CN214936821U

CN214936821U - Coal chemical wastewater treatment system

Info

Publication number: CN214936821U
Application number: CN202120391334.1U
Authority: CN
Inventors: 俞德仁; 柏明锁; 李元友; 于莹莹
Original assignee: Beijing Zhonglixinda Environmental Technology Co ltd
Current assignee: Beijing Zhonglixinda Environmental Technology Co ltd
Priority date: 2021-02-19
Filing date: 2021-02-19
Publication date: 2021-11-30
Anticipated expiration: 2031-02-19

Abstract

A coal chemical wastewater treatment system, which comprises a pretreatment device, a CWAO catalytic wet oxidation device and an MVR evaporation device, NF nanofiltration integrated equipment, a coagulating sedimentation device, a biochemical treatment device and RO integrated equipment, the pretreatment device is communicated with a CWAO catalytic wet oxidation device, the CWAO catalytic wet oxidation device is communicated with an MVR evaporation plant, the MVR evaporation plant is connected with a mother liquor conveying pipeline and a condensed water conveying pipeline, the mother liquor conveying pipeline is communicated with the NF nanofiltration integrated equipment, the condensed water conveying pipeline is communicated with the biochemical treatment device, the NF nanofiltration integrated equipment is connected with a permeate liquid conveying pipeline and a concentrated liquid conveying pipeline, the permeate liquid conveying pipeline is communicated with the RO integrated equipment, the concentrated liquid conveying pipeline is communicated with the coagulating sedimentation device, the coagulating sedimentation device comprises a sedimentation device, the sedimentation device is communicated with the biochemical treatment device, and the RO integrated equipment is connected with a sodium hypochlorite preparation device. The grading treatment and the gradient utilization of the wastewater are realized, and the ecological environment protection is embodied.

Description

Coal chemical wastewater treatment system

Technical Field

The utility model belongs to the technical field of sewage treatment, concretely relates to coal chemical wastewater treatment system.

Background

The high-concentration wastewater treatment in the existing coal chemical industry is always concerned, and a large amount of high-concentration wastewater generated in the production process of the coal chemical industry is mainly formed in a coal gas washing (coal gasification unit), a condensation (coal gasification unit) and a purification process (purification unit), wherein the washing water and condensed water produced by the coal gasification unit are used as main components, the high-concentration wastewater mainly comprises acidic organic wastewater and other high-concentration wastewater, particularly high-salt wastewater, the wastewater is high in water temperature, multiple in suspended matters, high in salt content, high in hardness and high in ammonia nitrogen, contains a certain amount of organic matters such as glycerol and medium and low carbon chains, the components are complex, the toxicity to biochemical bacteria is strong, and the wastewater treatment technology difficulty is far higher than that of common wastewater treatment due to the strong inhibition effect on the growth of microorganisms. The high-salt wastewater currently researched and commonly used comprises an evaporation method, an electrolysis method, a membrane separation method, an incineration method, an iron-carbon micro-electrolysis + coagulating sedimentation, fenton oxidation + coagulating sedimentation, an ozone oxidation treatment method and the like, wherein the high-salt wastewater refers to wastewater with the mass fraction of total salts calculated by NaCl content being more than or equal to 1%, and the wastewater contains organic pollutants, a large amount of soluble inorganic salt ions such as sodium, chlorine, calcium, magnesium, sulfate radicals and the like, and even radioactive substances. Therefore, how to effectively treat the high-salinity wastewater becomes the key point of the research on the wastewater treatment of the coal chemical industry, and is also a difficult point.

The published chinese patent documents do not contain any information on the related art of the treatment of the landfill leachate, and CN112250258A (a treatment system for mixed wastewater in coal chemical industry), CN111777291A (a treatment system for wastewater in coal chemical industry), CN211198899U (a treatment apparatus for wastewater in coal chemical industry), CN210215108U (a treatment system for high concentration wastewater in coal chemical industry) and the like are exemplified. Chinese patent document No. CN210656540U discloses a coal chemical wastewater treatment system, which comprises a wet oxidation reactor, a wastewater preconcentration subsystem and a crystallization subsystem, and has the advantages that the coal chemical wastewater can be heated and evaporated in a low-temperature multi-effect evaporator for preconcentration before entering the wet oxidation reactor, so that the amount of the coal chemical wastewater entering the wet oxidation reactor is greatly reduced, the energy consumption of the wet oxidation reactor is reduced, and the wastewater treatment cost of the wet oxidation reaction is significantly reduced; and the high-salinity wastewater subjected to wet oxidation treatment can be evaporated and concentrated to generate saturated wastewater, and the saturated wastewater is crystallized in a centrifugal crystallization device, so that zero emission of pollutants is realized, and the energy consumption of zero emission of wastewater is obviously reduced by reusing heat energy. However, the technical scheme introduced by the technical document still has the following problems: firstly, the difficultly degradable and toxic components in the high-concentration wastewater in the coal chemical industry are effectively destroyed or treated, the treatment effect is not obvious, and particularly, divalent and trivalent ions in a concentrated solution formed by the coal chemical industry wastewater after multiple times of evaporation are not effectively treated; secondly, the process of evaporating and concentrating the high-salt wastewater to generate saturated wastewater and crystallizing the saturated wastewater in a centrifugal crystallization device cannot realize resource utilization of the crystalline salt in the high-salt wastewater, and is not beneficial to environmental protection and production saving.

In view of the above, there is a need for a reasonable improvement of the structure of the existing coal chemical wastewater treatment equipment. The applicant has therefore made an advantageous design, in the context of which the solution to be described below is made.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a thereby be favorable to realizing high-efficient safety processing to hierarchical processing, the step utilization of coal chemical industry waste water, help the thorough zero release of the high strong brine of coal chemical industry waste water and the resource utilization of wherein crystalline salt to embody ecological environmental protection and safe and reliable's coal chemical industry effluent disposal system.

The utility model discloses a task is accomplished like this, a coal chemical industry effluent disposal system, its characterized in that: the device comprises a pretreatment device, a CWAO catalytic wet oxidation device, an MVR evaporation plant, an NF nanofiltration integrated device, a coagulating sedimentation device, a biochemical treatment device and an RO integrated device, wherein a water outlet of the pretreatment device is communicated with a water inlet of the CWAO catalytic wet oxidation device through a pipeline, a water outlet of the CWAO catalytic wet oxidation device is connected with a degradation liquid conveying pipeline which is communicated with a water inlet of the MVR evaporation device, a liquid outlet end of the MVR evaporation device is connected with a mother liquid conveying pipeline and a condensed water conveying pipeline, an outflow end of the mother liquid conveying pipeline is communicated with a water inlet of the NF nanofiltration integrated device, an outflow end of the condensed water conveying pipeline is communicated with the biochemical treatment device, a liquid outlet end of the NF nanofiltration integrated device is connected with a permeate liquid conveying pipeline and a concentrated liquid conveying pipeline, and an outflow end of the permeate liquid conveying pipeline is communicated with a water inlet of the RO integrated device, the outflow end of the concentrated solution conveying pipeline is communicated with a water inlet of the coagulating sedimentation device, the coagulating sedimentation device comprises a sedimentation device, a sewage conveying pipeline is connected to the liquid outlet end of the sedimentation device, the outflow end of the sewage conveying pipeline is communicated with the biochemical treatment device, the concentrated solution outlet end of the RO integrated device is connected with a concentrated solution conveying pipeline, and the other end of the concentrated solution conveying pipeline is connected with a sodium hypochlorite preparation device.

The utility model discloses a specific embodiment, preprocessing device is including grid filter equipment, just heavy pond and equalizing basin, grid filter equipment and rubbish penetrant inlet intercommunication, and install mechanical grid in this grid filter equipment just be provided with a central intake section of thick bamboo in the heavy pond just, this central intake section of thick bamboo passes through the pipeline and is connected with grid filter equipment, just heavy pond export with the access connection of equalizing basin be provided with the equalizing basin elevator pump in the equalizing basin, this equalizing basin elevator pump passes through pipeline and CWAO catalysis wet-type oxidation device intercommunication and can be with the adjusting basin in squeeze into water liquid to CWAO catalysis wet-type oxidation device.

In another specific embodiment of the present invention, the bottom of the sedimentation device of the coagulating sedimentation device is connected with a sludge conveying pipe, the other end of the sludge conveying pipe, i.e. the water outlet end, is connected with a sludge pump, and the sludge pump is communicated with a filter press through a pipeline, and one side of the filter press is connected with a sludge transporting device.

In another specific embodiment of the present invention, the biochemical treatment device comprises an anoxic tank, an aerobic tank, an MBR membrane tank and a clean water tank, the outflow end of the condensed water conveying pipeline and the sewage conveying pipeline enter into the anoxic tank, a water outlet is formed at the upper part of the anoxic tank to be communicated with the aerobic tank, and an aerobic tank water outlet is formed at the upper part of the aerobic tank to be communicated with the MBR membrane tank.

In another specific embodiment of the present invention, a plurality of aeration heads of the aerobic tank are disposed at the bottom of the aerobic tank, and a plurality of aeration heads of the membrane tank are also disposed at the bottom of the MBR membrane tank, and the aeration heads of the aerobic tank and the membrane tank are connected to an air blower disposed outside the biochemical treatment apparatus through a pipeline.

The utility model discloses a still a specific embodiment install the MBR membrane module in the MBR membrane cisterna, and the MBR membrane module has a self priming pump through the pipe connection, and the feed liquor end of this self priming pump communicates with the play liquid end of MBR membrane module, and the play liquid end of this self priming pump passes through the pipeline intercommunication with the clean water basin.

In yet another specific embodiment of the present invention, a reflux pump is further installed at the bottom of the MBR membrane tank, the reflux pump is connected to a reflux pipe, and the outflow end of the reflux pipe enters the anoxic tank.

In a more specific embodiment of the present invention, a clear water liquid conveying pipeline is further connected to the RO integrated device, and an outflow end of the clear water liquid conveying pipeline enters into a clear water tank of the biochemical treatment apparatus.

The technical scheme provided by the utility model the technical effect lie in: firstly, the coal chemical industry wastewater can be efficiently and environmentally treated by arranging a pretreatment device, a CWAO catalytic wet oxidation device, an MVR evaporation device, an NF nanofiltration integrated device, a coagulating sedimentation device, a biochemical treatment device and an RO integrated device, and the purposes of grading treatment and gradient utilization are achieved, and the effective treatment of divalent and trivalent ions in the coal chemical industry wastewater is realized by arranging the NF nanofiltration integrated device and the coagulating sedimentation device; thirdly, a concentrated solution delivery pipe and a sodium hypochlorite preparation device communicated with the concentrated solution delivery pipe are arranged at the concentrated solution outlet end of the RO integrated equipment, so that high-concentration brine in the coal chemical wastewater is efficiently treated and completely zero discharge is realized, the crystallized salt is recycled, and the purposes of energy conservation, environmental protection and resource recycling are achieved.

Drawings

Fig. 1 is an overall structural diagram of an embodiment of the present invention.

FIG. 2 is a schematic process flow diagram of the embodiment of FIG. 1.

In the figure: 1. the system comprises a pretreatment device, 11, a grid filtering device, 111, a mechanical grid, 12, a primary settling tank, 121, a central water inlet cylinder, 13, an adjusting tank and 131, an adjusting tank lifting pump; 2, a CWAO catalytic wet oxidation device, 21, a degradation liquid conveying pipeline; MVR evaporation equipment, 31 mother liquor conveying pipelines, 32 condensed water conveying pipelines; 4, NF nanofiltration integrated equipment, 41, a permeate liquid conveying pipeline and 42, a concentrated liquid conveying pipeline; 5. the system comprises a coagulating sedimentation device, 51, sedimentation equipment, 511, a sludge conveying pipeline, 52, a sewage conveying pipeline, 53, a sludge pump, 54, a filter press and 55, sludge outward transportation equipment; 6. biochemical treatment device, 61 anoxic tank, 62 aerobic tank, 621 aerobic tank aeration head, 63.MBR membrane tank, 631 membrane tank aeration head, 632 MBR membrane module, 633 self-priming pump, 634 reflux pump, 635 reflux pipe, 64 clean water tank, 65 blower; 7, RO integrated equipment, 71, a concentrated solution conveying pipeline, 72, a sodium hypochlorite preparation device, 73, a clear water liquid conveying pipeline.

Detailed Description

In order to make the technical essence and advantages of the present invention more clear, the applicant below describes in detail the embodiments, but the description of the embodiments is not a limitation of the present invention, and any equivalent changes made according to the inventive concept, which are only formal and not essential, should be considered as the technical scope of the present invention.

In the following description, all the concepts related to the directions or orientations of up, down, left, right, front and rear are based on the position state of fig. 1, and thus, should not be interpreted as a specific limitation to the technical solution provided by the present invention.

Referring to fig. 1 and 2, a coal chemical wastewater treatment system is shown, which comprises a pretreatment device 1, a CWAO catalytic wet oxidation device 2, an MVR evaporation plant 3, an NF nanofiltration integrated device 4, a coagulating sedimentation device 5, a biochemical treatment device 6 and an RO integrated device 7, wherein a water outlet of the pretreatment device 1 is communicated with a water inlet of the CWAO catalytic wet oxidation device 2 through a pipeline, a water outlet of the CWAO catalytic wet oxidation device 2 is connected with a degradation liquid conveying pipeline 21, the degradation liquid conveying pipeline 21 is communicated with a water inlet of the MVR evaporation device 3, a liquid outlet end of the MVR evaporation device 3 is connected with a mother liquid conveying pipeline 31 and a condensed water conveying pipeline 32, an outflow end of the mother liquid conveying pipeline 31 is communicated with a water inlet of the NF nanofiltration integrated device 4, and an outflow end of the condensed water conveying pipeline 32 is communicated with the biochemical treatment device 6, the outlet end of the NF nanofiltration integrated equipment 4 is connected with a permeate liquid conveying pipeline 41 and a concentrate liquid conveying pipeline 42, the outlet end of the permeate liquid conveying pipeline 41 is communicated with the water inlet of the RO integrated equipment 7, the outlet end of the concentrate liquid conveying pipeline 42 is communicated with the water inlet of the coagulating sedimentation device 5, the coagulating sedimentation device 5 comprises a sedimentation device 51, the outlet end of the sedimentation device 51 is connected with a sewage conveying pipeline 52, the outlet end of the sewage conveying pipeline 52 is communicated with the biochemical treatment device 6, the concentrate liquid outlet end of the RO integrated equipment 7 is connected with a concentrate liquid conveying pipeline 71, and the other end of the concentrate liquid conveying pipeline 71 is connected with a sodium hypochlorite preparation device 72.

In this embodiment, the pretreatment device 1 includes a grating filter device 11, a primary sedimentation tank 12 and a regulating tank 13, the grating filter device 11 is communicated with the liquid inlet of the waste leachate, and a mechanical grating 111 is installed in the grating filter device 11, the mechanical grating 111 can firstly intercept large pollutants in a suspended or floating state in the waste leachate, wherein the mechanical grating 111 is preferably a 1mm fine grating, and is preferably made of 316SS (molybdenum-containing stainless steel), and the grating has corrosion resistance; a central water inlet cylinder 121 is arranged in the primary sedimentation tank 12, the central water inlet cylinder 121 is connected with the grid filtering device 11 through a pipeline, the outlet of the primary sedimentation tank 12 is connected with the inlet of the adjusting tank 13, an adjusting tank lift pump 131 is arranged in the adjusting tank 13, the adjusting tank lift pump 131 is communicated with the ammonia nitrogen stripping tower 2 through a pipeline, the garbage penetrating fluid filtered by the mechanical grid 111 can be precipitated in the primary sedimentation tank 12 to remove suspended impurities and sludge in the garbage penetrating fluid, and the adjusting tank 13 has the function of adjusting the water quality and water quantity of the garbage penetrating fluid.

In this embodiment, the CWAO catalytic wet oxidation apparatus 2 is a device for treating high-concentration organic wastewater by using a catalytic wet oxidation method, and the catalytic wet oxidation method (CWAO) is an advanced environmental protection technology for treating high-concentration organic wastewater developed in mid-eighties internationally on the basis of the wet oxidation method, and specifically, organic matters and ammonia in wastewater are oxidized and decomposed into harmless substances such as carbon dioxide, water and nitrogen respectively by air and an oxidant under the action of a certain temperature, pressure and a catalyst, thereby achieving the purpose of purification. After being treated by the pretreatment device 1, the coal chemical industry wastewater flows into the CWAO catalytic wet oxidation device 2 to undergo a CWAO catalytic oxidation reaction, so that most organic matters in the coal chemical industry wastewater are removed and formed into degradation liquid, and then the degradation liquid is conveyed into the MVR evaporation equipment 3 through a pipeline to be treated in the next step; for information on the technology related to the catalytic wet oxidation (CWAO), reference is made to the patent document "catalytic wet oxidation reaction tower and method and apparatus for treating high concentration organic wastewater using the same" disclosed in the publication No. CN 104761041B.

In this embodiment, the MVR evaporation apparatus 3 refers to a system that uses an MVR, i.e., a mechanical vapor recompression (mechanical vapor recompression) technology, which uses secondary vapor generated by the evaporation system and energy thereof to increase low-grade vapor into high-grade vapor heat source through mechanical work of a compressor. The MVR evaporation equipment 3 can preferably select a high-efficiency energy-saving MVR evaporator produced by Xishan snow wave chemical equipment factories in the Wuxi city. And the degradation liquid formed after the treatment of the CWAO catalytic wet oxidation device 2 is subjected to evaporation concentration treatment in the MVR evaporation equipment 3, the degradation liquid is separated into condensed water and coal chemical industry mother liquid after the evaporation concentration treatment, the coal chemical industry mother liquid contains a large amount of monovalent ions, divalent ions and more than divalent ions and a large amount of organic matters, the condensed water is conveyed into the biochemical treatment device 6 through the condensed water conveying pipeline 32, and the coal chemical industry mother liquid formed by evaporation is conveyed to the NF nanofiltration integrated equipment 4 through the mother liquid conveying pipeline 31 to be subjected to separation treatment.

Further, the NF nanofiltration integration apparatus 4 includes molecular sieves with specific pore diameters, the molecular sieves with specific pore diameters can separate coal chemical industry mother liquor formed by evaporation treatment, and form permeate and concentrate, through the separation of the special molecular sieves of the NF nanofiltration integration apparatus 4, monovalent ions in the original coal chemical industry mother liquor, such as sodium ions and chloride ions, permeate and flow into the permeate, the permeate is transported into the RO integration apparatus 7 through the permeate transport pipeline 41, and divalent and above-divalent ions, such as calcium ions, magnesium ions and organic matters, are retained in the concentrate, and the concentrate is transported into the coagulation and precipitation device 5 through the concentrate transport pipeline 42 to perform coagulation and precipitation operations.

Furthermore, the bottom of the settling device 51 of the coagulating sedimentation device 5 is connected with a sludge conveying pipeline 511, the other end of the sludge conveying pipeline 511, namely the water outlet end, is connected with a sludge pump 53, the sludge pump 53 is communicated with a filter press 54 through a pipeline, and one side of the filter press 54 is connected with a sludge transporting device 55; the concentrated solution formed by filtering through the NF nanofiltration integrated equipment 4 is subjected to coagulating sedimentation treatment in the coagulating sedimentation device 5 by adjusting the pH value and adding PAC (polyaluminium chloride) and PAM (polyacrylamide) coagulant, so that most of divalent and trivalent ions in the concentrated solution are precipitated, part of organic matters can be removed by precipitation, sewage and sludge are formed after the precipitation operation, the sewage enters the biochemical treatment device 6 through the conveying of the sewage conveying pipeline 52, the precipitated sludge is pumped into the filter press 54 for filter pressing through the conveying of the sludge pump 53, and the dry sludge formed by the filter pressing is transported out through the sludge outward transport equipment 55.

In this embodiment, the biochemical treatment device 6 includes an anoxic tank 61, an aerobic tank 62, an MBR membrane tank 63 and a clean water tank 64, the outflow ends of the condensed water delivery pipe 32 and the sewage delivery pipe 52 enter the anoxic tank 61, a water outlet is formed at the upper part of the anoxic tank 61 for communicating with the aerobic tank 62, and an aerobic tank water outlet is formed at the upper part of the aerobic tank 62 for communicating with the MBR membrane tank 63.

Furthermore, a plurality of aerobic tank aeration heads 621 are provided at the bottom of the aerobic tank 62, a plurality of membrane tank aeration heads 631 are also provided at the bottom of the MBR membrane tank 63, and the aerobic tank aeration heads 621 and the membrane tank aeration heads 631 are connected to a blower 65 provided outside the biochemical treatment apparatus 6 through pipes.

Preferably, an MBR Membrane module 632, also called Membrane Bio-Reactor (Membrane Bio-Reactor), is installed in the aforementioned MBR Membrane tank 63, and is a novel water treatment technology unit combining a Membrane separation unit and a biological treatment unit, and the MBR Membrane module 632 may be an RGE 100/150 type flat Membrane module manufactured by south kyo reijiert Membrane separation technologies ltd; and the MBR membrane module 632 is connected with a self-priming pump 633 through a pipeline, the liquid inlet end of the self-priming pump 633 is communicated with the liquid outlet end of the MBR membrane module 632, and the liquid outlet end of the self-priming pump 633 is communicated with the clean water tank 64 through a pipeline.

Further, a reflux pump 634 is installed at the bottom of the MBR membrane tank 63, a reflux pipe 635 is connected to the reflux pump 634, and the outflow end of the reflux pipe 635 enters the anoxic tank 61.

In this embodiment, the water coming from the anoxic tank 61 is condensed water formed by the MVR evaporation plant 3 and sewage generated by the coagulation sedimentation device 5, and after nitrification-denitrification treatment in the anoxic tank 61 and the aerobic tank 62, most of organic matters and ammonia nitrogen in the sewage water are removed and formed into muddy water by aeration treatment of the aerobic tank aeration head 621 and the membrane tank aeration head 631; further muddy water enters the MBR membrane tank 63, is filtered into clear water through a self-sucking pump 633, is conveyed to the clear water tank 64, and active sludge and microorganisms in the muddy water are left at the bottom of the MBR membrane tank 63, and the sludge water mixture at the bottom of the MBR membrane tank 63 is returned to the anoxic tank 61 through the conveying of the return pump 634 and the return pipe 635 for further denitrification treatment.

In this embodiment, a clear water liquid delivery pipe 73 is further connected to the RO integration apparatus 7, and an outflow end of the clear water liquid delivery pipe 73 enters the clear water tank 64 of the biochemical treatment device 6; the RO integration equipment 7 can make water molecule leachate permeate a reverse osmosis membrane therein by utilizing pressure and intercept molecules larger than 1nm, so that the purpose of treating the leachate is achieved, incoming water in the RO integration equipment 7 is permeate formed in the NF nanofiltration integration equipment 4, wherein the permeate contains a large amount of sodium chloride NACl, the permeate is separated into clear water liquid and concentrated liquid after being fully concentrated by the RO integration equipment 7, the clear water liquid reaching the recycling standard is conveyed into a clear water tank 61 through a clear water conveying pipeline 73 and waits for recycling, a large amount of NaCl contained in the concentrated liquid can be used as a raw material in the chlor-alkali industry, and the concentrated liquid is conveyed into a sodium hypochlorite preparation device 72 through a concentrated liquid conveying pipeline 71 to react.

Please continue to refer to fig. 1 and fig. 2, briefly describing the working process of the present invention: firstly, coal chemical wastewater flows into a pretreatment device 1, and flows into a primary sedimentation tank 12 for sedimentation after larger suspended matters and impurities in the coal chemical wastewater are removed through a mechanical grating 111, the sedimentated coal chemical wastewater further flows into an adjusting tank 13, and the water quality and the water quantity of the coal chemical wastewater are adjusted through the adjusting tank 13; then, the coal chemical industry wastewater is pumped into the CWAO catalytic wet oxidation device 2 by the adjusting tank lift pump 131 arranged in the adjusting tank 13, and the CWAO catalytic oxidation reaction is performed in the CWAO catalytic wet oxidation device 2, so that most of organic matters in the coal chemical industry wastewater are removed and formed into degradation liquid; then, the condensed water is conveyed into an MVR evaporation device 3 through a pipeline to be subjected to evaporation concentration treatment in the next step, the degradation liquid is subjected to evaporation concentration treatment and then is separated into condensed water and coal chemical industry mother liquor, the condensed water is conveyed into a biochemical treatment device 6 through a condensed water conveying pipeline 32, and the coal chemical industry mother liquor is conveyed into an NF nanofiltration integrated device 4 through a mother liquor conveying pipeline 31 to be subjected to separation treatment; the coal chemical industry mother liquor forms permeate and concentrated liquor after nanofiltration operation of the NF nanofiltration integrated equipment 4, univalent ions in the original coal chemical industry mother liquor such as sodium ions and chloride ions permeate and flow into the permeate, the permeate enters the RO integrated equipment 7 through the permeate conveying pipeline 41, divalent and above-divalent ions such as calcium and magnesium ions and organic matters are intercepted and removed from the concentrated liquor, and the concentrated liquor enters the coagulating sedimentation device 5 through the concentrated liquor conveying pipeline 42 for coagulating sedimentation operation; the concentrated solution is formed with sewage and sludge after the coagulation sedimentation treatment by adjusting the pH value and adding PAC (polyaluminium chloride) and PAM (polyacrylamide) in the coagulation sedimentation device 5, the sewage enters the biochemical treatment device 6 through the transportation of a sewage transportation pipeline 52, the precipitated sludge is pumped into a filter press 54 for filter pressing through the transportation of a sludge pump 53, and the dry sludge formed by the filter pressing is transported outside through a sludge outside transportation device 55; the condensed water formed by the MVR evaporation equipment 3 and the sewage generated by the coagulating sedimentation device 5 enter the anoxic tank 61, are formed into muddy water after nitrification-denitrification and aeration treatment and enter the MBR membrane tank 63, the muddy water is filtered by the self-priming pump 633 to form clear water liquid and is conveyed to the clear water tank 64, the active sludge and microorganisms in the muddy water are left at the bottom of the MBR membrane tank 63, and the bottom of the MBR membrane tank 63 is returned to the anoxic tank 61 by the return pump 634 for further denitrification treatment; permeate formed in the NF nanofiltration integrated equipment 4 flows into the RO integrated equipment 7, the permeate is separated into clear water liquid and concentrated liquid after being fully concentrated by the RO integrated equipment 7, the clear water liquid reaching the recycling standard is conveyed into the clear water tank 64 through the clear water conveying pipeline 73 to be recycled, and the concentrated liquid enters the sodium hypochlorite preparation device 72 through the concentrated liquid conveying pipeline 71 to react to generate sodium hypochlorite.

To sum up, the technical solution provided by the present invention remedies the defects in the prior art, successfully completes the invention task, and faithfully embodies the technical effects mentioned in the above technical effect column by the applicant.

Claims

1. A coal chemical wastewater treatment system is characterized by comprising a pretreatment device (1), a CWAO catalytic wet oxidation device (2), an MVR evaporation plant (3), an NF nanofiltration integrated device (4), a coagulating sedimentation device (5), a biochemical treatment device (6) and an RO integrated device (7), wherein a water outlet of the pretreatment device (1) is communicated with a water inlet of the CWAO catalytic wet oxidation device (2) through a pipeline, a water outlet of the CWAO catalytic wet oxidation device (2) is connected with a degradation liquid conveying pipeline (21), the degradation liquid conveying pipeline (21) is communicated with a water inlet of the MVR evaporation plant (3), a mother liquid conveying pipeline (31) and a condensed water conveying pipeline (32) are connected to a liquid outlet end of the MVR evaporation plant (3), and a nanofiltration end of the mother liquid conveying pipeline (31) is communicated with a water inlet of the NF integrated device (4), the outflow end of the condensed water conveying pipeline (32) is communicated with a biochemical treatment device (6), the liquid outlet end of the NF nanofiltration integrated equipment (4) is connected with a permeate conveying pipeline (41) and a concentrated liquid conveying pipeline (42), the outflow end of the permeate liquid conveying pipeline (41) is communicated with the water inlet of the RO integrated equipment (7), the outflow end of the concentrated solution conveying pipeline (42) is communicated with the water inlet of the coagulating sedimentation device (5), the coagulating sedimentation device (5) comprises a sedimentation device (51), a sewage conveying pipeline (52) is connected at the liquid outlet end of the sedimentation equipment (51), the outflow end of the sewage conveying pipeline (52) is communicated with a biochemical treatment device (6), the concentrated solution outlet end of the RO integrated equipment (7) is connected with a concentrated solution conveying pipeline (71), and the other end of the concentrated solution conveying pipeline (71) is connected with a sodium hypochlorite preparation device (72).

2. The coal chemical industry wastewater treatment system according to claim 1, wherein the pretreatment device (1) comprises a grating filter device (11), a primary sedimentation tank (12) and a regulating tank (13), the grating filter device (11) is communicated with a garbage leachate inlet, a mechanical grating (111) is arranged in the grating filtering device (11), a central water inlet cylinder (121) is arranged in the primary sedimentation tank (12), the central water inlet cylinder (121) is connected with the grating filtering device (11) through a pipeline, the outlet of the primary sedimentation tank (12) is connected with the inlet of the regulating tank (13), a regulating tank lift pump (131) is arranged in the regulating tank (13), the adjusting tank lifting pump (131) is communicated with the CWAO catalytic wet oxidation device (2) through a pipeline and can pump water liquid in the adjusting tank (13) into the CWAO catalytic wet oxidation device (2).

3. The coal chemical industry wastewater treatment system according to claim 1, wherein a sludge delivery pipe (511) is connected to the bottom of the sedimentation device (51) of the coagulation sedimentation device (5), the other end, namely the water outlet end, of the sludge delivery pipe (511) is connected with a sludge pump (53), the sludge pump (53) is communicated with a filter press (54) through a pipe, and a sludge transporting device (55) is connected to one side of the filter press (54).

4. The coal chemical wastewater treatment system according to claim 1, wherein the biochemical treatment device (6) comprises an anoxic tank (61), an aerobic tank (62), an MBR membrane tank (63) and a clean water tank (64), the outflow ends of the condensate water conveying pipe (32) and the sewage conveying pipe (52) enter the anoxic tank (61), a water outlet formed at the upper part of the anoxic tank (61) is communicated with the aerobic tank (62), and a water outlet formed at the upper part of the aerobic tank (62) is communicated with the MBR membrane tank (63).

5. The coal chemical wastewater treatment system according to claim 4, characterized in that a plurality of aerobic tank aeration heads (621) are arranged at the bottom of the aerobic tank (62), a plurality of membrane tank aeration heads (631) are also arranged at the bottom of the MBR membrane tank (63), and the aerobic tank aeration heads (621) and the membrane tank aeration heads (631) are communicated with a blower (65) arranged outside the biochemical treatment device (6) through pipelines.

6. The coal chemical wastewater treatment system according to claim 4, wherein the MBR membrane module (632) is installed in the MBR membrane tank (63), the MBR membrane module (632) is connected with a self-priming pump (633) through a pipeline, the inlet end of the self-priming pump (633) is communicated with the outlet end of the MBR membrane module (632), and the outlet end of the self-priming pump (633) is communicated with the clean water tank (64) through a pipeline.

7. The coal chemical industry wastewater treatment system according to claim 4, characterized in that a reflux pump (634) is further installed at the bottom of the MBR membrane tank (63), a reflux pipe (635) is connected to the reflux pump (634), and the outflow end of the reflux pipe (635) enters the anoxic tank (61).

8. The coal chemical industry wastewater treatment system according to claim 4, wherein a clear water liquid delivery pipe (73) is further connected to the RO integrated device (7), and an outflow end of the clear water liquid delivery pipe (73) enters the clear water tank (64) of the biochemical treatment device (6).