Polyimide production wastewater recovery treatment device

Abstract

The utility model discloses a device for recycling and treating polyimide production wastewater. The device comprises a deionized water preparation unit, a Fenton reactor and a biochemical treatment integrated unit, the deionized water preparation unit is used for preparing and outputting deionized water to a polyimide production process as washing liquid by inputting tap water, wastewater generated in polyimide production is conveyed to the Fenton reactor through a pipeline, and high-salt-content water output by the deionized water preparation unit is also conveyed to the Fenton reactor through a pipeline. The Fenton reactor is connected with the biochemical treatment integrated unit through a pipeline; the biochemical treatment integrated unit comprises an A / A / O process treatment unit and an MBR membrane-bioreactor, the wastewater treated by the Fenton reactor is sequentially input into the A / A / O process treatment unit and the MBR membrane-bioreactor for treatment, and then qualified wastewater and redundant sludge are discharged. The device not only solves the problem of wastewater discharge, but also can fully improve the utilization rate of deionized water (pure water), reduce wastewater discharge and reduce waste of water resources.

Description

TECHNICAL FIELD

[0001] The utility model relates to wastewater recovery technical field especially relates to a kind of polyimide production wastewater recovery treatment device. BACKGROUND

[0002] Polyimide fiber wet spinning production process can produce wastewater, including polyamide acid solution in jet coagulation forming polyamide acid nascent fiber needs to be washed immediately, to remove the polymer solvent and organic, inorganic impurities etc. on the surface of fiber, wastewater will be produced after washing;Preparation of deionized water (mainly washing liquid), mainly using tap water through the method of RO reverse osmosis preparation, after preparation, part produces deionized water, part produces wastewater with high salt content;In the coagulation bath link, coagulation liquid is composed of solvent and deionized water, spinning dope stream enters coagulation bath, in double diffusion process, the solvent concentration in coagulation liquid is higher and higher, and high concentration coagulation liquid will cause economic loss and water environmental pollution if it is discharged, so solvent in coagulation liquid needs to be recovered.According to the difference between water and solvent boiling point, the recovery process mostly uses heating distillation method to recover solvent, and in the recovery process, water vapor condensation inevitably takes away part of solvent, causing COD to be too high.Therefore, the wastewater produced in the production process of polyimide fiber mainly contains NMP solvent, and this wastewater contains a large amount of organic pollutants, which will cause irreversible damage to human beings and the natural environment if directly discharged into the environment.Because NMP wastewater contains nitrogen heterocyclic organic matter, it has the characteristics of high concentration of COD (chemical oxygen demand), total nitrogen, etc., although its biodegradability exists, the degradation rate is slow, and it has certain biological toxicity.In addition, the carbon-nitrogen ratio of wastewater is unbalanced, and a large amount of carbon source is consumed for denitrification, increasing the treatment cost.Currently, the existing technology mainly uses extraction distillation and distillation recovery for the NMP-containing wastewater produced in the production process of polyimide fiber, which consumes a large amount of steam, does not meet the environmental protection, energy saving and emission reduction policy, and the temperature is high during distillation, which is easy to cause high-temperature polymerization of NMP. SUMMARY

[0003] Therefore, the utility model provides a kind of polyimide production wastewater recovery treatment device, solves wastewater discharge problem, can more fully improve pure water utilization, reduce wastewater discharge, reduce production cost.

[0004] The utility model discloses a technical scheme, a kind of polyimide production wastewater recovery treatment device, including deionized water preparation unit, fenton reactor, biochemical treatment integrated unit. The deionized water preparation unit is prepared by input tap water and exports deionized water to polyimide production process as washing liquid, wastewater generated by polyimide production is transported to fenton reactor by pipeline, and the high salt content water exported by deionized water preparation unit is also transported to fenton reactor by pipeline. The fenton reactor is connected with the pipeline of biochemical treatment integrated unit, and the biochemical treatment integrated unit includes A / A / O process treatment unit, MBR membrane-bioreactor, wastewater treated by fenton reactor is sequentially input to A / A / O process treatment unit, MBR membrane-bioreactor, then discharge qualified wastewater and excess sludge.

[0005] Preferably, the deionized water preparation unit includes quartz sand filter tank, activated carbon filter tank connected with the pipeline of quartz sand filter tank, first RO membrane filter connected with the pipeline of activated carbon filter tank, the tap water is input to quartz sand filter tank by pipeline, and is filtered in quartz sand filter tank, activated carbon filter tank, first RO membrane filter in sequence, the first RO membrane filter is equipped with first output port and first waste outlet, and the first output port exports deionized water, and the first waste outlet exports high-salt-content wastewater.

[0006] Preferably, the MBR membrane-bioreactor adopts MBR hollow fiber membrane.

[0007] Preferably, the MBR membrane-bioreactor is equipped with sludge backflow pump, and the sludge backflow pump is connected to the inner bottom of MBR membrane-bioreactor by pipeline, and the sludge and wastewater mixture is pumped back to the anaerobic tank of A / A / O process treatment unit by pipeline, or is pumped out and discharged.

[0008] Further, the sludge backflow pump extracts the sludge and wastewater mixture in the MBR membrane-bioreactor, and the discharge pipeline connected with the sludge and wastewater mixture is connected with a filter press, and the sludge and wastewater mixture is dewatered by the filter press.

[0009] Preferably, the outer side of the MBR membrane-bioreactor is provided with a disinfection tank, the wastewater treated by the MBR membrane-bioreactor is discharged to the disinfection tank, the disinfection tank is provided with a plurality of ultraviolet lamps, the wastewater is irradiated by ultraviolet rays, and the disinfection tank is provided with a wastewater discharge port.

[0010] Preferably, the wastewater discharge port of the disinfection tank is provided with a branch pipeline, the front end of the branch pipeline is connected with a second RO membrane filter, the second RO membrane filter is provided with a second output port and a second waste outlet, the second output port is connected to the quartz sand filter tank by pipeline, and the second waste outlet is connected to the fenton reactor by pipeline.

[0011] The polyimide production wastewater recycling device has the beneficial effects that the recycling device is used for recycling and treating wastewater generated in the preparation of polyimide fibers, and the wastewater includes the following: the main washing liquid, deionized water, wastewater with high salt content generated in the preparation of deionized water, and wastewater containing NMP solvent, organic and inorganic impurities and broken fibers generated in the washing process and coagulation bath process of the polyimide fiber preparation process. The wastewater is transported to the Fenton reactor and the biochemical treatment integrated unit through pipelines for wastewater treatment. The NMP is oxidized and decomposed into small molecules by the Fenton method, and the biodegradability is improved. Under the aerobic condition, the NH3 and ammonium salt in the wastewater are oxidized into NO2-N and NO3-N by nitrifying bacteria through the A / A / O process. Subsequently, under the anoxic condition, the substances are reduced into N2 through the denitrification reaction, so that the nitrogen removal is realized. After the A / A / O process treatment, the ammonia nitrogen concentration of the wastewater is significantly reduced, and the discharge standard is reached. The wastewater meeting the discharge standard is subjected to two-stage RO reverse osmosis membranes to remove the dissolved salts, colloids, microorganisms and organic matters in the water, and qualified deionized water is obtained. The device not only solves the wastewater discharge problem, but also can fully improve the utilization rate of deionized water (pure water), reduce wastewater discharge and water resource waste. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 It is a structural schematic view of the utility model.

[0013] Reference signs:

[0014] 1, deionized water preparation unit; 40, A / A / O process treatment unit;

[0015] 2, Fenton reactor; 50, MBR membrane-biological reactor;

[0016] 3, biochemical treatment integrated unit; 60, sludge backflow pump;

[0017] 10, quartz sand filter tank; 70, disinfection tank;

[0018] 20, activated carbon filter tank; 80, second RO membrane filter;

[0019] 30, first RO membrane filter; 801, second output port;

[0020] 301, first output port; 802, second waste discharge port.

[0021] 302, first waste discharge port; DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of the present disclosure.

[0023] Please refer to Figure 1 A polyimide production wastewater recovery treatment device is provided, which comprises a deionized water preparation unit 1, a Fenton reactor 2, and a biochemical treatment integrated unit 3. The deionized water preparation unit 1 prepares output deionized water from input tap water as a washing liquid for the polyimide production process. The wastewater generated by the polyimide production is transported to the Fenton reactor 2 through a pipeline, and the high-salt-content water output by the deionized water preparation unit 1 is also transported to the Fenton reactor 2 through a pipeline. The Fenton reactor 2 is connected to the biochemical treatment integrated unit 3 through a pipeline. The biochemical treatment integrated unit 3 comprises an A / A / O process treatment unit 40 and an MBR membrane-bioreactor 50. The wastewater treated by the Fenton reactor 2 is sequentially input to the A / A / O process treatment unit 40 and the MBR membrane-bioreactor 50 for treatment, and then discharged as qualified wastewater and excess sludge.

[0024] Among them, A / A / O process, also known as anaerobic-anoxic-aerobic process, is a commonly used technology in wastewater treatment. The process consists of three main parts: anaerobic, anoxic and aerobic sections, corresponding to A, A and O in A / A / O.

[0025] Anaerobic section: raw wastewater and phosphorus-containing return sludge discharged from the sedimentation tank are simultaneously introduced into the anaerobic reactor. Its main function is to release phosphorus, and part of the organic matter is ammoniated.

[0026] Anoxic section: nitrate nitrogen is sent from the aerobic reactor to the anoxic reactor through internal circulation. The main function is denitrification. The anoxic section removes nitrate nitrogen through denitrification, and uses organic carbon for denitrification reaction to convert combined nitrogen into free nitrogen.

[0027] Aerobic section: the aeration tank performs aerobic reaction, and the main functions include removal of BOD, nitrification and absorption of phosphorus, etc. The aerobic section provides oxygen through aeration to perform organic oxidation and ammonia nitrogen nitrification reaction.

[0028] As a preferred scheme of the deionized water preparation unit 1, the deionized water preparation unit 1 comprises a quartz sand filter tank 10, an activated carbon filter tank 20 connected to the quartz sand filter tank 10 by a pipeline, and a first RO membrane filter 30 connected to the activated carbon filter tank 20 by a pipeline. Tap water is input into the quartz sand filter tank 10 through a pipeline and is filtered in sequence through the quartz sand filter tank 10, the activated carbon filter tank 20, and the first RO membrane filter 30. The first RO membrane filter 30 is provided with a first output port 301 and a first waste discharge port 302. The first output port 301 outputs deionized water, and the first waste discharge port 302 outputs high-salt-content wastewater.

[0029] In a preferred embodiment, the MBR membrane-bioreactor 50 adopts MBR hollow fiber membranes. The MBR membrane-bioreactor 50 is provided with a sludge backflow pump 60 connected to the inner bottom of the MBR membrane-bioreactor 50 by a pipeline to draw back the sludge and wastewater mixture into the anaerobic tank of the A / A / O process treatment unit 40 or to discharge it.

[0030] In another preferred embodiment, the MBR membrane-bioreactor 50 is provided with a disinfection tank 70 on the outside. The wastewater treated by the MBR membrane-bioreactor 50 is discharged into the disinfection tank 70. The disinfection tank 70 is provided with a plurality of ultraviolet lamps to irradiate the wastewater with ultraviolet light. The disinfection tank 70 is provided with a wastewater discharge port.

[0031] Further, the wastewater discharge port of the disinfection tank 70 is provided with a branch pipeline. A second RO membrane filter 80 is connected to the front end of the branch pipeline. The second RO membrane filter 80 is provided with a second output port 801 and a second waste discharge port 802. The second output port 801 is connected to the quartz sand filter tank 10 by a pipeline, and the second waste discharge port 802 is connected to the Fenton reactor 2 by a pipeline.

[0032] The working principle process of the wastewater recovery treatment device of the scheme is as follows: the wastewater generated in the polyimide fiber production process is collected and filtered and then enters the Fenton reactor 2, the NMP is oxidized and decomposed into small molecules by the oxidizing agent, and the biodegradability is improved, at this time the COD removal rate of the Fenton reactor 2 effluent is 50%-70%, the Fenton reactor 2 effluent PH value is adjusted to 6-9 and then enters the anaerobic tank of the A / A / O process treatment unit 40, the wastewater with high COD concentration is subjected to anaerobic digestion, the COD removal rate is improved, the high molecular weight organic matter is converted into low molecular weight organic matter which is easy to be degraded, and the BOD / COD ratio is improved. Then the wastewater after anaerobic treatment enters the anoxic tank, the nitrate nitrogen is converted into nitrogen by denitrification, and the TN content is reduced. Then the anoxic wastewater enters the aeration tank through the bottom, the organic nitrogen in the wastewater is converted into nitrate nitrogen by the nitrification of the aeration tank, and then the nitrate nitrogen is converted into nitrogen by the denitrification of the anoxic tank, and then enters the MBR membrane-biological reactor 50, the mud and water are separated by the hollow fiber membrane of the MBR, and the microorganisms in the reaction tank are intercepted by the membrane, so that the concentration of the activated sludge in the tank is greatly increased, and the pollutants are maximally degraded, and the excess activated sludge is returned to the anaerobic tank or transported out by the pressure filtration by the sludge return pump 60. The MBR effluent is disinfected by ultraviolet rays and then discharged or recycled, at this time the water quality indexes all meet the first level A discharge standard. For recycling, the water after biochemical treatment and disinfection enters the second RO membrane filter 80, the quartz sand filter tank 10, the activated carbon filter tank 20 and the first RO membrane filter 30, removes the dissolved salts, colloids, microorganisms and organic matter in the water, and obtains qualified deionized water, thereby reducing the waste of water resources. The wastewater is operated according to the process as follows:

[0033] Detection item Before treatment After treatment cod (mg / L) 1953 12 NH4-N (mg / L) 28 2 TN (mg / L) 44 7 TP 7.06 6.9

[0034] The above has described various embodiments of the present disclosure, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles, practical applications or improvements to the technology in the market of the embodiments, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A polyimide production wastewater recovery treatment device characterized by comprising: a polyimide production wastewater treatment device; and a polyimide production wastewater recovery device. The application relates to a water treatment system, which comprises a deionized water preparation unit, a Fenton reactor and a biochemical treatment integrated unit. The deionized water preparation unit prepares output deionized water from input tap water as a washing liquid for a polyimide production process, and the wastewater generated by the polyimide production process is transported to the Fenton reactor through a pipeline, and the high-salt-content water output by the deionized water preparation unit is also transported to the Fenton reactor through a pipeline. The Fenton reactor is connected to the biochemical treatment integrated unit through a pipeline. The biochemical treatment integrated unit comprises an A / A / O process treatment unit and an MBR membrane-bioreactor, the wastewater treated by the Fenton reactor is sequentially input into the A / A / O process treatment unit and the MBR membrane-bioreactor for treatment, and then qualified wastewater and excess sludge are discharged.

2. The polyimide production wastewater recovery treatment device according to claim 1, characterized by, The deionized water preparation unit comprises a quartz sand filter tank, an activated carbon filter tank connected to the quartz sand filter tank through a pipeline and a first RO membrane filter connected to the activated carbon filter tank through a pipeline, the tap water is input into the quartz sand filter tank and filtered through the quartz sand filter tank, the activated carbon filter tank and the first RO membrane filter in sequence, the first RO membrane filter is provided with a first output port and a first waste discharge port, the first output port outputs deionized water, and the first waste discharge port outputs high-salt-content wastewater.

3. The polyimide production wastewater recovery treatment device according to claim 1, characterized by The MBR membrane-bioreactor adopts an MBR hollow fiber membrane.

4. The polyimide production wastewater recovery treatment device according to claim 1, characterized by The MBR membrane-bioreactor is provided with a sludge backflow pump, which is connected to the inner bottom of the MBR membrane-bioreactor through a pipeline, and the sludge and wastewater mixture is pumped back to the anaerobic tank of the A / A / O process treatment unit through a pipeline or is pumped out for discharge.

5. The polyimide production wastewater recovery treatment device according to claim 4, characterized by The sludge and wastewater mixture pumping pipeline connected to the sludge backflow pump is provided with a filter press, which is used for dewatering treatment of the sludge and wastewater mixture.

6. The polyimide production wastewater recovery treatment device according to claim 2, characterized by The MBR membrane-bioreactor is provided with a disinfection tank outside, the wastewater treated by the MBR membrane-bioreactor is discharged into the disinfection tank, the disinfection tank is provided with a plurality of ultraviolet lamps for ultraviolet irradiation of the wastewater, and the disinfection tank is provided with a wastewater discharge port.

7. The polyimide production wastewater recovery treatment device according to claim 6, characterized by The wastewater discharge port of the disinfection tank is provided with a branch pipeline, the front end of the branch pipeline is connected to a second RO membrane filter, the second RO membrane filter is provided with a second output port and a second waste discharge port, the second output port is connected to the quartz sand filter tank through a pipeline, and the second waste discharge port is connected to the Fenton reactor through a pipeline.

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