Advanced treatment system for biochemical effluent of coal chemical wastewater

Abstract

The utility model relates to an advanced treatment system for biochemical effluent of coal chemical wastewater. The system comprises a pretreatment unit, a tubular membrane microfiltration treatment unit and a reverse osmosis treatment unit, the pretreatment unit comprises a sedimentation tank and a reaction tank which are communicated with each other, and the sedimentation tank receives biochemical effluent; the tubular membrane microfiltration treatment unit comprises a concentration tank, a first delivery pump, a tubular membrane microfiltration treatment device and a water producing tank, the concentration tank is connected with the reaction tank, the concentration tank is communicated with the tubular membrane microfiltration treatment device through the first delivery pump, a concentrated water outlet of the tubular membrane microfiltration treatment device is connected with the concentration tank, and a water outlet of the tubular membrane microfiltration treatment device is connected with the water producing tank; the water producing tank is connected with the tubular membrane microfiltration treatment device; the reverse osmosis treatment unit comprises a second delivery pump and a reverse osmosis treatment device; the water producing tank is connected with the reverse osmosis treatment device through a second conveying pump; and a diatomite adding device is arranged above the sedimentation tank. By adopting the system, the hardness and COD content of biochemical effluent of the coal chemical industry wastewater can be reduced, the operation pressure of the system is relieved, and the cost is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment, in particular to a deep treatment system for biochemical effluent of coal chemical wastewater. Background Technique

[0002] The coal chemical industry uses coal as raw material, and through chemical processing, coal is converted into gaseous, liquid, solid fuels and chemical products. It is mainly divided into coal coking, coal gasification, coal gasification to synthesize ammonia, coal gasification to synthesize other products and direct liquefaction, etc. The wastewater generated in the coal chemical industry is a high-concentration and difficult-to-degrade process wastewater with high chemical oxygen demand, high chroma and high turbidity.

[0003] At present, the coal chemical wastewater at home and abroad generally adopts the process of pretreatment + biochemical treatment + deep treatment of biochemical effluent. After most of the COD, solid suspended matter and emulsified oil are removed through pretreatment and biochemical treatment, the wastewater COD can be reduced to 100-300mg / L. However, the remaining part of the COD index is mainly some refractory polycyclic and heterocyclic organic substances, with poor biodegradability. There is still a certain gap between the chroma, TDS, ammonia nitrogen and other indexes and the boiler reuse water indexes, and deep treatment is required to further remove pollutants such as COD and salts. At the same time, considering that China's coal chemical projects are mainly distributed in areas with relatively rich coal resources such as Shaanxi, Shanxi and Gansu, and the water resources in these areas are extremely scarce, the new coal chemical projects usually adopt the dual-membrane method to further process the biochemical effluent into boiler feed water.

[0004] Chinese Patent CN20237985 discloses a zero-discharge treatment system for coal chemical sewage, which includes a flotation device, a Fenton oxidation device, a biological oxidation device, an ultrafiltration device, a reverse osmosis device and an evaporation crystallization device connected in sequence. There is an adjustment tank on one side of the Fenton oxidation device, and a pH value adjustment device is arranged in the adjustment tank; one side of the adjustment tank is connected to the biochemical treatment device, and a sedimentation tank and an ultrafiltration inlet tank are arranged between the biochemical treatment device and the ultrafiltration device. One side of the ultrafiltration device is connected to the ultrafiltration inlet tank, and the other side is connected to the ultrafiltration product tank. The other side of the ultrafiltration product tank is connected to the reverse osmosis device, and the concentrated water side of the reverse osmosis device is connected to the evaporation crystallization device. Due to the complex composition of coal chemical wastewater, there is still 100-300mg / L of COD after biological oxidation. This method does not consider that the high organic matter concentration is likely to cause fouling of the subsequent membrane treatment unit, reducing the life and treatment effect of the reverse osmosis membrane during long-term operation, causing great losses to production operation. Content of the Utility Model

[0005] The technical problem to be solved by the utility model is: how to reduce the hardness, turbidity and organic matter concentration of the biochemical effluent of coal chemical wastewater.

[0006] In view of the deficiencies of the existing technology, the purpose of the present invention is to provide a solid-liquid separation system for the biochemical effluent of coal chemical wastewater, which can reduce the hardness and turbidity of the biochemical effluent while effectively reducing the COD value, relieve the operation pressure of the subsequent treatment process, and save costs.

[0007] The technical solution of the present utility model:

[0008] The present utility model provides a deep treatment system for the biochemical effluent of coal chemical wastewater, which includes a pretreatment unit, a tubular membrane microfiltration treatment unit, and a reverse osmosis treatment unit.

[0009] Among them, the pretreatment unit includes a sedimentation tank and a reaction tank that are connected in communication, and the sedimentation tank receives the biochemical effluent of coal chemical wastewater.

[0010] The tubular membrane microfiltration treatment unit includes a concentration tank, a first transfer pump, a tubular membrane microfiltration treatment device, and a product water tank. The concentration tank is connected in communication with the reaction tank. One end of the first transfer pump is connected to the inlet of the tubular membrane microfiltration treatment device, and the other end is connected to the concentration tank. The concentrated water outlet of the tubular membrane microfiltration treatment device is connected to the concentration tank, and the product water tank is connected to the product water outlet of the tubular membrane microfiltration treatment device.

[0011] The reverse osmosis treatment unit includes a second transfer pump and a reverse osmosis treatment device; one end of the second transfer pump is connected to the product water tank, and the other end is connected to the reverse osmosis treatment device.

[0012] A diatomaceous earth dosing device is provided above the sedimentation tank.

[0013] In some embodiments of the present utility model, a polyaluminum chloride dosing device and a first liquid caustic soda dosing device are also provided above the sedimentation tank.

[0014] In some embodiments of the present utility model, a sodium hypochlorite dosing device, a second liquid caustic soda dosing device, a lime dosing device, and a sodium carbonate dosing device are provided above the reaction tank.

[0015] In some embodiments of the present utility model, the tubular membrane microfiltration treatment unit further includes a cleaning device.

[0016] In some embodiments of the present utility model, the cleaning device includes a cleaning pump and a cleaning water tank. One end of the cleaning pump is connected to the cleaning water tank through a pipeline, and the other end is connected to the inlet of the tubular membrane microfiltration treatment device through a pipeline. The concentrated water outlet of the tubular membrane microfiltration treatment device is connected to the cleaning water tank through a pipeline.

[0017] In some embodiments of the present utility model, the pretreatment unit further includes a sludge sedimentation tank, and the sludge sedimentation tank is connected to the concentration tank.

[0018] In some embodiments of the present utility model, the membrane material of the tubular membrane microfiltration treatment device is polyethylene and / or polyvinylidene fluoride.

[0019] In some embodiments of the present utility model, the surface pore diameter of the membrane material of the tubular membrane microfiltration treatment device is 0.01 - 1 micron.

[0020] Advantages of the present utility model:

[0021] The advanced treatment system for biochemical effluent of coal chemical wastewater in the present utility model uses a diatomite dosing device to add diatomite into the sedimentation tank. Colloids, heavy metal ions, and organic substances in the biochemical effluent of coal chemical wastewater are adsorbed on the surface of the diatomite and fixed on the surface of the diatomite through chemical reactions. Then, solid-liquid separation is achieved through the tubular microfiltration membrane treatment device, thereby reducing the hardness and turbidity of the biochemical effluent of coal chemical wastewater while effectively reducing the concentration of organic substances in the water body, relieving the operating pressure of the subsequent treatment process, and saving costs. Description of the drawings

[0022] Figure 1 Schematic diagram of the advanced treatment system for biochemical effluent of coal chemical wastewater in Example 1;

[0023] Figure 2 Schematic diagram of the advanced treatment system for biochemical effluent of coal chemical wastewater in Example 2;

[0024] Figure 3 Schematic diagram of the advanced treatment system for biochemical effluent of coal chemical wastewater in Comparative Example 1.

[0025] Explanation of the markings in the figure is as follows:

[0026] 1 - sedimentation tank, 2 - diatomite dosing tank, 3 - reaction tank, 4 - thickening tank, 5 - first delivery pump, 6 - inlet of the tubular membrane microfiltration treatment device, 7 - tubular membrane microfiltration treatment device, 8 - concentrated water outlet of the tubular membrane microfiltration treatment device, 9 - product water outlet of the tubular membrane microfiltration treatment device, 10 - product water tank, 11 - second delivery pump, 12 - reverse osmosis treatment device, 13 - concentrated water outlet of the reverse osmosis treatment device, 14 - product water outlet of the reverse osmosis treatment device, 15 - polyaluminum chloride dosing tank, 16 - first liquid caustic soda dosing tank, 17 - second liquid caustic soda dosing tank, 18 - sodium hypochlorite dosing tank, 19 - lime dosing tank, 20 - sodium carbonate dosing tank, 21 - cleaning pump, 22 - cleaning water tank, 23 - first valve, 24 - second valve, 25 - sludge sedimentation tank, 26 - water outlet of the sludge sedimentation tank, 27 - sludge outlet of the sludge sedimentation tank, 28 - third valve, 29 - coagulation sedimentation tank, 30 - V-shaped filter, 31 - ultrafiltration membrane treatment device, 32 - resin adsorption tank. Detailed implementation manners

[0027] For the purpose of making the objectives, technical solutions and technical effects of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model are described clearly and completely. The embodiments described below are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art in combination with the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0028] It should be noted that relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include" and "comprise" are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or device.

[0029] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by terms such as "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "inner", "outer", "top", "bottom", "end" etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, specific orientation structure and operation. Therefore, it should not be construed as a limitation to the present utility model.

[0030] In a specific embodiment of the present utility model, the present utility model provides a deep treatment system for biochemical effluent of coal chemical wastewater, which includes a pretreatment unit, a tubular membrane microfiltration treatment unit and a reverse osmosis treatment unit connected in sequence.

[0031] Among them, the pretreatment unit includes a sedimentation tank and a reaction tank connected in communication, and the sedimentation tank receives the biochemical effluent of coal chemical wastewater.

[0032] The tubular membrane microfiltration treatment unit includes a concentration tank, a first delivery pump, a tubular membrane microfiltration treatment device and a product water tank. The concentration tank is connected in communication with the reaction tank. One end of the first delivery pump is connected to the inlet of the tubular membrane microfiltration treatment device, and the other end is connected to the concentration tank. The concentrated water outlet of the tubular membrane microfiltration treatment device is connected to the reaction tank, and the product water tank is connected to the product water outlet of the tubular membrane microfiltration treatment device.

[0033] The reverse osmosis treatment unit includes a second delivery pump and a reverse osmosis treatment device. One end of the second delivery pump is connected to the product water tank, and the other end is connected to the reverse osmosis treatment device.

[0034] A diatomite dosing device is provided above the sedimentation tank.

[0035] In some embodiments of the present utility model, a polyaluminum chloride dosing device and a first liquid caustic soda dosing device are further provided above the sedimentation tank.

[0036] In some embodiments of the present utility model, a sodium hypochlorite dosing device, a second liquid caustic soda dosing device, a lime dosing device and a sodium carbonate dosing device are provided above the reaction tank.

[0037] In wastewater treatment, diatomite is used as a filter aid. Its fine particles can form a filter layer with large pores and surface area, which can effectively filter substances such as suspended solids, colloidal particles and microorganisms, thereby improving the clarity of water. And with a large specific surface area and many hydroxyl (OH) groups, it can adsorb heavy metal ions, organic substances and other pollutants in water, and fix them on the surface of diatomite through chemical reactions, thus achieving the removal of harmful substances in water. At the same time, the hydroxyl groups can adjust the pH value of water to keep it within a suitable range, which helps to maintain the stability of the water body. Diatomite has certain biological activity, can adsorb and inhibit the reproduction of microorganisms such as bacteria, algae and odor substances in water, and effectively improve water quality. And the core of the tubular microfiltration membrane is to use its high solid content tolerance and wear resistance performance to carry out solid-liquid separation of pollutants in wastewater, and it has a broad spectrum of chemical tolerance. Therefore, using a tubular microfiltration membrane treatment device to carry out solid-liquid separation on the wastewater adsorbed by diatomite can effectively remove heavy metal ions, organic substances and other pollutants in the wastewater, and reduce the hardness and COD content of the wastewater.

[0038] Furthermore, while adding diatomite to the sedimentation tank, a coagulant polyaluminum chloride (PAC) and a clarifying agent liquid caustic soda are also added. After sufficient reaction, it enters the reaction tank, and sodium hypochlorite, lime, sodium carbonate and liquid caustic soda are added. After sufficient reaction, it overflows into the concentration tank of the tubular microfiltration treatment unit, and then a first transfer pump is used to send the water in the concentration tank to the tubular membrane microfiltration treatment device for solid-liquid separation, which can further improve the removal effect. The concentrated water re-enters the concentration tank from the concentrated water outlet of the tubular membrane microfiltration treatment device. At this time, a large flow of water circulates between the concentration tank and the tubular membrane microfiltration treatment device, and part of the water permeated through the membrane enters the product water tank through the product water outlet of the tubular membrane microfiltration treatment device. Finally, a second transfer pump is used to send the water in the product water tank to the reverse osmosis device for treatment. The product water of the reverse osmosis treatment device is discharged or reused through the water outlet of the reverse osmosis device, and the concentrated water is discharged from the concentrated water outlet of the reverse osmosis device for further treatment.

[0039] The following further illustrates the advanced treatment system for biochemical effluent of coal chemical wastewater of the present utility model through specific embodiments.

[0040] Example 1

[0041] As shown Figure 1 in the figure, a deep treatment system for the biochemical effluent of coal chemical industry wastewater includes a pretreatment unit, a tubular membrane microfiltration treatment unit and a reverse osmosis treatment unit.

[0042] Among them, the pretreatment unit includes a sedimentation tank 1 and a reaction tank 3 which are connected in communication. The sedimentation tank 1 receives the biochemical effluent of coal chemical industry wastewater.

[0043] The tubular membrane microfiltration treatment unit includes a concentration tank 4, a first transfer pump 5, a tubular membrane microfiltration treatment device 7 and a product water tank 10. The concentration tank 4 is connected to the reaction tank 3. One end of the first transfer pump 5 is connected to the inlet 6 of the tubular membrane microfiltration treatment device 7, and the other end is connected to the bottom of the concentration tank 4. The concentrated water outlet 8 of the tubular membrane microfiltration treatment device is connected to the concentration tank 4. The product water tank 10 is connected to the product water outlet 9 of the tubular membrane microfiltration treatment device.

[0044] The reverse osmosis treatment unit includes a second transfer pump 11 and a reverse osmosis treatment device 12. One end of the second transfer pump 11 is connected to the product water tank 10, and the other end is connected to the reverse osmosis treatment device 12. The reverse osmosis treatment device 12 is also provided with a product water outlet 14 of the reverse osmosis treatment device and a concentrated water outlet 13 of the reverse osmosis treatment device.

[0045] Above the sedimentation tank 1, there are a diatomite dosing tank 2, a polyaluminum chloride dosing tank 15 and a first liquid caustic soda dosing tank 16.

[0046] Above the reaction tank 3, there are a sodium hypochlorite dosing tank 18, a second liquid caustic soda dosing tank 17, a lime dosing tank 19 and a sodium carbonate dosing tank 20.

[0047] Among them, the material of the tubular membrane in the tubular membrane microfiltration treatment device is polyvinylidene fluoride, and the surface pore size is 0.05 microns.

[0048] Working principle:

[0049] The biochemical effluent of coal chemical industry wastewater after biochemical treatment enters the first reaction tank 1. Diatomaceous earth is added to the first reaction tank 1 through the diatomaceous earth dosing tank 2, and the coagulant polyaluminum chloride is added through the polyaluminum chloride dosing tank and liquid alkali is added through the first liquid alkali dosing tank for reaction. The effluent of sedimentation tank 1 overflows into reaction tank 3, and sodium hypochlorite is added to reaction tank 3 through the sodium hypochlorite dosing tank for sterilization. Lime is added through the limestone dosing tank 19, liquid alkali is added through the second liquid alkali dosing tank, and sodium carbonate is added through the sodium carbonate dosing tank 20 for softening treatment. The effluent of reaction tank 3 overflows into the concentration tank 4 for collection, and then the water in the concentration tank 4 is sent to the tubular membrane microfiltration treatment device 7 by the first delivery pump 5 for solid-liquid separation. The concentrated water re-enters the concentration tank 4 from the concentrated water outlet 8 of the tubular membrane microfiltration treatment device. At this time, a large flow of water circulates between the concentration tank 4 and the tubular membrane microfiltration treatment device 7, and part of the water permeated through the membrane enters the product water tank 10 through the product water outlet 9 of the tubular membrane microfiltration treatment device. Finally, the water in the product water tank 10 is sent to the reverse osmosis treatment device 12 by the second delivery pump 11 for treatment. The product water of the reverse osmosis treatment device 12 is discharged or reused through the product water outlet 14 of the reverse osmosis treatment device, and the concentrated water is discharged from the concentrated water outlet 13 of the reverse osmosis treatment device for further treatment.

[0050] Example 2

[0051] As Figure 2 shown, a deep treatment system for the biochemical effluent of coal chemical industry wastewater, which is different from that in Example 1 in that:

[0052] The deep treatment system for the biochemical effluent of coal chemical industry wastewater further includes a cleaning device, which includes a cleaning pump 21 and a cleaning water tank 22. One end of the cleaning pump 21 is connected to the cleaning water tank 22 through a pipeline, and the other end is connected to the inlet 6 of the tubular membrane microfiltration treatment device through a pipeline. A first valve 23 is provided on the pipeline connecting the cleaning pump 21 and the inlet 6 of the tubular membrane microfiltration treatment device. The concentrated water outlet 8 of the tubular membrane microfiltration treatment device is connected to the cleaning water tank 22 through a pipeline, and a second valve 24 is provided on the pipeline connecting the concentrated water outlet 8 of the tubular membrane microfiltration treatment device and the cleaning water tank 22;

[0053] The deep treatment system for the biochemical effluent of coal chemical industry wastewater further includes a sludge sedimentation tank 25, which is connected to the bottom of the concentration tank 4, and a third valve 28 is provided on the pipeline connecting the sludge sedimentation tank 25 and the concentration tank 4;

[0054] Working principle:

[0055] Treat the biochemical effluent of coal chemical wastewater according to the method of Example 1. When it is necessary to clean the tubular membrane microfiltration treatment device, close the first delivery pump 5 and the second delivery pump 11, open the first valve 23, the second valve 24 and the third delivery pump 21, and use the cleaning water in the cleaning water tank 22 to clean the tubular membrane microfiltration treatment device 7;

[0056] When there is more sludge in the thickening tank, open the third valve, and the mud-water mixture at the bottom of the thickening tank enters the sludge sedimentation tank 25. After static separation, the sludge at the bottom is sent to the plate and frame filter press for dehydration treatment through the sludge outlet 27 of the sludge sedimentation tank, and the upper clear water of the sludge sedimentation tank 25 returns to the sedimentation tank 1 through the water outlet 26 of the sludge sedimentation tank.

[0057] Comparative Example 1

[0058] The advanced treatment system for the biochemical effluent of coal chemical wastewater in Comparative Example 1 includes a coagulation sedimentation tank 29, a V-shaped filter tank 30, an ultrafiltration membrane treatment device 31, a resin adsorption tank 32, and a reverse osmosis treatment device 12 connected in sequence.

[0059] The biochemical effluent of coal chemical wastewater is treated successively through the coagulation sedimentation tank 29, the V-shaped filter tank 30, the ultrafiltration membrane treatment device 31, the resin adsorption tank 32, and the reverse osmosis treatment device 12.

[0060] Experimental Example

[0061] Treat the biochemical effluent of coal chemical wastewater with the wastewater treatment systems of Example 1 and Comparative Example 1 respectively. Among them, in the advanced treatment system of Example 1, the addition amount of diatomite is 250 mg / L, the addition amount of polyaluminum chloride is 100 mg / L, the addition amount of the first liquid caustic soda is 30 mg / L; the addition amount of sodium hypochlorite (effective concentration) is 100 mg / L, the addition amount of sodium carbonate is 100 mg / L, the addition amount of lime is 250 mg / L, and the addition amount of the second liquid caustic soda is 300 mg / L.

[0062] The medicament added in the coagulation sedimentation tank in Comparative Example 1 is: the addition amount of polyaluminum chloride is 50 mg / L.

[0063] The experimental results are shown in Table 1:

[0064] Table 1 Treatment results of the advanced treatment systems of Example 1 and Comparative Example 1

[0065] COD, mg / L Calcium ion, mg / L Magnesium ion, mg / L Biochemical effluent before treatment 112 190 150 After treatment in Example 1 74 20 25 After treatment in Comparative Example 1 108 35 40

[0066] As can be seen from Table 1, although Comparative Example 1 can reduce the hardness of the biochemical effluent of coal chemical wastewater, the removal effect on COD is not obvious. However, by using the advanced treatment system for the biochemical effluent of coal chemical wastewater of the present utility model, not only can the hardness of the biochemical effluent of coal chemical wastewater be reduced, but also the content of COD in the biochemical effluent of coal chemical wastewater can be significantly reduced, relieving the operation pressure of the subsequent treatment process and saving the wastewater treatment cost at the same time.

[0067] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present utility model and not to limit them. Although the present utility model has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and details without departing from the scope defined by the claims of the present utility model.

Claims

1. A deep treatment system for the biochemical effluent of coal chemical industry wastewater, characterized in that, It includes a pretreatment unit, a tubular membrane microfiltration treatment unit and a reverse osmosis treatment unit. Among them, the pretreatment unit includes a sedimentation tank and a reaction tank that are connected and communicate with each other. The sedimentation tank receives the biochemical effluent of coal chemical wastewater. The tubular membrane microfiltration treatment unit includes a concentration tank, a first transfer pump, a tubular membrane microfiltration treatment device and a product water tank. The concentration tank is connected and communicates with the reaction tank. One end of the first transfer pump is connected to the inlet of the tubular membrane microfiltration treatment device, and the other end is connected to the concentration tank. The concentrated water outlet of the tubular membrane microfiltration treatment device is connected to the concentration tank, and the product water tank is connected to the product water outlet of the tubular membrane microfiltration treatment device. The reverse osmosis treatment unit includes a second transfer pump and a reverse osmosis treatment device. One end of the second transfer pump is connected to the product water tank, and the other end is connected to the reverse osmosis treatment device. A diatomaceous earth dosing device is provided above the sedimentation tank.

2. The advanced treatment system for the biochemical effluent of coal chemical wastewater according to claim 1, wherein A polyaluminum chloride dosing device and a first liquid caustic soda dosing device are also provided above the sedimentation tank.

3. The advanced treatment system for biochemical effluent of coal chemical wastewater according to claim 1, characterized in that A sodium hypochlorite dosing device, a second liquid caustic soda dosing device, a lime dosing device and a sodium carbonate dosing device are provided above the reaction tank.

4. The advanced treatment system for the biochemical effluent of coal chemical wastewater according to claim 2, wherein A sodium hypochlorite dosing device, a second liquid caustic soda dosing device, a lime dosing device and a sodium carbonate dosing device are provided above the reaction tank.

5. The advanced treatment system for the biochemical effluent of coal chemical wastewater according to any one of claims 1-4, characterized in that, The tubular membrane microfiltration treatment unit further includes a cleaning device.

6. The advanced treatment system for the biochemical effluent of coal chemical wastewater according to claim 5, characterized in that, The cleaning device includes a cleaning pump and a cleaning water tank. One end of the cleaning pump is connected to the cleaning water tank through a pipeline, and the other end is connected to the inlet of the tubular membrane microfiltration treatment device through a pipeline. The concentrated water outlet of the tubular membrane microfiltration treatment device is connected to the cleaning water tank through a pipeline.

7. The advanced treatment system for the biochemical effluent of coal chemical wastewater according to any one of claims 1-4, characterized in that, The pretreatment unit further includes a sludge sedimentation tank, and the sludge sedimentation tank is connected to the concentration tank.

8. The advanced treatment system for the biochemical effluent of coal chemical wastewater according to any one of claims 1-4, characterized in that, The membrane material of the tubular membrane microfiltration treatment device is polyethylene and / or polyvinylidene fluoride.

9. The advanced treatment system for biochemical effluent of coal chemical wastewater according to any one of claims 1-4, characterized in that, The surface pore size of the membrane material of the tubular membrane microfiltration treatment device is 0.01 - 1 micron.

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