Comprehensive wastewater treatment system

Abstract

The utility model relates to the technical field of wastewater treatment, in particular to a comprehensive wastewater treatment system which comprises a pretreatment system and a biochemical treatment system, and the pretreatment system comprises a trifluoroacetic acid treatment unit, a fermentation wastewater treatment unit, an acetonitrile wastewater treatment unit and a low-concentration production wastewater treatment unit; the fermentation wastewater treatment unit comprises a collection tank, a front dephosphorization reaction tank and a front dephosphorization sedimentation tank which are connected in sequence, and a water outlet pipe of the front dephosphorization sedimentation tank is connected with a buffer tank; the acetonitrile wastewater treatment unit comprises a collecting tank, an alkaline hydrolysis reactor, a multi-dimensional electrolytic tank and a photocatalytic oxidation reaction tank which are connected in sequence; the low-concentration production wastewater treatment unit comprises a collection tank, a neutralization reaction tank and a neutralization sedimentation tank which are connected in sequence, and a water outlet pipe of the neutralization sedimentation tank is connected with the comprehensive regulation tank. On the basis of relatively economical biochemical treatment, classification pretreatment is carried out according to difficult-to-treat components in the wastewater, so that the biochemical treatment effect is ensured, and the wastewater is stably discharged in a standard reaching manner.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment, in particular to a comprehensive wastewater treatment system. Background Art

[0002] Wastewater treatment refers to the use of physical, chemical and biological methods to treat wastewater, purify wastewater, reduce pollution, and achieve the purpose of wastewater recycling or wastewater discharge in compliance with standards. Wastewater can be divided into industrial wastewater, domestic sewage, commercial sewage and agricultural sewage according to its source and composition. In the actual treatment process, there are many wastewater discharge points and the water quality composition is complex, which can contain many different types of wastewater at the same time. For example, the wastewater of a biopharmaceutical company treated by our company mainly includes wastewater from the production of pharmaceutical intermediates, equipment cleaning wastewater, factory floor cleaning wastewater, and domestic sewage. Domestic sewage mainly comes from drainage in the factory cafeteria, toilets, bathrooms, etc.

[0003] Among them, production wastewater includes fermentation pharmaceutical wastewater, which mainly comes from the separation of bacterial residues, extraction and refining of drugs, recovery of solutions, equipment, ground washing water and other processes. The pollutant concentration in the wastewater is high and the water volume is large. The components contained in the wastewater are mainly fermentation residues, demulsifiers, residual antibiotics and their degradation products, as well as various organic solvents and some inorganic salt substances remaining in the antibiotic extraction process; its wastewater composition is complex, the carbon-nitrogen nutrient ratio is unbalanced (nitrogen source excess), Cl- and suspended solids content is high, the wastewater has a heavy color and odor, is easy to produce foam, contains difficult-to-degrade substances and antibiotics with antibacterial effects, resulting in toxicity to microorganisms and difficulty in biochemical degradation. In addition, the pollutant components in production wastewater also include: sodium acetate, acetic acid, ammonium acetate, methanol, ethanol, inorganic and organic salts, etc. The wastewater is characterized by high COD, NH3-N, and total phosphorus concentrations, and contains high concentrations of characteristic pollutants acetonitrile and trifluoroacetic acid.

[0004] In summary, the terminal wastewater is an organic wastewater with complex water quality and difficult to treat. The traditional treatment method for this type of wastewater is to classify the wastewater according to the COD concentration, and then adopt different pretreatment methods. For example, the Chinese invention patent with publication number CN105060627B provides a comprehensive treatment system for chemical pharmaceutical wastewater, which divides the wastewater into ultra-high concentration wastewater, high concentration wastewater, and low concentration wastewater, and then pretreats the wastewater of different concentrations to improve the biodegradability of the wastewater. However, the method still has the following technical problems in actual use: although the COD removal rate in the pretreatment stage can be improved by classifying and pretreating according to the COD content, the treatment effect is not ideal for production wastewater with a high phosphorus concentration and wastewater containing characteristic pollutants such as trifluoroacetic acid.

[0005] Therefore, the present application provides a comprehensive wastewater treatment system, which is based on relatively economical biochemical treatment and classifies and pre-treats the difficult-to-treat components in the wastewater, thereby ensuring the biochemical treatment effect and stable discharge of wastewater that meets the standards. Utility Model Content

[0006] The utility model provides a comprehensive wastewater treatment system, which is based on relatively economical biochemical treatment and performs classified pretreatment according to the difficult-to-treat components in the wastewater, thereby ensuring the biochemical treatment effect and stable discharge of wastewater up to standard.

[0007] This application provides the following technical solutions:

[0008] The comprehensive wastewater treatment system comprises a pretreatment system and a biochemical treatment system. The pretreatment system comprises a trifluoroacetic acid treatment unit, a fermentation wastewater treatment unit, an acetonitrile wastewater treatment unit, a low-concentration production wastewater treatment unit and a domestic sewage treatment unit. The trifluoroacetic acid treatment unit comprises a trifluoroacetic acid neutralization tank, and the outlet pipe of the trifluoroacetic acid neutralization tank is connected to a comprehensive regulating tank; the fermentation wastewater treatment unit comprises a fermentation wastewater collection tank, a pre-phosphorus removal reaction tank and a pre-phosphorus removal sedimentation tank which are connected in sequence, and the outlet pipe of the pre-phosphorus removal sedimentation tank is connected to a buffer tank; the acetonitrile wastewater treatment unit comprises an acetonitrile wastewater collection tank, an alkaline hydrolysis reactor, a multi-dimensional electrolytic tank and a photocatalytic oxidation reaction tank which are connected in sequence, and the outlet pipe of the photocatalytic oxidation reaction tank is connected to the buffer tank; the low-concentration production wastewater treatment unit comprises a low-concentration production wastewater collection tank, a neutralization reaction tank and a neutralization sedimentation tank which are connected in sequence, and the outlet pipe of the neutralization sedimentation tank is connected to the comprehensive regulating tank; the outlet pipe of the buffer tank is also connected to a coagulation flotation device, and the coagulation flotation device is connected to the comprehensive regulating tank.

[0009] Technical principles and beneficial effects: The pretreatment system classifies wastewater according to its characteristics, which is conducive to distinguishing the primary and secondary among various types of wastewater, highlighting the key points, and then strengthening the pretreatment process to ensure the biochemical treatment effect, and improve the removal rate of various pollutants, ensuring that wastewater discharge is stable and meets the standards.

[0010] 1. According to the Regulations on the Safety Management of Hazardous Chemicals, trifluoroacetic acid is a hazardous chemical. If it enters the sewage treatment plant directly, according to the National List of Hazardous Wastes HW45, the sludge in the sewage treatment plant will become hazardous waste containing organic halides. Trifluoroacetic acid cannot be removed from the water body by general chemical and biological methods. Therefore, it is necessary to neutralize and remove the trifluoroacetic acid wastewater separately in the pretreatment stage, and then pass it into the comprehensive regulating tank to ensure the safety of the subsequent biochemical sludge.

[0011] 2. The average total phosphorus concentration in fermentation wastewater is high. Setting up a pre-phosphorus removal reaction tank and a sedimentation tank in the pretreatment stage can optimize the biochemical treatment efficiency. If it enters the biochemical system without pretreatment, it may stimulate excessive microbial reproduction and affect the stability and treatment efficiency of the biochemical system. In addition, pretreatment phosphorus removal can significantly reduce the phosphorus load entering deep treatment or further biochemical treatment, thereby reducing the pressure on subsequent treatment facilities and reducing operating costs.

[0012] 3. Acetonitrile wastewater has poor biodegradability and usually cannot be directly biochemically treated. Acetonitrile is difficult to oxidize and is toxic, which will affect the growth and biological treatment of microorganisms, resulting in unsatisfactory biochemical treatment effects of nitrile-containing wastewater. The present application adopts alkaline hydrolysis + multi-dimensional electrolysis + photocatalytic oxidation to jointly treat acetonitrile wastewater: the first step is to utilize the hydrolysis characteristics of acetonitrile, and use a higher temperature under alkaline conditions to break the double bonds of the nitrile, converting them into acetic acid and ammonia nitrogen, and a small amount of them into inorganic cyanide; the second step is to use multi-dimensional electrolysis to destroy cyanide in the wastewater by electrochemical oxidation reaction. Under the electrolysis voltage, cyanide ions in the wastewater lose electrons at the anode and are oxidized into carbon dioxide, nitrogen or ammonia; the third step is to use hydrogen peroxide as an oxidant to oxidize the residual cyanide into cyanate for the cyanide that was not completely removed in the first two steps, and finally hydrolyze it into carbonate and ammonia; thereby improving the biodegradability of the wastewater.

[0013] 4. Low-concentration production wastewater treatment unit is mainly used to collect waste alkali liquor, cleaning wastewater and process wastewater. This type of wastewater has a low COD concentration, a certain fluctuation in pH value, and contains a certain amount of suspended solids. Neutralization and precipitation treatment before entering the biochemical process can adjust the pH value of the wastewater to the optimal range suitable for the survival and activity of microorganisms to ensure the stable operation of the biochemical system; in addition, colloids or tiny particles will be produced after the neutralization reaction. The addition of coagulants can cause these particles to coagulate and grow together to form large-particle flocs that are easy to settle, thereby effectively removing suspended solids through the sedimentation tank, reducing the load of subsequent biochemical treatment units, and also helping to improve the effluent quality.

[0014] Furthermore, it also includes a deep processing unit, which is arranged after the biochemical treatment system. The deep processing unit includes an MBBR reaction tank, a final sedimentation tank, a terminal phosphorus removal reaction tank and a terminal phosphorus removal sedimentation tank connected in sequence, and a clear water tank is arranged after the terminal phosphorus removal sedimentation tank.

[0015] Beneficial effects: In the wastewater discharge requirements, a high requirement is placed on the removal rate of total phosphorus (removal rate ≥ 96%). In order to ensure that the effluent continuously meets the standards, this application conducts deep treatment at the end, and adopts chemical precipitation as a control measure for phosphate compliance; a portion of the phosphate has been removed in the pretreatment stage, and chemical precipitation is used at the end to assist in phosphorus removal. The phosphate is precipitated by adding a phosphorus removal agent and then separated from the wastewater. The remaining phosphorus is completely removed through precipitation and adsorption.

[0016] Furthermore, the biochemical treatment system includes a hydrolysis acidification tank, a UASB anaerobic reactor, an anaerobic sedimentation tank, an anoxic tank, a PACT aerobic tank, and a secondary sedimentation tank which are connected in sequence.

[0017] Beneficial effects: The biochemical treatment system adopts a combined process of hydrolysis acidification + UASB anaerobic reaction + A / O (anoxic + aerobic) biochemical process. During the biochemical treatment process, complex macromolecular organic matter is converted into small molecular organic matter through hydrolysis acidification, thereby improving the biodegradability of wastewater and facilitating subsequent biochemical treatment. In the UASB anaerobic section, the advantages of UASB such as high volumetric load, high removal efficiency and strong impact resistance are fully utilized to significantly degrade COD organic pollutants. In the A / O section, organic matter removal and denitrification are simultaneously completed, thereby improving effluent quality, reducing the inhibitory effect of toxic and harmful substances on biological oxidation, and improving sludge settling performance.

[0018] Furthermore, a reflux pump and a reflux pipe are provided at the water outlet of the hydrolysis acidification tank, and the water outlet end of the reflux pipe is connected to the water inlet end of the hydrolysis acidification tank.

[0019] Beneficial effects: The effluent from the hydrolysis acidification tank is used to dilute the influent, thereby reducing the concentration of toxic substances in the influent, which is beneficial to reducing the impact load on the biochemical system.

[0020] Furthermore, a reflux pump and a reflux pipe are provided at the water outlet of the clear water tank, and the water outlet end of the reflux pipe is respectively connected to the water inlet of the comprehensive regulating tank and the water inlet of the UASB anaerobic reactor.

[0021] Beneficial effects: Using the effluent from the clear water tank to dilute the inlet water of the comprehensive regulating tank and the UASB anaerobic reactor is beneficial to reducing the wastewater concentration and reducing the impact load of the biochemical system.

[0022] Furthermore, the low-concentration production wastewater collection tank is connected to the PACT aerobic tank through a pipeline.

[0023] Beneficial effects: It is conducive to optimizing the treatment process, saving energy and costs, and ensuring the treatment effect; this application directly sends part of the wastewater from the low-concentration production wastewater collection pool into the PACT aerobic pool for faster biodegradation treatment, thereby improving the efficiency of the entire treatment process.

[0024] Furthermore, it also includes a physicochemical sludge thickening tank and a biochemical sludge thickening tank. The sewage pipes of the neutralization sedimentation tank, the pre-phosphorus removal sedimentation tank, and the coagulation and flotation device are all connected to the physicochemical sludge thickening tank; the sewage pipes of the UASB reaction tank, the anaerobic sedimentation tank, the anoxic tank, the PACT aerobic tank, the secondary sedimentation tank, the MBBR reaction tank, the final sedimentation tank, and the terminal phosphorus removal sedimentation tank are all connected to the biochemical sludge thickening tank; the filter pipe of the biochemical sludge thickening tank is connected to the inlet of the comprehensive regulating tank.

[0025] Furthermore, the comprehensive regulating tank is provided with a controller and a pre-aeration fan, a PH online detector, and an acid and alkali solution adding unit electrically connected to the controller. When the PH online detector detects that the PH value in the comprehensive regulating tank exceeds a preset control range, the PH online detector alarms and transmits a signal to the controller, and the controller controls the acid and alkali solution adding unit to add reagents.

[0026] Beneficial effects: All pre-treated wastewater enters the comprehensive regulating pool. Since some wastewater has a high content of pollutants, the pollutants are diluted in the process of regulating various types of wastewater, which is conducive to improving the efficiency of subsequent biochemical treatment:

[0027] 1. By setting a pre-aeration fan in the comprehensive regulating pool and controlling the pre-aeration fan to intermittently aerate the comprehensive regulating pool through a controller, the equalization effect of the regulating pool on water quality can be enhanced.

[0028] 2. By setting up a pH online detector and an acid and alkali solution dosing unit, various types of wastewater are naturally neutralized in the comprehensive regulating tank. When the pH exceeds the control range (6-9), the pH online detector alarms, and the controller controls the acid and alkali solution dosing unit to automatically add acid (or alkali solution) to adjust the pH value.

[0029] 3. Since the pH value of different wastewaters varies greatly, the pH value of the wastewater can be stabilized within an appropriate range by automatically controlling the addition of alkali or acid, which is conducive to the refinement of control measures and thus ensures the overall treatment effect.

[0030] Furthermore, a multi-layer electrode plate is arranged in the multi-dimensional electrolytic cell, and active granular fillers are filled between the multi-layer electrode plates.

[0031] Beneficial effects: The surface of the loaded particles can be charged, the distance between the two plates can be reduced, a multi-dimensional electrode can be formed, the total surface ratio of the electrode can be increased, and the mass transfer effect can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the connection structure of the pretreatment system of the utility model;

[0033] Figure 2 This is a schematic diagram of the connection structure of the biochemical treatment system of the utility model;

[0034] Figure 3 This is a schematic diagram of the connection structure of the deep processing unit of the utility model. DETAILED DESCRIPTION

[0035] The following is further described in detail through specific implementation methods:

[0036] The symbols in the drawings of the specification include: trifluoroacetic acid treatment unit 1, fermentation wastewater treatment unit 2, fermentation wastewater collection tank 21, pre-phosphorus removal reaction tank 22, pre-phosphorus removal sedimentation tank 23, acetonitrile wastewater treatment unit 3, alkaline hydrolysis reactor 31, multi-dimensional electrolytic cell 32, photocatalytic oxidation reaction tank 33, buffer tank 4, coagulation flotation device 5, low-concentration production wastewater treatment unit 6, low-concentration production wastewater collection tank 61, neutralization reaction tank 62, neutralization sedimentation tank 63, domestic sewage treatment unit 7, comprehensive regulating tank 8, physicochemical sludge concentration tank 9, hydrolysis acidification tank 10, biochemical sludge concentration tank 101, UASB anaerobic reactor 11, anaerobic sedimentation tank 12, anoxic tank 13, PACT aerobic tank 14, secondary sedimentation tank 15, MBBR reaction tank 16, final sedimentation tank 17, terminal phosphorus removal reaction tank 18, terminal phosphorus removal sedimentation tank 19, and clear water tank 20.

[0037] Example

[0038] like Figure 1 As shown, the comprehensive wastewater treatment system includes a pretreatment system and a biochemical treatment system. The pretreatment system includes a trifluoroacetic acid treatment unit 1, a fermentation wastewater treatment unit 2, an acetonitrile wastewater treatment unit 3, a low-concentration production wastewater treatment unit 6 and a domestic sewage treatment unit 7. The trifluoroacetic acid treatment unit 1 includes a trifluoroacetic acid neutralization tank, and the outlet pipe of the trifluoroacetic acid neutralization tank is connected to a comprehensive regulating tank 8; the trifluoroacetic acid waste liquid is discharged to the trifluoroacetic acid neutralization tank through a pipeline, and is discharged to the comprehensive regulating tank 8 after being neutralized by adding liquid alkali.

[0039] The acetonitrile wastewater treatment unit 3 includes an acetonitrile wastewater collection tank, an alkaline hydrolysis reactor 31, a multidimensional electrolytic cell 32 and a photocatalytic oxidation reaction tank 33 connected in sequence; the acetonitrile wastewater enters the acetonitrile wastewater collection tank from the plant area, and the water quality and water quantity of the wastewater are adjusted by aeration and stirring, and enters the alkaline hydrolysis reactor 31 through a lifting pump, and liquid alkali is added to the alkaline hydrolysis reactor 31 to control the pH>12, and the temperature is controlled>90 degrees Celsius by steam heating, and the reaction time is controlled>5h. In the alkaline hydrolysis reactor 31, the acetonitrile is alkaline-hydrolyzed into acetic acid, ammonia nitrogen and a small amount of inorganic cyanide; the acetonitrile wastewater after alkaline hydrolysis flows into the multidimensional electrolytic cell 32 by gravity, and undergoes oxidation, reduction, condensation and other effects The molecular structure of organic cyanide is changed so that the organic cyanide is broken and decomposed into carbon dioxide and nitrogen. Specifically, a multi-layer electrode plate (not shown in the figure) is arranged in the multi-dimensional electrolytic cell 32 of this embodiment, and active granular fillers are loaded between the multi-layer electrode plates, so that the surface of the loaded particles can be charged, and the distance between the two electrode plates is reduced to form a multi-dimensional electrode, so that the total surface ratio of the electrode is increased and the mass transfer effect is improved; finally, the wastewater enters the photocatalytic oxidation reaction tank 33, and the non-selective characteristics of OH· (hydroxyl radicals) are used to degrade the residual cyanide, thereby reducing its inhibitory effect on microorganisms, creating conditions for the biochemical system to effectively degrade organic pollutants.

[0040] The fermentation wastewater treatment unit 2 includes a fermentation wastewater collection tank 21, a pre-phosphorus removal reaction tank 22, a pre-phosphorus removal sedimentation tank 23, the outlet pipe of the pre-phosphorus removal sedimentation tank 23 is connected to a buffer tank 4, the outlet pipe of the photocatalytic oxidation reaction tank 33 is also connected to the buffer tank 4, the outlet pipe of the buffer tank 4 is also connected to the coagulation flotation device 5, and the coagulation flotation device 5 is connected to the comprehensive regulating tank 8. The fermentation wastewater is transported to the pre-phosphorus removal reaction tank 22 by a lifting pump, and lime, flocculants and other phosphorus removal agents are added to the pre-phosphorus removal reaction tank 22 to remove most of the phosphates and sulfates in the wastewater, and then enters the buffer tank 4 after precipitation in the sedimentation tank, and then mixes with the pre-treated acetonitrile wastewater, enters the coagulation flotation device 5 to remove slag and oil substances, and after reducing the concentration of suspended matter, flows to the comprehensive regulating tank 8 by gravity.

[0041] The low-concentration production wastewater treatment unit 6 includes a low-concentration production wastewater collection tank 61, a neutralization reaction tank 62, and a neutralization sedimentation tank 63 which are connected in sequence. The outlet pipe of the neutralization sedimentation tank 63 is connected to the comprehensive regulating tank 8; the low-concentration production wastewater collection tank 61 is used to collect alkali-containing, cleaning and process wastewater. This type of wastewater has a low COD concentration, a certain fluctuation in pH value, and contains a certain amount of suspended matter. Neutralization and sedimentation treatment before entering the biochemical system can adjust the pH value of the wastewater to the optimal range suitable for the survival and activity of microorganisms to ensure the stable operation of the biochemical system; in addition, colloids or tiny particles will be produced after the neutralization reaction. The addition of coagulants can promote these particles to coagulate and grow together to form large particle flocs that are easy to settle, thereby effectively removing suspended solids through the sedimentation tank, reducing the load of subsequent biochemical treatment units, and also helping to improve the effluent water quality.

[0042] The domestic sewage treatment unit 7 includes a domestic sewage collection tank, which is connected to a comprehensive regulating tank 8, and the comprehensive regulating tank 8 is used to mix pre-treated trifluoroacetic acid wastewater, fermentation wastewater, acetonitrile wastewater, low-concentration production wastewater and domestic sewage. In this embodiment, the comprehensive regulating tank 8 is provided with a controller and a pre-aeration fan electrically connected to the controller, a PH online detector, and an acid-base solution adding unit (not shown in the figure). When the PH online detector detects that the PH value in the comprehensive regulating tank 8 exceeds the preset control range value, the PH online detector alarms and transmits a signal to the controller, and the controller controls the acid-base solution adding unit to add the agent; specifically, the controller can adopt a PLC controller, and the acid-base solution adding unit includes a reagent box, a metering pump and a connecting pipeline.

[0043] The present application sets a pre-aeration fan in the comprehensive regulating tank 8, and controls the pre-aeration fan to intermittently aerate the comprehensive regulating tank 8 through a controller, so as to strengthen the equalization effect of the regulating tank on the water quality; by setting a pH online detector and an acid and alkali solution addition unit, various types of wastewater are naturally neutralized in the comprehensive regulating tank 8. When the pH exceeds the control range (6 to 9), the pH online detector alarms, and at the same time, the controller controls the acid and alkali solution addition unit to automatically add acid (or alkali solution) to adjust the pH value, which is conducive to the refinement of control measures and thus ensures the overall treatment effect.

[0044] like Figure 2 As shown, the biochemical treatment system includes a hydrolysis acidification tank 10, a UASB anaerobic reactor 11, an anaerobic sedimentation tank 12, an anoxic tank 13, a PACT aerobic tank 14, and a secondary sedimentation tank 15 connected in sequence; Figure 3 As shown, it also includes a deep processing unit, which is arranged after the biochemical treatment system. The deep processing unit includes an MBBR reaction tank 16, a final sedimentation tank 17, a terminal phosphorus removal reaction tank 18 and a terminal phosphorus removal sedimentation tank 19 connected in sequence, and a clear water tank 20 is arranged after the terminal phosphorus removal sedimentation tank 19. Specifically, in this embodiment, the outlet of the clear water tank 20 is provided with a reflux pump and a reflux pipe (not shown in the figure), and the outlet end of the reflux pipe is respectively connected to the water inlet of the comprehensive regulating tank 8 and the water inlet of the UASB anaerobic reactor 11. The effluent of the clear water tank 20 is used to dilute the inlet of the comprehensive regulating tank 8 and the UASB anaerobic reactor 11, which is conducive to reducing the concentration of wastewater and reducing the impact load of the biochemical system; in addition, part of the wastewater in the low-concentration production wastewater collection tank 61 can also be connected to the PACT aerobic tank 14 through a pipeline (not shown in the figure), which is conducive to optimizing the treatment process, saving energy and cost, and ensuring the treatment effect.

[0045] After the wastewater is homogenized in the comprehensive regulating tank 8 for water quality and quantity, it enters the hydrolysis and acidification tank 10. In the hydrolysis and acidification tank 10, hydrolysis and acidification of organic matter mainly occur. At the same time, due to the metabolic action of hydrolysis and fermentation bacteria, large-molecule organic matter is degraded into small-molecule organic matter, thereby improving the biodegradability of the effluent and removing the COD of the sewage to a certain extent. Specifically, in the present embodiment, the outlet of the hydrolysis and acidification tank 10 is provided with a reflux pump and a reflux pipe (not shown in the figure), and the outlet end of the reflux pipe is connected to the inlet end of the hydrolysis and acidification tank 10. The effluent of the hydrolysis and acidification tank 10 is used to dilute the inlet water, thereby reducing the concentration of toxic substances in the inlet water, which is beneficial to reducing the impact load of the biochemical system.

[0046] The effluent from the hydrolysis acidification tank 10 enters the UASB anaerobic reactor 11, and most of the organic matter in the wastewater is removed through high-load anaerobic treatment. The UASB anaerobic reactor 11 promotes the full mixing of sewage and sludge through water distribution and hydraulic internal circulation stirring, and is equipped with sampling holes to analyze indicators such as sludge concentration, VFA, pH value (alkalinity) to control the operation of the UASB anaerobic reactor 11. After the wastewater is precipitated in the anaerobic sedimentation tank 12, the supernatant water enters the A / O system. The A / O system is equipped with an anoxic tank 13 and a PACT aerobic tank 14. The tank type is a completely mixed type. A submersible mixer is installed in the anoxic tank 13. The effluent flows by gravity to the PACT aerobic tank 14. The PACT aerobic tank 14 is a plug flow type. An air distribution system is installed at the bottom of the tank and aeration is adopted. The mixed liquid of the PACT aerobic tank 14 flows by gravity to the secondary sedimentation tank 15. The secondary sedimentation tank 15 is a vertical flow sedimentation tank. After sedimentation, the supernatant liquid is collected in the overflow tank around the tank and then flows out of the tank by gravity. The sludge at the bottom of the secondary sedimentation tank 15 is transported to the anoxic tank 13, the PACT aerobic tank 14, etc. by an external reflux pump.

[0047] The effluent from the secondary sedimentation tank 15 enters the MBBR reaction tank 16, and the degradation effect of the target pollutants is improved by culturing different special and advantageous bacteria in a step-by-step manner. The high-load biomass ensures the high efficiency and stability of the MBBR process in removing pollutants. The effluent from the MBBR reaction tank 16 passes through the final sedimentation tank 17, and the supernatant enters the terminal phosphorus removal reaction tank 18, the terminal phosphorus removal sedimentation tank 19, and the clear water tank 20 in turn. In the terminal phosphorus removal reaction tank 18, a phosphorus removal agent is added to precipitate phosphate and then separate it from the wastewater. The remaining phosphorus is completely removed through precipitation and adsorption.

[0048] It also includes a physicochemical sludge thickening tank 9 and a biochemical sludge thickening tank 101. The sewage pipes of the neutralization sedimentation tank 63, the pre-phosphorus removal sedimentation tank 23, and the coagulation flotation device 5 are all connected to the physicochemical sludge thickening tank 9; the sewage pipes of the anaerobic sedimentation tank 12, the secondary sedimentation tank 15, the final sedimentation tank 17, and the terminal phosphorus removal sedimentation tank 19 are all connected to the biochemical sludge thickening tank 101; the filter pipe of the biochemical sludge thickening tank 101 is connected to the inlet of the comprehensive regulating tank 8 (not shown in the figure).

[0049] Using the above wastewater treatment system, the effect data of each treatment stage are obtained, as shown in Table 1 below:

[0050] Table 1:

[0051]

[0052]

[0053] Among them, the discharge standard of acetonitrile wastewater complies with the discharge requirements for acetonitrile wastewater in GB21907-2008 "Water Pollutant Discharge Standard for Bioengineering Pharmaceutical Industry", and the discharge of COD, NH3-N and phosphorus-containing wastewater complies with the wastewater discharge requirements of the park.

[0054] In summary, the comprehensive wastewater treatment system provided in the present application is used to treat mixed wastewater containing trifluoroacetic acid waste liquid, fermentation wastewater, acetonitrile wastewater, and low-concentration production wastewater. The system drainage can stably meet the sewage discharge standards. It is an effective comprehensive wastewater treatment method that combines treatment cost, treatment efficiency and biochemical treatment effect.

[0055] The above is only an embodiment of the utility model. The utility model is not limited to the field involved in this implementation case. The common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the utility model, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the utility model and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A comprehensive wastewater treatment system, including a pretreatment system and a biochemical treatment system, characterized in that: The pretreatment system comprises a trifluoroacetic acid treatment unit, a fermentation wastewater treatment unit, an acetonitrile wastewater treatment unit, a low-concentration production wastewater treatment unit and a domestic sewage treatment unit. The trifluoroacetic acid treatment unit comprises a trifluoroacetic acid neutralization tank, and the outlet pipe of the trifluoroacetic acid neutralization tank is connected to a comprehensive regulating tank; the fermentation wastewater treatment unit comprises a fermentation wastewater collection tank, a pre-phosphorus removal reaction tank, and a pre-phosphorus removal sedimentation tank connected in sequence, and the outlet pipe of the pre-phosphorus removal sedimentation tank is connected to a buffer tank; the acetonitrile wastewater treatment unit comprises an acetonitrile wastewater collection tank, an alkaline hydrolysis reactor, a multi-dimensional electrolytic tank and a photocatalytic oxidation reaction tank connected in sequence, and the outlet pipe of the photocatalytic oxidation reaction tank is connected to the buffer tank; the low-concentration production wastewater treatment unit comprises a low-concentration production wastewater collection tank, a neutralization reaction tank, and a neutralization sedimentation tank connected in sequence, and the outlet pipe of the neutralization sedimentation tank is connected to the comprehensive regulating tank; the outlet pipe of the buffer tank is also connected to a coagulation flotation device, and the coagulation flotation device is connected to the comprehensive regulating tank.

2. The integrated wastewater treatment system according to claim 1, characterized in that: It also includes a deep treatment unit, which is arranged after the biochemical treatment system. The deep treatment unit includes an MBBR reaction tank, a final sedimentation tank, a terminal phosphorus removal reaction tank and a terminal phosphorus removal sedimentation tank connected in sequence, and a clear water tank is arranged after the terminal phosphorus removal sedimentation tank.

3. The integrated wastewater treatment system according to claim 2, characterized in that: The biochemical treatment system comprises a hydrolysis acidification tank, a UASB anaerobic reactor, an anaerobic sedimentation tank, an anoxic tank, a PACT aerobic tank, and a secondary sedimentation tank which are connected in sequence.

4. The integrated wastewater treatment system according to claim 3, characterized in that: The water outlet of the hydrolysis acidification tank is provided with a reflux pump and a reflux pipe, and the water outlet end of the reflux pipe is connected to the water inlet end of the hydrolysis acidification tank.

5. The integrated wastewater treatment system according to claim 4, characterized in that: The water outlet of the clean water tank is provided with a reflux pump and a reflux pipe, and the water outlet end of the reflux pipe is respectively connected to the water inlet of the comprehensive regulating tank and the water inlet of the UASB anaerobic reactor.

6. The integrated wastewater treatment system according to claim 5, characterized in that: The low-concentration production wastewater collection pool is connected to the PACT aerobic pool through a pipeline.

7. The integrated wastewater treatment system according to claim 6, characterized in that: It also includes a physicochemical sludge thickening tank and a biochemical sludge thickening tank. The sewage pipes of the neutralization sedimentation tank, the pre-phosphorus removal sedimentation tank, and the coagulation and flotation device are all connected to the physicochemical sludge thickening tank; the sewage pipes of the UASB reaction tank, the anaerobic sedimentation tank, the anoxic tank, the PACT aerobic tank, the secondary sedimentation tank, the MBBR reaction tank, the final sedimentation tank, and the terminal phosphorus removal sedimentation tank are all connected to the biochemical sludge thickening tank; the filter pipe of the biochemical sludge thickening tank is connected to the inlet of the comprehensive regulating tank.

8. The integrated wastewater treatment system according to claim 7, characterized in that: The comprehensive regulating tank is provided with a controller and a pre-aeration fan, a PH online detector, and an acid and alkali solution adding unit electrically connected to the controller. When the PH online detector detects that the PH value in the comprehensive regulating tank exceeds a preset control range value, the PH online detector alarms and transmits a signal to the controller, and the controller controls the acid and alkali solution adding unit to add reagents.

9. The integrated wastewater treatment system according to claim 1, characterized in that: The multi-dimensional electrolytic cell is provided with multiple layers of electrode plates, and active granular fillers are filled between the multiple layers of electrode plates.

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