Advanced treatment device for biochemical effluent of coal chemical wastewater

Abstract

The utility model relates to the technical field of wastewater treatment, in particular to an advanced treatment device for biochemical effluent of coal chemical wastewater. The device comprises a pretreatment unit, a tubular microfiltration membrane treatment unit, a chemical enhanced cleaning unit and an automatic control system. According to the advanced treatment device for the biochemical effluent of the coal chemical industry wastewater, the chemical enhanced cleaning unit is adopted, the pollution severity of the tubular membrane can be found in time through the automatic control system, and the tubular microfiltration membrane device is cleaned in real time, so that the membrane flux decay time of the tubular microfiltration membrane is greatly prolonged, the water yield of the tubular microfiltration membrane can be effectively improved, and the treatment efficiency is improved. The production efficiency is improved; and the production cost is saved.

Description

Technical Field

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

[0002] The coal chemical industry uses coal as raw material and converts it into gas, liquid, solid fuel, and chemical products through chemical processing. This industry primarily includes coal coking, coal gasification, coal gasification to ammonia, coal gasification to other products, and direct liquefaction. The wastewater generated in the coal chemical industry is a highly concentrated, difficult-to-degrade process wastewater with high chemical oxygen demand, high color, and high turbidity.

[0003] At present, coal chemical wastewater at home and abroad generally adopts the process of pretreatment + biochemical treatment + biochemical effluent deep treatment. After pretreatment and biochemical treatment to remove most of the COD, suspended solids and emulsified oil, the COD of the wastewater can be reduced to 100-300 mg / L. However, the remaining COD indicators are mainly some difficult-to-degrade polycyclic and heterocyclic organic substances with poor biodegradability. Indicators such as color, TDS, and ammonia nitrogen are still a certain distance away from the boiler reuse water indicators, and deep treatment is required to further remove pollutants such as COD and salts.

[0004] Tubular membrane filtration systems utilize tubular membrane components to directly intercept impurities in water, remove suspended solids and particulate matter, reduce turbidity, and purify water through osmosis. This reduces fouling, algae, and rust in the system, thereby purifying the water and protecting the normal operation of other system equipment. However, because coal chemical wastewater is a typical difficult-to-degrade industrial wastewater, tubular membrane filtration systems are prone to rapid flux degradation during operation, as well as frequent fouling and clogging of the membrane components, severely restricting production efficiency. Utility Model Content

[0005] The technical problem to be solved by the utility model is: how to prolong the membrane flux attenuation time of the tubular microfiltration membrane, increase the water production, and reduce the fluctuation of the water production.

[0006] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a coal chemical wastewater biochemical effluent deep treatment device.

[0007] The technical solution of this utility model:

[0008] The utility model provides a coal chemical wastewater biochemical effluent deep treatment device, comprising a pretreatment unit, a tubular microfiltration membrane treatment unit, a chemical enhanced cleaning unit and an automatic control system.

[0009] Wherein, the pretreatment unit includes a sedimentation tank and a reaction tank connected to each other, and the sedimentation tank receives the biochemical effluent of coal chemical wastewater;

[0010] The tubular microfiltration membrane treatment unit includes a tubular microfiltration membrane treatment device, a concentration tank and a water production tank. The concentration tank is connected to the reaction tank. The inlet of the tubular microfiltration membrane treatment device and the concentrated water outlet of the tubular microfiltration membrane treatment device are both connected to the concentration tank. A first valve and a delivery pump are sequentially provided on the pipeline connecting the concentrating tank and the inlet of the tubular microfiltration membrane treatment device. A second valve is provided on the pipeline connecting the concentrated water outlet of the tubular microfiltration membrane treatment device and the concentration tank. A third valve and a three-way valve are sequentially provided on the pipeline connecting the produced water outlet of the tubular microfiltration membrane treatment device and the water production tank. The other end of the three-way valve is connected to a backwash device. A pressure sensor is provided on the pipeline connecting the three-way valve and the backwash device.

[0011] The chemically enhanced cleaning unit includes a first cleaning pump, a cleaning water tank, a second cleaning pump and a reagent tank. The inlet of the tubular microfiltration membrane treatment device and the concentrated water outlet of the tubular microfiltration membrane treatment device are both connected to the cleaning water tank and the reagent tank. A first cleaning pump and a fourth valve are provided on the pipeline connecting the cleaning water tank and the inlet of the tubular microfiltration membrane treatment device, a fifth valve is provided on the pipeline connecting the concentrated water outlet of the tubular microfiltration membrane treatment device and the cleaning water tank, a second cleaning pump and a sixth valve are provided on the pipeline connecting the reagent tank and the inlet of the tubular microfiltration membrane treatment device, and a seventh valve is provided on the pipeline connecting the concentrated water outlet of the tubular microfiltration membrane treatment device and the reagent tank;

[0012] The automatic control system includes a PLC controller, an input analog signal unit and an actuator. The input analog signal unit transmits a signal to the PLC controller, and the PLC controller receives the signal to drive the actuator. The actuator includes a delivery pump, a first cleaning pump, a second cleaning pump, and first to seventh valves; the input analog signal unit includes a pressure sensor arranged on the pipeline connecting the three-way valve and the backwash device.

[0013] In some embodiments of the present invention, a diatomaceous earth dosing device, a polyaluminium chloride dosing device and a first liquid alkali dosing device are provided above the sedimentation tank.

[0014] In some embodiments of the present invention, a sodium hypochlorite dosing device, a second liquid alkali 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 invention, the first valve, the second valve, the third valve, the fourth valve, the fifth valve, the sixth valve and the seventh valve are all solenoid valves or pneumatic valves.

[0016] In some embodiments of the present invention, the backwash device includes a backwash valve, a backwash pump and a water production tank outlet valve, wherein the backwash valve is connected to the three-way valve through a pipeline, the backwash pump is connected to the backwash valve and the water production tank through a pipeline, and a water production tank outlet valve is provided on the pipeline connecting the backwash pump and the water production tank.

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

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

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

[0020] Beneficial effects of the utility model:

[0021] The utility model relates to a coal chemical wastewater biochemical effluent deep treatment device which adopts a chemical enhanced cleaning unit and can timely detect the severity of tubular membrane contamination through an automatic control system, and realize real-time cleaning of the tubular microfiltration membrane device, thereby greatly extending the membrane flux attenuation time of the tubular microfiltration membrane, effectively increasing the water production of the tubular microfiltration membrane, improving production efficiency and saving production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of a deep treatment device for biochemical effluent from coal chemical industry wastewater in Example 1;

[0023] Figure 2 This is a schematic diagram of a deep treatment device for biochemical effluent from coal chemical industry wastewater in Example 2;

[0024] The markings in the figure are as follows:

[0025] 1-sedimentation tank, 2-diatomaceous earth dosing tank, 3-polyaluminium chloride dosing tank, 4-first liquid alkali dosing tank, 5-reaction tank, 6-sodium hypochlorite dosing tank, 7-second liquid alkali dosing tank, 8-lime dosing tank, 9-sodium carbonate dosing tank, 10-concentration tank, 11-first solenoid valve, 12-delivery pump, 13-inlet of tubular microfiltration membrane treatment device, 14-tubular microfiltration membrane treatment device, 15-product water outlet of tubular microfiltration membrane device, 16-concentrated water outlet of tubular microfiltration membrane treatment device, 17 , second solenoid valve, 18-third solenoid valve, 19-three-way valve, 20-backwash valve, 21-backwash pump, 22-water production tank outlet valve, 23-water production tank, 24-seventh solenoid valve, 25-fifth solenoid valve, 26-sixth solenoid valve, 27-fourth solenoid valve, 28-first cleaning pump, 29-second cleaning pump, 30-medicine box, 31-cleaning water tank, 32-water outlet of sludge sedimentation tank, 33-sludge outlet valve, 34-sludge sedimentation tank, 35-sludge outlet of sludge sedimentation tank. DETAILED DESCRIPTION

[0026] To make the purpose, technical solutions, and technical effects of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described. The embodiments described below are part of the embodiments of the present invention, but not all of them. In combination with the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] It should be noted that relational terms such as "first" and "second" are used only 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 apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0028] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "inside", "outside", "top", "bottom", "end", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, and a specific orientation structure and operation. Therefore, they cannot be understood as limitations on the present invention.

[0029] In a specific embodiment of the present invention, the present invention provides a coal chemical wastewater biochemical effluent deep treatment device, including a pretreatment unit, a tubular microfiltration membrane treatment unit, a chemical enhanced cleaning unit and an automatic control system.

[0030] Wherein, the pretreatment unit includes a sedimentation tank and a reaction tank connected to each other, and the sedimentation tank receives the biochemical effluent of coal chemical wastewater;

[0031] The tubular microfiltration membrane treatment unit includes a tubular microfiltration membrane treatment device, a concentration tank and a water production tank. The concentration tank is connected to the reaction tank. The inlet and concentrated water outlet of the tubular microfiltration membrane treatment device are both connected to the concentration tank. A first valve and a delivery pump are sequentially provided on the pipeline connecting the concentration tank and the inlet of the tubular microfiltration membrane treatment device. A second valve is provided on the pipeline connecting the concentrated water outlet of the tubular microfiltration membrane treatment device and the concentration tank. A third valve and a three-way valve are sequentially provided on the pipeline connecting the water production tank and the water production outlet of the tubular microfiltration membrane treatment device. The other end of the three-way valve is connected to the backwash device. A pressure sensor is provided on the pipeline connecting the three-way valve and the backwash device.

[0032] The chemically enhanced cleaning unit includes a first cleaning pump, a cleaning water tank, a second cleaning pump and a reagent tank. The inlet and concentrated water outlet of the tubular microfiltration membrane treatment device are both connected to the cleaning water tank and the reagent tank. A first cleaning pump and a fourth valve are provided on the pipeline connecting the cleaning water tank and the inlet of the tubular microfiltration membrane treatment device. A fifth valve is provided on the pipeline connecting the concentrated water outlet of the tubular microfiltration membrane treatment device and the cleaning water tank. A second cleaning pump and a sixth valve are provided on the pipeline connecting the reagent tank and the inlet of the tubular microfiltration membrane treatment device. A seventh valve is provided on the pipeline connecting the concentrated water outlet of the tubular microfiltration membrane treatment device and the reagent tank.

[0033] The automatic control system includes a PLC controller, an input analog signal unit and an actuator. The input analog signal unit transmits a signal to the PLC controller, and the PLC controller receives the signal to drive the actuator. The actuator includes a delivery pump, a first cleaning pump, a second cleaning pump, and first to seventh valves; the input analog signal unit includes a pressure sensor arranged on the pipeline connecting the three-way valve and the backwash device.

[0034] The above-mentioned delivery pump, first cleaning pump, second cleaning pump, first to seventh valves and pressure sensor are electrically connected to the PCL controller. The PLC controller receives the signal from the pressure sensor and controls the opening and closing of the delivery pump, first cleaning pump, second cleaning pump, first to seventh valves by comparing with the set pressure threshold. For example, when the coal chemical wastewater biochemical effluent deep treatment device is operating normally, the delivery pump is turned on, the first to third valves are opened, and backwashing is performed regularly. When the pipeline pressure reaches 0.12MPa or above during backwashing, that is, when the pressure on the pipeline connecting the three-way valve and the backwashing device reaches 0.12MPa, chemical enhanced cleaning is started, and the PLC controls to close the delivery pump and the first to third valves, and opens the second cleaning pump, the sixth valve and the seventh valve for chemical cleaning. After the set cleaning time (for example, 60 minutes), the PLC controls to close the second cleaning pump, the sixth valve and the seventh valve, and opens the first cleaning pump, the fourth valve and the fifth valve at the same time for clean water cleaning. After the set cleaning time (for example, 60 minutes), the PLC controls to close the first cleaning pump, the fourth valve and the fifth valve, and opens the delivery pump, and the first to third valves re-enter the normal wastewater treatment process.

[0035] In some embodiments of the present invention, a diatomaceous earth dosing device, a polyaluminium chloride dosing device and a first liquid alkali dosing device are provided above the sedimentation tank.

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

[0037] In wastewater treatment, diatomaceous earth is used as a filter aid. Its fine particles form a filter layer with large pores and surface area, effectively filtering suspended solids, colloidal particles, and microorganisms, thereby improving water clarity. Its large surface area and numerous hydroxyl (OH) groups adsorb heavy metal ions, organic matter, and other pollutants in the water, fixing them to the diatomaceous earth surface through chemical reactions, thereby removing harmful substances from the water. The OH groups also regulate the pH value of the water, keeping it within a suitable range and helping to maintain water stability. Diatomaceous earth exhibits certain biological activity, adsorbing and inhibiting the growth of microorganisms such as bacteria, algae, and odor-causing substances in water, effectively improving water quality. Furthermore, the core of the tubular microfiltration membrane utilizes its high solids tolerance and abrasion resistance to separate pollutants from wastewater, and it has a broad chemical tolerance. Therefore, using a tubular microfiltration membrane treatment system to separate wastewater adsorbed by diatomaceous earth for solid-liquid separation can effectively remove heavy metal ions, organic matter, and other pollutants, while reducing wastewater hardness and COD content.

[0038] Furthermore, when diatomaceous earth is added to the sedimentation tank, a coagulant, polyaluminium chloride (PAC), and a clarifier, liquid alkali, are also added, and after sufficient reaction, they enter the reaction tank.

[0039] Sodium hypochlorite is added to the reaction tank. Its strong oxidizing properties effectively remove refractory organic matter from the wastewater and reduce its adhesion to the tubular microfiltration membrane. Lime, sodium carbonate, and liquid alkali are also added to the reaction tank. After sufficient reaction, the overflow enters the concentrating tank of the tubular microfiltration treatment unit. A first delivery pump then delivers the water from the concentrating tank to the tubular microfiltration membrane treatment unit for solid-liquid separation, further improving the removal efficiency. The concentrated water re-enters the concentrating tank from the concentrated water outlet of the tubular microfiltration membrane treatment unit. At this point, a large flow of water circulates between the concentrating tank and the tubular microfiltration membrane treatment unit, while some of the water that permeates the membrane enters the water production tank through the water production outlet of the tubular microfiltration membrane treatment unit. Finally, a pump delivers the water from the water production tank to the next step for treatment.

[0040] In some embodiments of the present invention, the backwash device includes a backwash valve, a backwash pump and a water production tank outlet valve, wherein the backwash valve is connected to the three-way valve through a pipeline, the backwash pump is connected to the backwash valve and the water production tank through a pipeline, and a water production tank outlet valve is provided on the pipeline connecting the backwash pump and the water production tank.

[0041] A tubular membrane system is a solid-liquid separation device that utilizes internal pressure-based, circulating, cross-flow filtration. The tubular membrane is tubular in shape, allowing the solid-liquid mixture to enter from the inside and the product water to seep out from the outside. The advantage of tubular membranes is that they do not require clarification; the solid-liquid mixture is directly separated by the membrane. However, solid particles often adhere to the membrane surface, requiring regular backwashing to break them up. When the water is recirculated, the broken-up sludge is flushed away. Using the product water in the product water tank as backwash water reduces both equipment investment and the use of external clean water, saving operating costs.

[0042] The following is a further description of the device for extending the flux attenuation of a tubular microfiltration membrane according to the present invention through specific embodiments.

[0043] Example 1

[0044] like Figure 1 As shown, a coal chemical wastewater biochemical effluent deep treatment device includes a pretreatment unit, a tubular microfiltration membrane treatment unit, a chemical enhanced cleaning unit and an automatic control system.

[0045] Wherein, the pretreatment unit includes a sedimentation tank 1 and a reaction tank 5 connected to each other, and the sedimentation tank 1 receives the biochemical effluent of coal chemical wastewater;

[0046] The tubular microfiltration membrane treatment unit includes a concentration tank 10, a delivery pump 12, a tubular microfiltration membrane treatment device 14 and a water production tank 23. The concentration tank 10 is connected to the reaction tank 5. One end of the delivery pump 12 is connected to the inlet 13 of the tubular microfiltration membrane treatment device, and the other end is connected to the bottom of the concentration tank 10. A first solenoid valve 11 is provided on the pipeline connecting the concentration tank 10 and the delivery pump 12. The concentrated water outlet 16 of the tubular microfiltration membrane treatment device is connected to the concentration tank 10. The tubular microfiltration membrane treatment device A second solenoid valve 17 is provided on the pipeline connecting the concentrated water outlet 16 and the concentrating tank 10, the produced water tank 23 is connected to the produced water outlet 15 of the tubular microfiltration membrane treatment device, and a third solenoid valve 18 and a three-way valve 19 are provided in sequence on the pipeline connecting the produced water outlet 15 of the tubular microfiltration membrane treatment device and the produced water tank 23. The other end of the three-way valve 19 is connected to the produced water tank 23 through a backwash valve 20, a backwash pump 21 and a produced water tank outlet valve 22 which are connected in sequence. A pressure sensor is provided on the pipeline connecting the three-way valve 18 and the backwash valve 20;

[0047] A diatomaceous earth addition tank 2, a polyaluminium chloride addition tank 3 and a first liquid alkali addition tank 4 are provided above the sedimentation tank 1;

[0048] A sodium hypochlorite dosing tank 6, a second liquid alkali dosing tank 7, a lime dosing tank 8 and a sodium carbonate dosing tank 9 are provided above the reaction tank 5;

[0049] The chemically enhanced cleaning unit includes a first cleaning pump 28, a cleaning water tank 31, a second cleaning pump 29, and a reagent tank 30. One end of the first cleaning pump 28 is connected to the cleaning water tank 31 via a pipeline, and the other end is connected to the inlet 13 of the tubular microfiltration membrane device via a pipeline. A fourth solenoid valve 27 is provided on the pipeline connecting the first cleaning pump 28 and the inlet 13 of the tubular microfiltration membrane device. The concentrated water outlet 16 of the tubular microfiltration membrane device is connected to the cleaning water tank 31 via a pipeline. A fifth solenoid valve 25 is provided on the pipeline connecting the concentrated water outlet 16 of the tubular microfiltration membrane device and the cleaning water tank 31.

[0050] One end of the second cleaning pump 29 is connected to the medicine tank 30 via a pipeline, and the other end is connected to the inlet 13 of the tubular microfiltration membrane device via a pipeline. A sixth solenoid valve 26 is provided on the pipeline connecting the second cleaning pump 29 and the inlet 13 of the tubular microfiltration membrane device. The concentrated water outlet 16 of the tubular microfiltration membrane device is connected to the medicine tank 30 via a pipeline. A seventh solenoid valve 24 is provided on the pipeline connecting the concentrated water outlet 16 of the tubular microfiltration membrane device and the medicine tank 30.

[0051] The tubular membrane in the tubular microfiltration membrane treatment device is made of polyvinylidene fluoride, and the surface pore size is 0.05 microns; the chemical enhanced cleaning agent is a mixture of sodium hypochlorite solution and liquid alkali.

[0052] The automatic control system includes a PLC controller, an input analog signal unit and an actuator. The input analog signal unit transmits a signal to the PLC controller, and the PLC controller receives the signal to drive the actuator. The actuator includes a delivery pump, a first cleaning pump, a second cleaning pump, a first solenoid valve, a second solenoid valve, a third solenoid valve, a fourth solenoid valve, a fifth solenoid valve, a sixth solenoid valve and a seventh solenoid valve; the input analog signal unit includes a pressure sensor arranged on a pipeline connecting the three-way valve 16 and the backwash valve 20, and the delivery pump, the first cleaning pump, the second cleaning pump, the first solenoid valve, the second solenoid valve, the third solenoid valve, the fourth solenoid valve, the fifth solenoid valve, the sixth solenoid valve, the seventh solenoid valve and the pressure sensor are all electrically connected to the PLC controller.

[0053] Working principle:

[0054] Turn on the PLC controller, turn off the first cleaning pump, the second cleaning pump, the fourth to the seventh solenoid valves, turn on the delivery pump 12, the first solenoid valve, the second solenoid valve and the third solenoid valve, and pass the biochemical effluent of the biochemically treated coal chemical wastewater into the sedimentation tank 1, add diatomaceous earth to the sedimentation tank 1 through the diatomaceous earth adding tank 2, and add coagulant polyaluminum chloride through the polyaluminum chloride adding tank 3 and liquid alkali through the first liquid alkali adding tank 4 to react, the effluent from the sedimentation tank 1 overflows and enters the reaction tank 5, sodium hypochlorite is added to the reaction tank 5 through the sodium hypochlorite adding tank 6, and limestone is added through the limestone adding tank 8. Lime and liquid alkali are added through the second liquid alkali adding tank 7, and sodium carbonate is added through the sodium carbonate adding tank 9 for softening treatment. The water from the reaction tank 5 overflows into the concentration tank 10 for collection, and then the water from the concentration tank 10 is sent to the tubular microfiltration membrane treatment device 14 by the delivery pump 12 for solid-liquid separation. The concentrated water re-enters the concentration tank 10 from the concentrated water outlet 16 of the tubular microfiltration membrane treatment device. At this time, a large flow of water circulates between the concentration tank 10 and the tubular microfiltration membrane treatment device 14, and part of the water that permeates the membrane enters the water production tank 23 through the water production outlet 15 of the tubular microfiltration membrane treatment device.

[0055] During the operation of the tubular microfiltration membrane treatment device, some sludge particles will adhere to the inner wall of the membrane, causing the water production of the tubular membrane to decrease. Regular backwashing is required to wash away the sludge particles accumulated on the membrane surface. The backwashing process is: stop the delivery pump 12 and close the first solenoid valve 11, close the end of the three-way valve connected to the water production tank, open the end of the three-way valve connected to the backwash valve, open the backwash valve 20, the backwash pump 21 and the water outlet valve 22 of the water production tank, and use the water produced by the tubular membrane itself to backwash the tubular membrane. After the backwash is completed, close the backwash valve 20, the backwash pump 21 and the water outlet valve 22 of the water production tank, close the end of the three-way valve connected to the backwash valve, open the end of the three-way valve connected to the water production tank, start the delivery pump 12, and open the first solenoid valve 11 to re-treat the biochemical effluent in depth.

[0056] When the tubular membrane is seriously contaminated, the pipeline pressure is relatively high during backwashing. When the pressure of the pressure sensor on the pipeline connected to the three-way valve 18 and the backwash valve 20 reaches 0.12MPa, the delivery pump 12, the first solenoid valve 11, the second solenoid valve 17 and the third solenoid valve 18 are closed, and the backwash pump 21 and the water outlet valve 22 of the production water tank are closed at the same time. The end of the three-way valve connected to the backwash valve is closed, and the end of the three-way valve connected to the production water tank is opened; the second cleaning pump is started, the sixth solenoid valve 26 and the seventh solenoid valve 24 are opened, and the tubular microfiltration membrane treatment device is started to be cleaned with a chemical, and the cleaning time is set to 60 minutes; then the second cleaning pump is stopped, the sixth solenoid valve and the seventh solenoid valve are closed, the first cleaning pump 28 is started, the fourth solenoid valve 27 and the fifth solenoid valve 25 are opened, and the tubular microfiltration membrane treatment device is started to be cleaned with clean water, and the cleaning time is set to 60 minutes. After cleaning is completed, stop the first cleaning pump 28, close the fourth solenoid valve 27 and the fifth solenoid valve 25, open the delivery pump 12, the first solenoid valve 11, the second solenoid valve 17 and the third solenoid valve 18, and continue to deeply treat the biochemical effluent of the coal chemical wastewater.

[0057] Example 2

[0058] like Figure 2 As shown, a device for deep treatment of biochemical effluent from coal chemical industry wastewater is different from Example 1 in that:

[0059] The device also includes a sludge sedimentation tank 34, which is connected to the bottom of the thickening tank 10. A sludge outlet valve 33 is provided on the pipeline connecting the sludge sedimentation tank 34 and the thickening tank 10. The sludge sedimentation tank 34 is provided with a water outlet 32 ​​and a sludge outlet 35 of the sludge sedimentation tank.

[0060] Working principle:

[0061] When the sludge in the thickening tank is large, the sludge outlet valve 33 is opened, and the mud-water mixture at the bottom of the thickening tank enters the sludge sedimentation tank 34. After static separation, the sludge at the bottom is sent to the plate and frame filter press for dehydration through the sludge outlet 35 of the sludge sedimentation tank, and the upper clear water of the sludge sedimentation tank 34 is returned to the sedimentation tank 1 through the water outlet 32 ​​of the sludge sedimentation tank.

[0062] Experimental Example 1

[0063] The biochemical effluent of coal chemical wastewater was treated using the device of Example 1. In the experimental group, the amount of diatomaceous earth added was 250 mg / L, the amount of polyaluminum chloride added was 100 mg / L, and the amount of the first liquid alkali added was 30 mg / L; the amount of sodium hypochlorite added (effective concentration) was 100 mg / L, the amount of sodium carbonate added was 100 mg / L, the amount of lime added was 250 mg / L, and the amount of the second liquid alkali added was 300 mg / L. During the treatment process, the chemical enhanced cleaning unit was turned on for real-time cleaning;

[0064] The control group 1 did not use the chemical enhanced cleaning unit for cleaning, and the membrane flux of the tubular microfiltration membrane of the experimental group and the control group were recorded from 120m 3 / h attenuates to 60m 3 / h time.

[0065] The experimental results are shown in Table 1:

[0066] Table 1 Treatment results of the experimental group and the control group

[0067] Experimental group Control group 1 <![CDATA[The membrane flux decays from 120 m 3 / h to 60 m 3 / h within a certain time]]> 120h 30h

[0068] As shown in Table 1, the use of chemically enhanced cleaning units and automatic control systems can promptly detect the severity of tubular membrane contamination and perform real-time cleaning, which greatly prolongs the membrane flux decay time of the tubular microfiltration membrane, effectively increases the water production of the tubular microfiltration membrane, improves production efficiency, and saves production costs.

[0069] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A coal chemical wastewater biochemical effluent deep treatment device, characterized in that: It includes pretreatment unit, tubular microfiltration membrane treatment unit, chemical enhanced cleaning unit and automatic control system. Wherein, the pretreatment unit includes a sedimentation tank and a reaction tank connected to each other, and the sedimentation tank receives the biochemical effluent of coal chemical wastewater; The tubular microfiltration membrane treatment unit includes a tubular microfiltration membrane treatment device, a concentration tank and a water production tank. The concentration tank is connected to the reaction tank. The inlet of the tubular microfiltration membrane treatment device and the concentrated water outlet of the tubular microfiltration membrane treatment device are both connected to the concentration tank. A first valve and a delivery pump are sequentially provided on the pipeline connecting the concentrating tank and the inlet of the tubular microfiltration membrane treatment device. A second valve is provided on the pipeline connecting the concentrated water outlet of the tubular microfiltration membrane treatment device and the concentration tank. A third valve and a three-way valve are sequentially provided on the pipeline connecting the produced water outlet of the tubular microfiltration membrane treatment device and the water production tank. The other end of the three-way valve is connected to a backwash device. A pressure sensor is provided on the pipeline connecting the three-way valve and the backwash device. The chemically enhanced cleaning unit includes a first cleaning pump, a cleaning water tank, a second cleaning pump and a reagent tank. The inlet of the tubular microfiltration membrane treatment device and the concentrated water outlet of the tubular microfiltration membrane treatment device are both connected to the cleaning water tank and the reagent tank. A first cleaning pump and a fourth valve are provided on the pipeline connecting the cleaning water tank and the inlet of the tubular microfiltration membrane treatment device, a fifth valve is provided on the pipeline connecting the concentrated water outlet of the tubular microfiltration membrane treatment device and the cleaning water tank, a second cleaning pump and a sixth valve are provided on the pipeline connecting the reagent tank and the inlet of the tubular microfiltration membrane treatment device, and a seventh valve is provided on the pipeline connecting the concentrated water outlet of the tubular microfiltration membrane treatment device and the reagent tank; The automatic control system includes a PLC controller, an input analog signal unit and an actuator. The input analog signal unit transmits the signal to the PLC controller, and the PLC controller receives the signal to drive the actuator. The delivery pump, the first cleaning pump, the second cleaning pump and the first to seventh valves are used as actuators. The input analog signal unit includes a pressure sensor provided on the pipeline connecting the three-way valve and the backwash device.

2. The device according to claim 1, characterized in that A diatomaceous earth dosing device, a polyaluminium chloride dosing device and a first liquid alkali dosing device are arranged above the sedimentation tank.

3. The device according to claim 1, characterized in that A sodium hypochlorite dosing device, a second liquid alkali dosing device, a lime dosing device and a sodium carbonate dosing device are arranged above the reaction tank.

4. The device according to any one of claims 1 to 3, characterized in that The first valve, the second valve, the third valve, the fourth valve, the fifth valve, the sixth valve and the seventh valve are solenoid valves and / or pneumatic valves.

5. The device according to any one of claims 1 to 3, characterized in that The backwash device includes a backwash valve, a backwash pump and a water production tank outlet valve, wherein the backwash valve is connected to the three-way valve through a pipeline, the backwash pump is connected to the backwash valve and the water production tank through a pipeline, and the water production tank outlet valve is provided on the pipeline connecting the backwash pump and the water production tank.

6. The device according to claim 4, characterized in that The backwash device includes a backwash valve, a backwash pump and a water production tank outlet valve, wherein the backwash valve is connected to the three-way valve through a pipeline, the backwash pump is connected to the backwash valve and the water production tank through a pipeline, and the water production tank outlet valve is provided on the pipeline connecting the backwash pump and the water production tank.

7. The device according to any one of claims 1 to 3, characterized in that The pretreatment unit further comprises a sludge sedimentation tank, which is connected to the concentration tank.

8. The device according to claim 5, characterized in that The pretreatment unit further comprises a sludge sedimentation tank, which is connected to the concentration tank.

9. The device according to any one of claims 1 to 3, characterized in that The membrane material of the tubular microfiltration membrane treatment device is polyethylene and / or polyvinylidene fluoride.

10. The device according to any one of claims 1 to 3, characterized in that The surface pore size of the membrane material of the tubular microfiltration membrane treatment device is 0.01-1 micron.

Images