CN-118289976-B - Device and method for deeply treating organic matters in coal chemical reverse osmosis membrane filtered concentrate

CN118289976BCN 118289976 BCN118289976 BCN 118289976BCN-118289976-B

Abstract

A device and a method for deeply treating organic matters in coal chemical reverse osmosis membrane filtered concentrate relate to a device and a method for treating membrane filtered concentrate, and aim to solve the technical problems of easy scaling, high energy consumption and long treatment time of the existing membrane filtered concentrate treatment method. The device comprises a heat exchanger, a high-grade oxidation tank, an electric flocculation coupling electric oxidation tank and a sedimentation tank which are sequentially connected, wherein a persulfate adding system is connected with the high-grade oxidation tank, and meanwhile, the electric flocculation coupling electric oxidation tank and the sedimentation tank are provided with return pipes which are connected to the high-grade oxidation tank. The sulfate radical is generated by using thermal activation and Fe 2+ ion activation through a combination mode of advanced oxidation and electroflocculation coupling electrooxidation, and the sulfate radical reacts with the original chloride ion to generate active chlorine, so that refractory organic matters in reverse osmosis concentrated water are oxidized and degraded, the scaling problem of a subsequent evaporation crystallization system is reduced, and the organic matters are thoroughly separated from crystal salt. The invention can be used in the field of sewage treatment.

Inventors

DING JING
JIANG XIAOWEN
ZHANG YUYAN
YAN HUI
LI YULONG
GUO LEI
YAN XUEYA
DAI JINGUO
ZHAI XUEDONG

Assignees

哈尔滨工业大学
中天合创能源有限责任公司
鄂尔多斯市安信泰环保科技有限公司

Dates

Publication Date: 20260505
Application Date: 20240507

Claims (7)

1. A method for deeply treating organic matters in coal chemical reverse osmosis membrane filtered concentrate is characterized by comprising the following steps of; 1. The device for deeply treating the organic matters in the coal chemical reverse osmosis membrane filtered concentrated water comprises a heat exchanger (1), a persulfate adding system (2), a high-grade oxidation pond (3), an electroflocculation coupling electrooxidation pond (4) and a sedimentation pond (5); the heat exchanger (1) consists of an internal coil pipe (1-1) and an outer sleeve box body (1-2), wherein the internal coil pipe (1-1) is a bent pipeline, and a steam inlet is arranged at the bottom of the outer sleeve box body (1-2); The persulfate adding system (2) consists of a persulfate storage tank (2-1), an adding pump (2-2) and an adding pipeline (2-3), wherein the persulfate storage tank (2-1) is subjected to sealing treatment to prevent the persulfate from being oxidized by contact with air; The side wall of the advanced oxidation pond (3) is provided with a water inlet (3-1) and a reflux liquid inlet (3-2), the upper part of the opposite pond wall is provided with a water outlet (3-3), the bottom of the conical pond is provided with a mud discharging port (3-4), the pond is internally provided with a first hydraulic stirring device (3-5), the heat exchanger (1) is connected with the water inlet (3-1) of the advanced oxidation pond (3) through a built-in coil pipe (1-1), and the persulfate storage tank (2-1) is connected with the advanced oxidation pond (3) through a feeding pump (2-2) and a feeding pipeline (2-3); The method comprises the steps of arranging a cathode plate (4-1) and an anode plate (4-2) which are opposite in an electroflocculation coupling electrooxidation pond (4), fixing a plurality of groups of bipolar plates (4-3) which are perpendicular to the cathode plate (4-1) and the anode plate (4-2) and are arranged at equal intervals between the cathode plate (4-1) and the anode plate (4-2) by using a supporting frame, connecting the cathode plate (4-1) and the anode plate (4-2) with positive and negative poles of a direct current power supply (4-4), arranging electrode main surfaces of the plurality of groups of bipolar plates (4-3) in parallel with electric field lines formed by the positive and negative poles, arranging an inlet (4-5) at the upper part of the side wall of the electroflocculation coupling electrooxidation pond (4), arranging a communicating outlet (4-6) at the middle part of the opposite side wall of the electroflocculation coupling electrooxidation pond, arranging a reflux outlet (4-7) at the bottom of the pond, arranging a reflux pump (4-8) and a reflux control valve (4-9) on the pipeline, and arranging a reflux pump (4-8) and a second stirring device (4-10) under the cathode plate (4-1). The middle part of the side wall of the sedimentation tank (5) is provided with a communication inlet (5-1), the communication inlet (5-1) is connected with a communication outlet (4-6) of the electroflocculation coupling electrooxidation tank (4), the upper part of the opposite side wall of the sedimentation tank (5) is provided with an overflow port (5-2), the conical bottom of the sedimentation tank (5) is provided with a mud discharge pipe (5-3), the mud discharge pipe (5-3) is provided with a branch pipe which is connected with a reflux liquid inlet (3-2) of the advanced oxidation tank (3), and the branch pipe is provided with a floc reflux pump (5-4) and a floc reflux control valve (5-5); Inputting reverse osmosis membrane filtered concentrate into a built-in coil (1-1) of a heat exchanger (1), heating to 80-90 ℃ through steam, entering into an advanced oxidation pond (3), adding persulfate in a persulfate storage tank (2-1) into the advanced oxidation pond (3) through a feeding pump (2-2) and a feeding pipeline (2-3), simultaneously, enabling liquid flowing back from an electroflocculation coupling electrooxidation pond (4) and flocs flowing back from a sedimentation pond (5) to enter into the advanced oxidation pond (3), wherein the reflux ratio of the liquid flowing back from the electroflocculation coupling electrooxidation pond (4) is 50-100%, the reflux ratio of the flocs flowing back from the sedimentation pond (5) is 90-100%, the stirring rate is 1400-150 rpm, and the hydraulic retention time of the reverse osmosis membrane filtered concentrate in the advanced oxidation pond (3) is 0.5-2 h; 2. Then the reverse osmosis membrane filtered concentrated water enters an electric flocculation coupling electric oxidation pond (4), the current density of a direct current power supply is set to be 20-200 mA/cm 2 , the stirring speed is 1400-1500 rpm, and the hydraulic retention time of the reverse osmosis concentrated water in the electric flocculation coupling electric oxidation pond (4) is 0.5-3 h; 3. After the reverse osmosis membrane filtered concentrate enters a sedimentation tank (5), electric flocculation flocs are settled at the bottom to form iron-containing sludge, a part of the iron-containing sludge is recycled to a high-grade oxidation tank, a part of the iron-containing sludge is discharged, and the treated water is discharged through an overflow port (5-2) to finish the advanced treatment of organic matters in the coal chemical reverse osmosis membrane filtered concentrate.
2. The method for deeply treating organic matters in coal chemical reverse osmosis membrane filtered concentrate water according to claim 1, wherein the inner surfaces of the built-in coil (1-1) and the conveying pipeline of the heat exchanger (1) are plated with teflon plating layers.
3. The method for deeply treating organic matters in reverse osmosis membrane filtered concentrate water in coal chemical industry according to claim 1 or 2, wherein a filter screen is arranged at the water outlet (3-3).
4. The method for deeply treating organic matters in reverse osmosis membrane filtered concentrate water in coal chemical industry according to claim 1 or 2 is characterized in that a cathode plate (4-1) in an electroflocculation coupling electrooxidation pond (4) is a graphite electrode, a carbon felt, a stainless steel electrode, a carbon plate or a titanium plate, an anode plate (4-2) is a coated titanium anode, a lead dioxide electrode or a carbon plate electrode, and a bipolar plate (4-3) is a rectangular iron plate.
5. The method for deeply treating organic matters in reverse osmosis membrane filtered concentrate water in coal chemical industry according to claim 1 or 2, wherein the upper part of the sedimentation tank (5) is cylindrical, and the lower part is conical.
6. The method for deeply treating organic matters in reverse osmosis membrane filtered concentrate water in coal chemical industry according to claim 1 or 2, characterized in that a pipe chute filler (5-6) is arranged under an overflow port (5-2) of the sedimentation tank (5).
7. The method for deeply treating organic matters in reverse osmosis membrane filtered concentrate in coal chemical industry according to claim 1 or 2, characterized in that the device for deeply treating organic matters in reverse osmosis membrane filtered concentrate in coal chemical industry further comprises an evaporation crystallizer (6), wherein a steam pipe of the evaporation crystallizer (6) is connected with a steam inlet arranged at the bottom of an outer sleeve box body (1-2) of the heat exchanger (1).

Description

Device and method for deeply treating organic matters in coal chemical reverse osmosis membrane filtered concentrate Technical Field The invention relates to a device and a method for deeply treating membrane filtration concentrated solution, belonging to the field of sewage treatment. Background The wastewater produced in the production process of coal chemical enterprises needs to be recycled, but the high-salt wastewater mainly comes from reverse osmosis concentrated water produced by a membrane separation unit, and the concentrated water has the characteristics of extremely high organic matter content, high salt content, poor biodegradability and complex components, and is difficult to thoroughly degrade by biochemical treatment. The existing method for evaporating and crystallizing the high-salt wastewater not only can recycle the produced water, but also can recycle the crystallized salt from the concentrated water as a byproduct, and a large amount of waste heat resources generated in the evaporating and crystallizing process can be recycled. However, in this method, high concentration of organic matters remain in the solid as the crystallization salt is precipitated during the evaporation. Even though the crystalline salt can recover 80% or more of sodium chloride and sodium sulfate, it is classified as hazardous waste due to the inclusion of organic impurities, and disposal costs are high. And the generated large amount of scaling causes unstable operation of the subsequent evaporative crystallization system, frequent cleaning or equipment replacement is required, and the operation management cost is increased. How to carry out advanced treatment on reverse osmosis concentrated water, the concentration of organic matters can be reduced as much as possible, the scaling problem on the surface of an evaporator is reduced, and the recycling of crystallized salt is a key problem to be solved urgently. The main technologies of advanced treatment of membrane filtration concentrate at present are membrane distillation, electrodialysis, constructed wetland and advanced oxidation. Wherein, the membrane distillation process equipment is simple, and the plant steam can be utilized as energy source by local material, but the efficiency of the equipment is easily reduced due to scaling in actual operation. The novel forms of electrodialysis reversal frequently, bipolar membrane electrodialysis and the like have good corrosion resistance, are suitable for concentrating inorganic salt wastewater, and have higher energy consumption and operation cost. The constructed wetland has the advantages of low cost and simultaneously removes organic matters and heavy metals, but the construction time of the system is long and the additional benefit is lacked. Advanced oxidation technology is widely applied, but lacks of deep research of application to coal chemical industry, and uneconomical operation is also a factor limiting practical engineering application. Disclosure of Invention The application aims to solve the technical problems of easy scaling, high energy consumption and long treatment time of the existing treatment method of the membrane filtration concentrate, and provides a device and a method for deeply treating organic matters in the coal chemical reverse osmosis membrane filtration concentrate. The device generates sulfate radical by using heat activation and Fe 2+ ion activation through a high-grade oxidation and electroflocculation coupling electrooxidation combination mode, and reacts with the original chloride ion to generate active chlorine, so that refractory organic matters in reverse osmosis concentrated water are oxidized and degraded, the scaling problem of a subsequent evaporation crystallization system is reduced, the organic matters are thoroughly separated from crystal salt, and the quality of the crystal salt is improved. And (3) recycling waste heat resources generated in the evaporation and crystallization process, and using the waste heat resources for thermally activating the PDS, so that the resource utilization rate is improved, and the operation investment cost is further reduced. Meanwhile, sludge and ferrous ions generated by electric flocculation and electric oxidation are reused for catalyzing advanced oxidation reaction, so that the resource utilization and the clean production of high-salt wastewater zero emission are realized. The invention relates to a device for deeply treating organic matters in coal chemical reverse osmosis membrane filtered concentrate water, which comprises a heat exchanger 1, a persulfate adding system 2, a high-grade oxidation pond 3, an electroflocculation coupling electrooxidation pond 4 and a sedimentation pond 5; The heat exchanger 1 consists of an internal coil pipe 1-1 and an external box body 1-2, wherein the internal coil pipe 1-1 is a bent pipeline, and a steam inlet is arranged at the bottom of the external box body 1-2. The water body in the bui