); Step 2: The surplus sludge separated from the sludge and water in the secondary sedimentation tank (9) enters the sludge thickening tank (11) through the communication hole at the bottom of the end of the secondary sedimentation tank (9). The residence time in the sludge thickening tank is 16 h. The thickened sludge is transported to the plate and frame filter press (12-2) through the screw pump sludge suction pipe (11-1) and the screw pump (12-1) provided in the plate and frame filter press room (12) to be filtered into sludge with a moisture content of 70-75%. The filtered sludge is sent by a conveyor belt to the mixing and stirring machine (13-1) provided in the functional organic fertilizer manufacturing room (13), and a heavy metal composite stabilizer and a sludge conditioner are added. The heavy metal composite stabilizer consists of 50% fly ash, 16.7% ferric chloride, 16.7% polyaluminum sulfate, and 16.6% formamidine, and the dosing amount is 0.02 kg / m³ of sludge. The sludge conditioner consists of organic carbon bacteria liquid and enzyme, and the dosing amounts are 3 kg / m³ and 0.01 kg / m³ of sludge respectively. After mixing and stirring for 5 minutes, it is transported to a small and rapid composting machine (13-2) and made into functional organic fertilizer with a particle size of 1.0-2.0 mm through the fermentation process, and finally packaged by a screening and packaging machine (13-3); Step 3: The method is that the concentrated water generated by the reverse osmosis process for the advanced treatment of water is evaporated by MVR, and the evaporation concentrate is used for the dehumidification and slag removal section; The concentrated water generated by the reverse osmosis device (22) during the water treatment process enters the MVR evaporator (23) through the reverse osmosis device concentrated water pipe (22-3) and the MVR evaporator feed pipe (23-1) connected thereto for evaporation crystallization treatment. The condensed water generated during the evaporation crystallization process enters the multi-media filter (16) through the condensate pipe (23-3) and the multi-media filter water inlet pipe (16-1) connected thereto. The evaporation crystallization concentrate is discharged through the concentrate discharge pipe (23-2) and used in the dehumidification and slag removal section.

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