Thermal Process PVDF Ultrafiltration Membrane Production Wastewater Treatment Device and Treatment Method

Abstract

The present invention relates to a treatment device and a treatment method for the wastewater produced in the production of PVDF ultrafiltration membranes by the thermal method. In view of the characteristics that the wastewater produced in the production of PVDF ultrafiltration membranes by the thermal method contains high COD, SS and oils, firstly, a pretreatment system is used to remove part of COD, SS and oils; then, a biochemical treatment system is used to degrade and remove most of COD, BOD, SS, NH3-N, TP and oils; finally, a deep treatment system is used to further reduce the COD in the water. The discharged water meets and exceeds the discharge standard limit of Class A of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants (GB18918-2002), realizing up-to-standard discharge or reuse.

Description

Technical Field

[0001] The present invention is a treatment device and treatment method for wastewater produced in the production of thermal PVDF ultrafiltration membranes, belonging to the technical field of industrial wastewater treatment. Background Art

[0002] Thermal PVDF (polyvinylidene fluoride) ultrafiltration membranes have the characteristics of high strength, high toughness, corrosion resistance, long life, etc., and are the fastest growing membrane separation products for water treatment today. The production methods of thermal PVDF ultrafiltration membranes have also been continuously optimized. For example, Patent 202010689728.5, a polyvinylidene fluoride hollow fiber membrane and its preparation method, provides an improved TIPS (thermally induced phase separation) method for preparing polyvinylidene fluoride hollow fiber membranes. PVDF resin, calcium carbonate and phthalate are mixed, extruded at high temperature and high pressure, stretched and annealed to preliminarily produce hollow fiber ultrafiltration membrane filaments, and then post-treated. First, phthalate is extracted with ethanol, then calcium carbonate is reacted with hydrochloric acid, and finally the thermal PVDF ultrafiltration membrane product is washed out. During the production process of thermal PVDF ultrafiltration membranes, a large amount of organic wastewater containing oil, calcium, suspended solids and COD is generated, which has a greater impact on the environment. At present, there are only patents for treating wastewater produced in the wet process of hollow fiber membranes using dimethylacetamide as a solvent. For example, Patent 201310319712.5, a treatment method for wastewater produced in the production of ultrafiltration membranes, uses "iron-carbon microelectrolysis, Fenton, ultrasonic atmospheric pressure plasma, calcium hydroxide coagulation precipitation, microbubble plasma machine" for treatment and discharges up to the standard; another example is Patent 201710957710.7, a recovery system and treatment method for dimethylacetamide in ultrafiltration membrane production wastewater, which uses a refining tower to recover DMAC (dimethylacetamide) and condensed water. For the wastewater produced in the production of thermal PVDF ultrafiltration membranes, a new treatment device and treatment method need to be designed and developed. Summary of the Invention

[0003] The present invention provides a treatment device and treatment method for wastewater produced in the production of thermal PVDF ultrafiltration membranes. Aiming at the characteristics of high COD, SS and oil content in the wastewater produced in the production of thermal PVDF ultrafiltration membranes, a treatment device and treatment method for wastewater produced in the production of thermal PVDF ultrafiltration membranes are proposed, so that the discharged water meets and exceeds the discharge standard limits of Class A in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants GB18918 - 2002, realizing discharge up to the standard or reuse.

[0004] Technical solution of the present invention: A treatment device for the wastewater from the production of thermal PVDF ultrafiltration membranes, the structure of which includes a pretreatment system, a biochemical treatment system, and an advanced treatment system. Among them, the wastewater from the production of thermal PVDF ultrafiltration membranes is connected to the water inlet of the pretreatment system, and the sludge outlet of the pretreatment system sends out sludge cakes; the water outlet of the pretreatment system is connected to the water inlet of the biochemical treatment system, and the sludge outlet of the biochemical treatment system sends backflow sludge to the backflow sludge inlet of the pretreatment system; the water outlet of the biochemical treatment system is connected to the water inlet of the advanced treatment system, and the backwash water outlet of the advanced treatment system sends the backflow backwash water to the backflow backwash water inlet of the pretreatment system, and the water outlet of the advanced treatment system sends out up-to-standard drainage. The treatment device for the wastewater from the production of thermal PVDF ultrafiltration membranes first uses the pretreatment system to remove part of the COD, SS, and oil; then uses the biochemical treatment system to degrade and remove most of the COD, BOD, SS, NH3-N, TP, and oil; finally uses the advanced treatment system to further reduce the COD in the water. So that the drainage reaches COD ≤ 45mg / L, BOD ≤ 5mg / L, SS ≤ 3mg / L, NH3-N ≤ 2mg / L, TP ≤ 0.3mg / L, oil ≤ 1mg / L, meeting and exceeding the discharge standard limits of Class A in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants GB18918-2002, and achieving up-to-standard discharge.

[0005] A treatment method for the wastewater from the production of thermal PVDF ultrafiltration membranes, comprising the following steps:

[0006] 1) Through the pretreatment system, remove more than 50% of the SS, 80% of the oil, and a small amount of COD and BOD in the wastewater from the production of thermal PVDF ultrafiltration membranes;

[0007] 2) Through the biochemical treatment system, remove more than 75% of the organic pollutants in the effluent from the pretreatment system;

[0008] 3) Through the advanced treatment system, further remove 70% of the COD in the effluent from the biochemical treatment system, so that the drainage meets and exceeds the discharge standard limits of Class A in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants GB18918-2002, and achieve up-to-standard discharge.

[0009] Advantages of the present invention: The treatment device and treatment method for the wastewater from the production of thermal PVDF ultrafiltration membranes of the present invention are aimed at the characteristics of the wastewater from the production of thermal PVDF ultrafiltration membranes containing high COD, SS, and oil. First, use the pretreatment system to remove part of the COD, SS, and oil; then use the biochemical treatment system to degrade and remove most of the COD, BOD, SS, NH3-N, TP, and oil; finally use the advanced treatment system to further reduce the COD in the water. So that the drainage meets and exceeds the discharge standard limits of Class A in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants GB18918-2002, and achieve up-to-standard discharge or reuse. Description of the Drawings

[0010] Appended Figure 1 Schematic structural diagram of the treatment device for the production wastewater of the thermal PVDF ultrafiltration membrane.

[0011] In the appended drawings, WW represents wastewater, DW represents drainage, SC represents sludge cake; PTS represents the pretreatment system, BTS represents the biochemical treatment system, and AWTS represents the advanced treatment system.

[0012] Appended Figure 2 Schematic structural diagram of the pretreatment system of the treatment device for the production wastewater of the thermal PVDF ultrafiltration membrane.

[0013] In the appended drawings, PTS represents the pretreatment system, WW represents wastewater, SC represents sludge cake, PT out represents the effluent of the pretreatment system, BF 11 represents the refluxed sludge, BF 12 represents the refluxed backwash water; SN / BP represents the grille / equalization tank, P 11 represents the lift pump, D 11 represents the flocculant dosing device, DAF represents the air flotation device, ST represents the sludge tank, P 12 represents the screw pump, BPF represents the belt filter press.

[0014] Appended Figure 3 Schematic structural diagram of the biochemical treatment system of the treatment device for the production wastewater of the thermal PVDF ultrafiltration membrane.

[0015] In the appended drawings, BTS represents the biochemical treatment system, PT out represents the effluent of the pretreatment system, BT out represents the effluent of the biochemical treatment system, BF 11 represents the refluxed sludge; HT / UASB represents the hydrolysis tank / UASB tank, D 21 represents the coagulant and flocculant dosing device, RT / ST represents the reaction tank / sedimentation tank, OT represents the aeration tank, B 21 represents the aeration blower, MBR represents the membrane bioreactor, B 22 represents the MBR purge blower, P 21 represents the MBR suction pump, MT represents the intermediate water tank, P 22 represents the MBR backwash pump.

[0016] Appended Figure 4 Schematic structural diagram of the advanced treatment system of the treatment device for the production wastewater of the thermal PVDF ultrafiltration membrane.

[0017] In the appended drawings, AWTS represents the advanced treatment system, BT out represents the effluent of the biochemical treatment system, DW represents drainage, BF 12 represents the refluxed backwash water; P 31Denote the booster pump, COT denote the catalytic oxidation tower, O3G denote the ozone generator, GACF denote the activated carbon filter, CT denote the clean water tank, P 32 Denote the GACF backwash pump.

[0018] Appendix Figure 5 Process flow diagram of the treatment of the production wastewater of the thermal PVDF ultrafiltration membrane. Specific implementation manners

[0019] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings

[0020] Refer to the appendix Figure 1 , for the treatment device of the production wastewater of the thermal PVDF ultrafiltration membrane, its structure includes a pretreatment system PTS, a biochemical treatment system BTS, and an advanced treatment system AWTS. Among them, the production wastewater WW of the thermal PVDF ultrafiltration membrane is connected to the water inlet of the pretreatment system PTS, and the sludge outlet of the pretreatment system PTS sends out the sludge cake SC; the water outlet of the pretreatment system PTS is connected to the water inlet of the biochemical treatment system BTS, and the sludge outlet of the biochemical treatment system BTS sends out the return sludge (BF 11 ) to the return sludge inlet of the pretreatment system PTS; the water outlet of the biochemical treatment system BTS is connected to the water inlet of the advanced treatment system AWTS, and the backwash water outlet of the advanced treatment system AWTS sends the return backwash water (BF 12 ) to the return backwash water inlet of the pretreatment system PTS, and the water outlet of the advanced treatment system AWTS sends out the up-to-standard drainage DW. The treatment device of the production wastewater of the thermal PVDF ultrafiltration membrane first uses the pretreatment system to remove part of the COD, SS and oils; then uses the biochemical treatment system to degrade and remove most of the COD, BOD, SS, NH3-N, TP and oils; finally uses the advanced treatment system to further reduce the COD in the water. So that the drainage reaches COD≤45mg / L, BOD≤5mg / L, SS≤3mg / L, NH3-N≤2mg / L, TP≤0.3mg / L, oils≤1mg / L, meeting and exceeding the discharge standard limits of Class A in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants GB18918-2002, realizing up-to-standard discharge.

[0021] Refer to the appendix Figure 2 , for the pretreatment system PTS, its structure includes a grille / equalization tank SN / BP, a lift pump P 11 , a flocculant dosing device D 11 , a flotation device DAF, a sludge tank ST, a screw pump P 12 , a belt filter press BPF. Among them, the production wastewater WW of the thermal PVDF ultrafiltration membrane is connected to the water inlet of the grille / equalization tank SN / BP, and the return backwash water BF 12Inlet for the reflux backwash water connected to the grille / equalization tank SN / BP; the outlet of the grille / equalization tank SN / BP is connected to the lift pump P 11 Connected to the inlet of the dissolved air flotation unit DAF, and the chemical outlet of the flocculant dosing device D 11 is also connected to the inlet of the dissolved air flotation unit DAF. The outlet of the dissolved air flotation unit DAF sends out the pretreated system effluent PTout; the sludge discharge port of the dissolved air flotation unit DAF is connected to the 1# sludge inlet of the sludge tank ST, and the reflux sludge BF 11 is connected to the 2# sludge inlet of the sludge tank ST; the sludge outlet of the sludge tank ST is connected to the inlet of the belt filter press BPF through the screw pump P 12 The outlet of the belt filter press BPF sends out the sludge cake SC, and the filtrate outlet of the belt filter press BPF is connected to the reflux filtrate inlet of the grille / equalization tank SN / BP. Through the pretreatment system, specifically by adding flocculants and coagulant aids, the COD of the thermoplastic PVDF ultrafiltration membrane production wastewater is reduced from 3000 - 7000 mg / L to 2700 - 6300 mg / L by the dissolved air flotation unit, with a removal rate of 10%, the BOD is reduced from 600 - 1400 mg / L to 570 - 1330 mg / L, with a removal rate of 5%, the SS is reduced from 50 - 200 mg / L to 25 - 50 mg / L, with a removal rate of 50 - 75%, and the oil is reduced from 20 - 120 mg / L to 4 - 24 mg / L, with a removal rate of 80%.

[0022] Refer to the appendix Figure 3 , the biochemical treatment system BTS, whose structure includes a hydrolysis tank / UASB tank HT / UASB, a coagulant and coagulant aid dosing device D 21 , a reaction tank / sedimentation tank RT / ST, an aeration tank OT, an aeration blower B 21 , a membrane bioreactor MBR, an MBR purging blower B 22 , an MBR suction pump P 21 , an intermediate water tank MT, an MBR backwash pump P 22 . The pretreated system effluent PTout is connected to the inlet of the hydrolysis tank / UASB tank HT / UASB, and the outlet of the hydrolysis tank / UASB tank HT / UASB is connected to the inlet of the reaction tank / sedimentation tank RT / ST. The chemical outlet of the coagulant and coagulant aid dosing device D 21 is also connected to the inlet of the reaction tank / sedimentation tank RT / ST. The sludge outlet of the reaction tank / sedimentation tank RT / ST sends out the reflux sludge BF 11 ; the outlet of the reaction tank / sedimentation tank RT / ST is connected to the inlet of the aeration tank OT, and the air outlet of the aeration blower B 21 is connected to the air inlet of the aeration tank OT; the outlet of the aeration tank OT is connected to the inlet of the membrane bioreactor MBR, and the MBR purging blower B 22The air outlet is connected to the air inlet of the membrane bioreactor MBR; the water outlet of the membrane bioreactor MBR is connected to the water inlet of the intermediate tank MT through the MBR suction pump P 21 and is connected to the water inlet of the intermediate tank MT. The 1# water outlet of the intermediate tank MT sends out the effluent BTout of the biochemical treatment system. The 2# water outlet of the intermediate tank MT is connected to the backwash water inlet of the membrane bioreactor MBR through the MBR backwash pump P 22 Through the biochemical treatment system, specifically, the hydrolytic acidification and anaerobic biological treatment of the pretreated effluent are carried out in the hydrolysis tank / UASB tank. By adding coagulants and flocculation aids, flocculation precipitation is carried out in the reaction tank / sedimentation tank. Then, aerobic biological treatment and efficient separation of mud and water are carried out using the aerobic tank and the membrane bioreactor, greatly reducing the organic pollutants in the water. Thus, the COD of the pretreated effluent is reduced from 2700 - 6300 mg / L to ≤150 mg / L, with a removal rate of ≥94%; the BOD is reduced from 570 - 1330 mg / L to ≤5 mg / L, with a removal rate of ≥99%; the SS is reduced from 25 - 50 mg / L to ≤5 mg / L, with a removal rate of ≥80%; the NH3-N is reduced from 10 - 20 mg / L to ≤2 mg / L, with a removal rate of ≥80%; the TP is reduced from 0.5 - 2 mg / L to ≤0.3 mg / L, with a removal rate of ≥40%; the oil is reduced from 4 - 24 mg / L to ≤1 mg / L, with a removal rate of ≥75%.

[0023] Control appendix Figure 4 and the advanced treatment system AWTS, whose structure includes a booster pump P 31 , a catalytic oxidation tower COT, an ozone generator O3G, an activated carbon filter GACF, a clear water tank CT, and a GACF backwash pump P 32 . The effluent BTout of the biochemical treatment system is connected to the water inlet of the catalytic oxidation tower COT through the booster pump P 31 . The air outlet of the ozone generator O3G is connected to the air inlet of the catalytic oxidation tower COT; the water outlet of the catalytic oxidation tower COT is connected to the water inlet of the activated carbon filter GACF, the water outlet of the activated carbon filter GACF is connected to the water inlet of the clear water tank CT, and the 1# water outlet of the clear water tank CT sends out the drainage DW; the 2# water outlet of the clear water tank CT is connected to the backwash water inlet of the activated carbon filter GACF through the GACF backwash pump P 32 and the backwash water drain outlet of the activated carbon filter GACF sends out the reflux backwash water BF 12Through the advanced treatment system, specifically by using a catalytic oxidation tower to conduct catalytic oxidation on the effluent from biochemical treatment and then using an activated carbon filter for adsorption, the COD in the water is further reduced from 150 mg / L to ≤45 mg / L, with a removal rate of ≥70%. The final effluent has COD ≤45 mg / L, BOD ≤5 mg / L, SS ≤5 mg / L, NH3-N ≤2 mg / L, TP ≤0.3 mg / L, and oil ≤1 mg / L, meeting and exceeding the discharge standard limits of Class A of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants (GB18918-2002), achieving compliant discharge.

[0024] Control appendix Figure 5 , a treatment method for the production wastewater of a thermal PVDF ultrafiltration membrane, comprising the following steps:

[0025] 1) Through the pretreatment system, more than 50% of the SS in the production wastewater of the thermal PVDF ultrafiltration membrane is removed, 80% of the oil is removed, and a small amount of COD and BOD are removed;

[0026] 2) Through the biochemical treatment system, more than 75% of the organic pollutants in the effluent from the pretreatment system are removed;

[0027] 3) Through the advanced treatment system, the COD in the effluent from the biochemical treatment system is further removed by 70%, enabling the effluent to meet and exceed the discharge standard limits of Class A of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants (GB18918-2002), achieving compliant discharge.

[0028] In step 1), through the pretreatment system, more than 50% of the SS in the production wastewater of the thermal PVDF ultrafiltration membrane is removed, 80% of the oil is removed, and a small amount of COD and BOD are removed. Specifically, by adding a flocculant and a coagulant aid, the COD in the production wastewater of the thermal PVDF ultrafiltration membrane is reduced from 3000 - 7000 mg / L to 2700 - 6300 mg / L, with a removal rate of 10%, the BOD is reduced from 600 - 1400 mg / L to 570 - 1330 mg / L, with a removal rate of 5%, the SS is reduced from 50 - 200 mg / L to 25 - 50 mg / L, with a removal rate of 50 - 75%, and the oil is reduced from 20 - 120 mg / L to 4 - 24 mg / L, with a removal rate of 80%.

[0029] In step 2), more than 75% of the organic pollutants in the effluent from the pretreatment system are removed through a biochemical treatment system. Specifically, a hydrolysis tank / UASB tank is used for hydrolysis acidification and anaerobic biological treatment of the pretreated effluent. By adding a coagulant and a coagulant aid, flocculation precipitation is carried out through a reaction tank / sedimentation tank. Then, an aerobic tank and a membrane bioreactor are used for aerobic biological treatment and efficient separation of mud and water, significantly reducing the organic pollutants in the water. As a result, the COD of the pretreated effluent is reduced from 2700 - 6300 mg / L to ≤150 mg / L, with a removal rate of ≥94%; the BOD is reduced from 570 - 1330 mg / L to ≤5 mg / L, with a removal rate of ≥99%; the SS is reduced from 25 - 50 mg / L to ≤5 mg / L, with a removal rate of ≥80%; the NH3-N is reduced from 10 - 20 mg / L to ≤2 mg / L, with a removal rate of ≥80%; the TP is reduced from 0.5 - 2 mg / L to ≤0.3 mg / L, with a removal rate of ≥40%; and the oil is reduced from 4 - 24 mg / L to ≤1 mg / L, with a removal rate of ≥75%.

[0030] In step 3), through a deep treatment system, 70% of the COD in the effluent from the biochemical treatment system is further removed. Specifically, a catalytic oxidation tower is used for catalytic oxidation of the effluent from the biochemical treatment system, and then an activated carbon filter is used for adsorption, further reducing the COD in the water from 150 mg / L to ≤45 mg / L, with a removal rate of ≥70%. The final effluent has a COD ≤45 mg / L, BOD ≤5 mg / L, SS ≤5 mg / L, NH3-N ≤2 mg / L, TP ≤0.3 mg / L, and oil ≤1 mg / L, making the effluent meet and exceed the discharge standard limits of Class A of the Pollutant Discharge Standard for Municipal Wastewater Treatment Plants (GB18918 - 2002), achieving up-to-standard discharge.

[0031] Example 1

[0032] An enterprise produces 2 million square meters of thermal PVDF ultrafiltration membranes annually. During the production process of thermal PVDF ultrafiltration membranes, some production wastewater is generated, mainly composed of granulation and spinning cooling water, silk washing wastewater, membrane washing wastewater, laboratory drainage, and domestic sewage. This example is for the treatment of the production wastewater of thermal PVDF ultrafiltration membranes, and the effluent reaches the discharge standard limits of Class A of the Pollutant Discharge Standard for Municipal Wastewater Treatment Plants (GB18918 - 2002), achieving up-to-standard discharge. In addition, a small amount of high-salt distillation waste liquid is treated separately.

[0033] 1. Design of influent and effluent water quality and quantity

[0034] The water quality indicators of the production wastewater and effluent of thermal PVDF ultrafiltration membranes are as follows:

[0035]

[0036]

[0037] The water volume of the production wastewater of the thermal PVDF ultrafiltration membrane is 300 T / D.

[0038] 2. Process Flow

[0039] 2.1 Process Flow

[0040] The process flow is shown in the appendix Figure 5 Process flow chart of the production wastewater treatment example of the thermal PVDF ultrafiltration membrane.

[0041] 2.2 Flow Explanation

[0042] The production wastewater of the thermal PVDF ultrafiltration membrane enters the regulation tank through the grille for equalization of water quality and volume, is pumped into the air flotation device by the lift pump, and the oils and SS in the water are removed by adding PAC / PAM (flocculant / coagulant aid). The floating scum of the air flotation enters the sludge tank and is mixed with the sludge discharged from the subsequent sedimentation tank, is pumped into the belt filter press by the screw pump for dehydration, the filtrate returns to the regulation tank, and the sludge cake is transported out. The effluent of the air flotation flows into the hydrolysis tank / UASB tank for hydrolysis acidification and anaerobic biochemical treatment, then flows into the reaction tank / sedimentation tank, and the SS in the water is removed by adding PAC / PAM. The effluent of the sedimentation tank flows into the aeration tank, and aerobic biochemical treatment is carried out by supplying oxygen with the aeration blower. The effluent of the aeration tank flows into the MBR membrane tank for further biochemical treatment and efficient separation. The water treated by biochemical treatment is pumped into the intermediate tank by the MBR suction pump, and the biochemical sludge is effectively isolated in the membrane tank. The MBR membrane is backwashed by the MBR backwash pump and the purge blower to ensure the long-term stable operation of the MBR membrane. The effluent of the intermediate tank is pressurized by the booster pump and pumped into the catalytic oxidation tower, and the ozone generated by the ozone generator is subjected to catalytic oxidation reaction under the action of the catalyst, and then further reduced the organic pollutants in the water by adsorption through the GAC filter. The GAC filter is regularly backwashed by the GAC backwash pump, and the backwash water returns to the regulation tank. The effluent of the GAC filter enters the clear water tank and is discharged up to standard.

[0043] 3. Treatment Effect of Each Unit

[0044] The treatment effects of each unit of the production wastewater of the thermal PVDF ultrafiltration membrane are as follows:

[0045]

[0046]

[0047] 4. Main Design Parameters of the System

[0048] 4.1 Civil Engineering:

[0049]

[0050] 4.2 Main Equipment:

[0051]

[0052]

[0053]

[0054]

Claims

1. Thermal method PVDF ultrafiltration membrane production wastewater treatment device, characterized in that Its structure includes a pretreatment system, a biochemical treatment system, and an advanced treatment system; Among them, the wastewater from the thermal PVDF ultrafiltration membrane production is connected to the inlet of the pretreatment system, and the sludge outlet of the pretreatment system sends out sludge cakes; The outlet of the pretreatment system is connected to the inlet of the biochemical treatment system, and the sludge outlet of the biochemical treatment system sends backflow sludge to the inlet of the backflow sludge of the pretreatment system; the outlet of the biochemical treatment system is connected to the inlet of the advanced treatment system, and the backwash water outlet of the advanced treatment system sends backflow backwash water to the inlet of the backflow backwash water of the pretreatment system, and the outlet of the advanced treatment system sends out up-to-standard drainage; The said biochemical treatment system, its structure includes a hydrolysis tank / UASB tank, a coagulant and flocculant dosing device, a reaction tank / sedimentation tank, an aeration tank, an aeration blower, a membrane bioreactor, an MBR purging blower, an MBR suction pump, an intermediate water tank, and an MBR backwash pump; The effluent of the pretreatment system is connected to the inlet of the hydrolysis tank / UASB tank, the outlet of the hydrolysis tank / UASB tank is connected to the inlet of the reaction tank / sedimentation tank, and the dosing outlet of the coagulant and flocculant dosing device is also connected to the inlet of the reaction tank / sedimentation tank. The sludge outlet of the reaction tank / sedimentation tank sends out backflow sludge; the outlet of the reaction tank / sedimentation tank is connected to the inlet of the aeration tank, and the air outlet of the aeration blower is connected to the air inlet of the aeration tank; the outlet of the aeration tank is connected to the inlet of the membrane bioreactor, and the air outlet of the MBR purging blower is connected to the air inlet of the membrane bioreactor; the outlet of the membrane bioreactor is connected to the inlet of the intermediate water tank through the MBR suction pump. The first outlet of the intermediate water tank sends out the effluent of the biochemical treatment system, and the second outlet of the intermediate water tank is connected to the backwash water inlet of the membrane bioreactor through the MBR backwash pump; it also includes a dosing room, and the said dosing room includes a sodium hypochlorite dosing device, a sodium hydroxide dosing device, and a hydrochloric acid dosing device; The said pretreatment system includes a grille / regulation tank, a lift pump, a flocculant dosing device, a flotation device, a sludge tank, a screw pump, and a belt filter press; Among them, the wastewater from the thermal PVDF ultrafiltration membrane production is connected to the inlet of the grille / regulation tank, and the backwash water is connected to the inlet of the backwash water of the grille / regulation tank; the outlet of the grille / regulation tank is connected to the inlet of the flotation device through the lift pump, and the dosing outlet of the flocculant dosing device is also connected to the inlet of the flotation device. The outlet of the flotation device sends out the effluent of the pretreatment system; the slag discharge port of the flotation device is connected to the first sludge inlet of the sludge tank, and the backflow sludge is connected to the second sludge inlet of the sludge tank; the sludge outlet of the sludge tank is connected to the inlet of the belt filter press through the screw pump, the sludge outlet of the belt filter press sends out sludge cakes, and the filtrate outlet of the belt filter press is connected to the inlet of the backflow filtrate of the grille / regulation tank; The advanced treatment system has a structure including a booster pump, a catalytic oxidation tower, an ozone generator, an activated carbon filter, a clean water tank, and a backwash pump. The effluent from the biochemical treatment system is connected to the inlet of the catalytic oxidation tower through the booster pump, and the gas outlet of the ozone generator is connected to the gas inlet of the catalytic oxidation tower. The outlet of the catalytic oxidation tower is connected to the inlet of the activated carbon filter, the outlet of the activated carbon filter is connected to the inlet of the clean water tank, and the first outlet of the clean water tank discharges water. The second outlet of the clean water tank is connected to the backwash water inlet of the activated carbon filter through the backwash pump, and the backwash water drain outlet of the activated carbon filter discharges the reflux backwash water.

2. The treatment method of the thermal PVDF ultrafiltration membrane production wastewater treatment device according to claim 1, characterized in that It includes the following steps: 1) Pretreatment system treatment to remove more than 50% of SS, 80% of oils, and a small amount of COD and BOD from the wastewater produced in the thermal method PVDF ultrafiltration membrane production. 2) Biochemical treatment system treatment to remove more than 75% of the organic pollutants in the effluent from the pretreatment system. 3) Advanced treatment system treatment to further remove 70% of the COD in the effluent from the biochemical treatment system, so that the discharged water meets the discharge standard of Class A of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants (GB18918-2002), achieving up-to-standard discharge.

3. The treatment method of the thermal PVDF ultrafiltration membrane production wastewater treatment device according to claim 2, characterized in that For the treatment in step 1) by the pretreatment system, specifically, by adding a flocculant and a coagulant aid, using a flotation device to reduce the COD in the wastewater produced in the thermal method PVDF ultrafiltration membrane production from 3000 - 7000 mg / L to 2700 - 6300 mg / L, with a removal rate of 10%, the BOD from 600 - 1400 mg / L to 570 - 1330 mg / L, with a removal rate of 5%, the SS from 50 - 200 mg / L to 25 - 50 mg / L, with a removal rate of 50 - 75%, and the oils from 20 - 120 mg / L to 4 - 24 mg / L, with a removal rate of 80%.

4. The treatment method of the thermal PVDF ultrafiltration membrane production wastewater treatment device according to claim 2, characterized in that For the treatment in step 2) by the biochemical treatment system, it removes more than 75% of the organic pollutants in the effluent from the pretreatment system. Specifically, the hydrolysis tank / UASB tank is used for hydrolysis acidification and anaerobic biological treatment of the pretreatment effluent. By adding a coagulant and a coagulant aid, flocculation precipitation is carried out through the reaction tank / sedimentation tank, and then an aerobic tank and a membrane bioreactor are used for aerobic biological treatment and efficient separation of mud and water, greatly reducing the organic pollutants in the water. Reduce the COD in the pretreatment effluent from 2700 - 6300 mg / L to ≤150 mg / L, with a removal rate of ≥94%, the BOD from 570 - 1330 mg / L to ≤5 mg / L, with a removal rate of ≥99%, the SS from 25 - 50 mg / L to ≤5 mg / L, with a removal rate of ≥80%, the NH3-N from 10 - 20 mg / L to ≤2 mg / L, with a removal rate of ≥80%, the TP from 0.5 - 2 mg / L to ≤0.3 mg / L, with a removal rate of ≥40%, and the oils from 4 - 24 mg / L to ≤1 mg / L, with a removal rate of ≥75%.

5. The treatment method of the thermal method PVDF ultrafiltration membrane production wastewater treatment device according to claim 2, characterized in that In step 3), the advanced treatment system is used for further treatment to remove 70% of the COD in the effluent from the biochemical treatment system. Specifically, the catalytic oxidation tower is used to conduct catalytic oxidation on the effluent from the biochemical treatment, and then the activated carbon filter is used for adsorption to further reduce the COD in the water from 150 mg / L to ≤45 mg / L, with a removal rate of ≥70%. The COD of the final drainage is ≤45 mg / L, BOD is ≤5 mg / L, SS is ≤5 mg / L, NH3-N is ≤2 mg / L, TP is ≤0.3 mg / L, and oil is ≤1 mg / L, enabling the drainage to meet the discharge standard of Class A of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants (GB18918-2002), thus achieving up-to-standard discharge.

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