CN107176718A - The apparatus and method that a kind of embrane method handles agricultural chemicals waste water - Google Patents

Abstract

A device for treating pesticide wastewater by membrane method, comprising a coagulation sedimentation tank, an ultrafiltration device, a reverse osmosis device, a reverse osmosis concentrated water tank, and a nanofiltration device, characterized in that the coagulation sedimentation tank (1) has a conical steel structure Barrel, the raw water tank (2) is a box, the ultrafiltration device (5) is connected with the raw water tank through the raw water booster pump (3), the intermediate water tank (6) is a box, the Reverse osmosis device (8) is provided with reverse osmosis membrane, and described reverse osmosis concentrated water tank (11) is a casing, and the bottom of casing is connected with nanofiltration device (13) bottom by nanofiltration high-pressure pump (12); The filtering device is provided with a nanofiltration membrane, and the top of the sludge storage tank (15) is connected with the bottom of the coagulation sedimentation tank. The invention has the advantages of simple device structure, convenient manufacture, average removal rate of COD _Cr and TOC up to 90%, reduction of waste liquid over 70%, skid-mounted integrated equipment and convenient transportation and installation.

Description

Device and method for treating pesticide wastewater by membrane method

technical field

The invention relates to an industrial wastewater treatment device, in particular to a device and method for treating pesticide wastewater by membrane method.

Background technique

Entering the 21st century, with the rapid development of industrialization level, the amount of wastewater produced in our country is increasing day by day. In particular, pesticide wastewater has high concentration of organic matter, complex components, and contains harmful and toxic substances to the environment and human body. In addition, in recent years, my country has paid more and more attention to the environment. The standards have increased the difficulty for the treatment of these pesticide hazardous wastewater. Therefore, how to deal with it reasonably and reduce the cost of the enterprise to win the maximum profit is one of the problems being explored in today's society.

Pesticide wastewater refers to the wastewater discharged from pesticide factories in the process of pesticide production. The quality and quantity of wastewater are unstable. It is mainly divided into benzene-containing wastewater, organic phosphorus-containing wastewater, high-concentration saline-containing wastewater, high-concentration phenol-containing wastewater, and mercury-containing wastewater. There are many kinds of pesticides, and the water quality of pesticide wastewater is complex. Its main feature is that the concentration of pollutants is high, and COD (chemical oxygen demand) can reach tens of thousands of milligrams per liter; the toxicity is high. In addition to pesticides and intermediates, wastewater also contains phenols, Toxic substances such as arsenic and mercury, as well as many substances that are difficult to biodegrade; there is a foul smell, which is irritating to human respiratory tract and mucous membranes; the water quality and quantity are unstable. Therefore, the pollution of pesticide wastewater to the environment is very serious. The purpose of pesticide wastewater treatment is to reduce the concentration of pollutants in pesticide production wastewater, improve the recycling rate, and strive to achieve harmlessness, but the treatment technology is not yet perfect.

On the other hand, currently the main method for treating pesticide wastewater is incineration, which has the advantages of being simple and easy to implement, but it also has many problems. The biggest problem is the waste of resources, because most hazardous wastewater contains a lot of water, which can be reduced by secondary treatment. In recent years, the development of membrane technology has become more and more mature. It has the advantages of simple operation, small footprint, and high degree of automation. The most important thing is that it can concentrate wastewater, which just achieves the effect of reduction.

Membrane treatment technologies generally include ultrafiltration, nanofiltration, and reverse osmosis. The membrane materials are different, and the membrane pore size gradually decreases, which can separate smaller substances. At present, pretreatment is required before the membrane system, which has reduced the damage to the membrane caused by sewage. However, at present, this process is mostly used in drinking water, domestic sewage, low-concentration industrial wastewater, pesticide wastewater, and there are relatively few research reports on wastewater with high COD content. Due to the high water content of some pesticide wastewater, if all of them are treated as hazardous wastewater, it will cause a serious waste of resources, and the transfer of these wastewater will increase operating costs and dramatically increase costs.

Therefore, there are above-mentioned inconveniences and problems in the known pesticide wastewater treatment methods.

Contents of the invention

The object of the present invention is to propose a device for treating pesticide wastewater by membrane method with high efficiency, simple operation and low operating cost.

Another object of the present invention is to propose a device for treating pesticide wastewater by membrane method for wastewater reduction.

Another object of the present invention is to propose a treatment method for a device for treating pesticide wastewater by membrane method with high efficiency, simple operation and low operation cost.

Another object of the present invention is to propose a treatment method for a device for treating pesticide wastewater by membrane method for wastewater reduction.

For realizing the above object, technical solution of the present invention is:

A device for treating pesticide wastewater by membrane method. The pesticide wastewater contains cleaning wastewater in pesticide production. The cleaning wastewater includes thickeners, dispersants, and pyraclostrobin pesticide active ingredients, including coagulation sedimentation tanks, raw water tanks, ultrafiltration device, intermediate water tank, reverse osmosis device, reverse osmosis concentrated water tank, nanofiltration device, final concentrated water tank, sludge storage tank, sludge dewatering device, characterized in that:

The conical steel structure barrel of the coagulation sedimentation tank has a stirrer on the top of the barrel, and the frequency range of the stirrer is 0-50HZ, so as to control the speed of the stirrer, and add coagulation and flocculation agents along with the stirrer;

The raw water tank is a box body, the box body is connected with the middle part of the coagulation sedimentation tank, and the supernatant in the coagulation sedimentation tank is discharged to the raw water tank; the bottom of the raw water tank is connected with the raw water booster pump;

The ultrafiltration device is connected to the raw water tank through a raw water booster pump, and the raw water in the raw water tank enters the ultrafiltration device through a security filter; the ultrafiltration device is provided with a filter membrane, which adopts a hollow fiber membrane and uses a polypropylene PP filter element or Polyvinylidene fluoride PVDF filter element;

The middle water tank is a box body, the top of the middle water tank is connected with the ultrafiltration device to receive ultrafiltered water; the bottom of the middle water tank is connected with the inlet end of the reverse osmosis high pressure pump;

The reverse osmosis device is provided with a reverse osmosis membrane, the bottom of the reverse osmosis device is connected with the outlet end of the reverse osmosis high-pressure pump, and the top of the reverse osmosis device is connected with a qualified water tank; Antiscalants and fungicides;

The reverse osmosis concentrated water tank is a box body, the top of the box body is connected to the middle water tank, and the bypass of the connecting pipeline is connected to the trolley cleaning device, and the bottom end of the box body is connected to the nanofiltration device through the nanofiltration high-pressure pump. The bottom is connected; the nanofiltration device is equipped with a nanofiltration membrane, and the top of the nanofiltration device is connected to the final concentrated water tank through a pipeline;

The top of the sludge storage tank is connected to the bottom of the coagulation sedimentation tank, and the bypass of the connecting pipeline is connected to the cleaning device. The bottom of the sludge storage tank is connected to the sludge dewatering device through a sludge pump, and the sludge The dehydration device is connected with the filtrate storage device.

The device for treating pesticide wastewater by membrane method of the present invention can also be further realized by adopting the following technical measures.

The aforementioned device for treating pesticide wastewater by membrane method, wherein the coagulation agent includes sodium hydroxide, polyaluminum chloride, and polyferric chloride.

The aforementioned device for treating pesticide wastewater by membrane method, wherein the flocculant includes polyacrylamide, chitosan and organic polymer flocculant.

The aforementioned device for treating pesticide wastewater by membrane method, wherein the filtration accuracy of the polypropylene PP filter element is 1-10 μm.

The aforementioned device for treating pesticide wastewater by membrane method, wherein the reverse osmosis membrane is equipped with an aromatic polyamide spiral-wound composite membrane with an average membrane flux of 30-58 L/h/m ² and connected in series.

The aforementioned device for treating pesticide wastewater by membrane method, wherein the nanofiltration membranes have an average membrane flux of 10-27 L/h/m ² and are connected in parallel;

The aforementioned membrane method for treating pesticide wastewater, wherein the cleaning device is a trolley-type cleaning device that can be moved by wheels, the cleaning device is equipped with a cleaning agent, and the cleaning device is provided with a quick connector that can be connected with a reverse osmosis device and a nanofiltration device. Correspondingly set joints are quickly connected, and the nanofiltration membrane or reverse osmosis membrane is cleaned; the cleaning device is equipped with a separate security filter, cleaning pump, cleaning agent preparation tank, and a constant temperature device.

The aforementioned device for treating pesticide wastewater by membrane method, wherein the cleaning agent is sodium hydroxide and citric acid;

The aforementioned device for treating pesticide wastewater by membrane method, wherein the device for treating pesticide wastewater is an integrated device, and all unit devices including coagulation sedimentation tank, ultrafiltration device, reverse osmosis device, and nanofiltration device are integrated and densely installed in a box in vivo.

The aforementioned device for treating pesticide wastewater by membrane method, wherein the box body is a container.

The aforementioned device for treating pesticide wastewater by membrane method is characterized in that the device for treating pesticide wastewater is a skid-mounted device, which is convenient for transportation and installation.

A treatment method of a device for treating pesticide wastewater by membrane method, characterized in that it comprises the following steps:

a. The waste water is flocculated and settled into the raw water tank to remove larger solid suspended matter through the security filter

Put the pesticide wastewater in the ton barrel into the coagulation sedimentation tank to the scale line through the water pump, put a certain amount of configured polyaluminum chloride solution into the coagulation sedimentation tank; add a certain amount of configured flocculant polyacrylamide with the agitator Solution, settling for 2-24 hours, drain the clear supernatant of the coagulation sedimentation tank to the original water tank;

b. The colloids and suspended matter in the waste water are treated by the ultrafiltration device and enter the intermediate water tank

Check the security filter, under the action of pressure, make the waste water pass through the security filter, the ultrafiltration membrane and the water tank pipeline valve, turn on the booster pump of the raw water tank, and enter the water production mode; cleaning;

c. The waste water is discharged up to the standard after the reverse osmosis treatment device produces water

Check the opening status of the pipeline valves of the nanofiltration and reverse osmosis devices, turn on the reverse osmosis high-pressure pump and the nanofiltration high-pressure pump, adjust the frequency of the high-pressure pump, and the flow rate of the produced water/concentrated water, enter the water production state, and turn off the high pressure after the water production is completed Pumps, water inlet and outlet valves; if necessary, perform membrane cleaning; prepare cleaning solution in the cleaning bucket, and check the opening status of the cleaning bucket-high pressure pump-nanofiltration and reverse osmosis pipeline valves. Turn on the nanofiltration high-pressure pump and reverse osmosis high-pressure pump for circular cleaning;

d. Sludge discharge from flocculation sedimentation tank

Check the opening status of the pipeline valve of the sludge system, turn on the sludge pump, pump the sludge from the flocculation sedimentation tank into the sludge storage tank, turn on the sludge pump and the sludge dewatering device, discharge part of the sludge, and dehydrate the other part Enter the filtrate collection device and pour into the flocculation sedimentation tank together with the waste water, and then carry out the waste water circulation treatment.

The treatment method of the device for treating pesticide wastewater by membrane method of the present invention can also be further realized by adopting the following technical measures.

The aforementioned method, wherein the concentration of the polyaluminum chloride solution is 20%.

The aforementioned method, wherein the concentration of the polyacrylamide solution is 1 mg/L.

The aforementioned method, wherein the filter pore diameter of the security filter is in the range of 0.5-120 μm.

The aforementioned method, wherein the pore size of the ultrafiltration membrane is 0.2um.

The aforementioned method, wherein the ultrafiltration membrane cleaning is prepared in a cleaning agent preparation barrel with a cleaning solution, first using a concentration of 0.1% NaOH, adding a cleaning solution of 0.025% sodium dodecylbenzenesulfonate for alkali cleaning, and then using a concentration of Pickling with 3% citric acid; the cleaning pressure is 0.4MPa, the cleaning time is 30min, and the cleaning temperature is 25°C. Check that the booster pump and the valve of the cleaning pipeline of the ultrafiltration device are open, and start the cleaning pump to perform ultrafiltration Membrane backwashing.

The aforementioned method, wherein the treatment method of the device for treating pesticide wastewater by the membrane method is applicable to the treatment of wastewater produced in the chemical industry or other hazardous wastewater.

After adopting the above-mentioned technical scheme, the device and method for treating pesticide wastewater by membrane method of the present invention have the following advantages:

1. The structure of the device is simple, easy to manufacture, small in size, low in cost, and high in automation;

2. Membrane treatment has a remarkable effect and can completely remove suspended solids. The average removal rate of COD _Cr , TOC and active components reaches 90%. The produced water can fully guarantee that it meets the relevant national discharge standards, and can even be reused in production;

3. Skid-mounted integrated equipment, the processing system is integrated in the container, which is convenient for transportation and installation.

4. The device is an economical and efficient waste liquid treatment equipment with broad application prospects.

Description of drawings

Fig. 1 is the block diagram of the technological process of the device of the membrane method treatment pesticide wastewater of the embodiment of the present invention;

Fig. 2 is a schematic diagram of equipment layout of a device for treating pesticide wastewater by membrane method according to an embodiment of the present invention.

In the figure: 1 coagulation sedimentation tank, 2 raw water tank, 3 raw water booster pump, 4 security filter, 5 ultrafiltration device, 6 intermediate water tank, 7 reverse osmosis high pressure pump, 8 reverse osmosis device, 9 qualified water tank, 10 small Cart cleaning device, 11 reverse osmosis concentrated water tank, 12 nanofiltration high-pressure pump, 13 nanofiltration device, 14 final concentrated water tank, 15 sludge storage tank, 16 sludge pump, 17 sludge dehydration device, 18 filtrate storage device.

detailed description

The present invention will be further described below in conjunction with embodiment and accompanying drawing.

Example 1

The device for treating pesticide wastewater by membrane method of the present invention comprises a coagulation sedimentation tank 1, a raw water tank 2, an ultrafiltration device 5, an intermediate water tank 6, a reverse osmosis device 8, a reverse osmosis concentrated water tank 11, a nanofiltration device 13, and a final concentrated water tank 14. Sludge storage water tank 15, sludge dehydration device 17.

Fig. 1 is a process flow diagram of a device for treating pesticide wastewater by membrane method according to an embodiment of the present invention. The coagulation-sedimentation tank has a conical steel structure barrel body, the top of the barrel body is provided with an agitator, the frequency range of the agitator is 0-50HZ, to control the speed of the agitator, and add coagulation agent and flocculation agent along with the agitator; Coagulants include sodium hydroxide, polyaluminum chloride, and polyferric chloride. The flocculating agents include polyacrylamide, chitosan and organic polymer flocculants.

The raw water tank 2 is a box body, the box body is connected with the middle part of the coagulation sedimentation tank, and the supernatant in the coagulation sedimentation tank is discharged to the raw water tank; the bottom of the raw water tank is connected with the raw water booster pump 3;

Described ultrafiltration device 5 is connected with raw water tank 2 by raw water booster pump 3, and the raw water of raw water tank enters ultrafiltration device through security filter 4; Ultrafiltration device is provided with filter membrane, and filter membrane adopts hollow fiber membrane, uses poly A propylene PP filter element or a polyvinylidene fluoride PVDF filter element; the filtration accuracy of the polypropylene PP filter element is 1-10 μm.

The middle water tank 6 is a casing, the top of the middle water tank is connected with the ultrafiltration device, and accepts ultrafiltered water; the bottom of the middle water tank is connected with the inlet end of the reverse osmosis high pressure pump 7;

The reverse osmosis device 8 is provided with a reverse osmosis membrane, the bottom of the reverse osmosis device is connected with the outlet end of the reverse osmosis high-pressure pump 7, and the top of the reverse osmosis device is connected with the qualified water tank 9; Antiscalants and fungicides are added to the pump; the reverse osmosis membrane is equipped with an aromatic polyamide spiral-wound composite membrane with an average membrane flux of 30-58L/h/m ² and is connected in series.

The reverse osmosis concentrated water tank 11 is a box body, the top of the box body is connected with the middle water tank, and the bypass of the connecting pipeline is connected with the trolley cleaning device 10, and the bottom end of the box body is connected with the nanofiltration high-pressure pump 12 and The bottom of the nanofiltration device 13 is connected; the nanofiltration device is provided with a nanofiltration membrane, and the top of the nanofiltration device is connected to the final concentrated water tank 14 through a pipeline; the average membrane flux of the nanofiltration membrane is 10-27L/h/m ² , using connected in parallel;

The top of the sludge storage tank 15 is connected to the bottom of the coagulation sedimentation tank 1, and the bypass of the connection pipeline is connected with the trolley cleaning device 10, and the bottom of the sludge storage tank 15 is connected with the sludge pump 16 and The sludge dewatering device 17 is connected, and the sludge dewatering device is connected with the filtrate storage device 18 .

Example 2

The processing method of the device for treating pesticide wastewater by membrane method of the present invention comprises the following steps:

a. Put the waste water in the ton barrel, the waste water containing the cleaning waste liquid in the production of pesticides, including thickener, dispersant and pyraclostrobin and other active ingredients of pesticides, into the coagulation sedimentation tank to the scale line through the water pump, and then add Sodium hydroxide makes the pH reach 8-11, and then add a certain amount of configured polychlorinated (PAC) solution, 20% concentration of PAC solution, the dosage is 1000-8000mg/L. Turn on the stirrer, stir at 60-100 rpm, stir for 10-20 minutes, stop stirring; put in a certain amount of prepared polyacrylamide (PAM) solution, the concentration of PAM is 1mg/L, and the concentration of dosing is 1-10mg/L L. Turn on the mixer, stir at a rate of 20-50 rpm, stir for 3-5 minutes, and stop stirring; at this time, the waste water alum flower gradually forms and grows, and settles for 2-24 hours; discharge the clear supernatant of the coagulation sedimentation tank to the original water tank.

b. Check the security filter. The security filter adopts a formed filter material. Under the action of pressure, the raw liquid passes through the filter material, and the filter residue stays on the pipe wall, and the filtrate flows out through the filter material, so as to achieve the purpose of filtration. Security filter structure: filter cloth, filter screen, filter sheet, sintered filter tube, wire wound filter element, meltblown filter element, etc. Due to the different filter materials, the filter pore size is also different. Precision filtration is a kind of filtration between sand filtration (coarse filtration) and ultrafiltration, and the selected filter pore size is generally in the range of 0.5 to 120 μm. The ultrafiltration membrane is made of PP material, with a pore size of 0.2um and a hollow fiber membrane structure, so that the valve of the water tank pipeline is opened; the booster pump of the raw water tank is turned on, the flow rate of the produced water/concentrated water is adjusted, and the produced water enters through the valve and flowmeter model. After the water production is over, if necessary, membrane cleaning is required; prepare a cleaning solution in the cleaning bucket, and first use a cleaning solution with a concentration of 0.1% NaOH + 0.025% sodium dodecylbenzenesulfonate for alkaline cleaning (pH=11-12) , and then use 3% citric acid for pickling (pH=3-4), the cleaning pressure is 0.4MPa, the cleaning time is 30min, and the cleaning temperature is 25°C. Check that the booster pump and the cleaning pipeline valve of the ultrafiltration device are in the open state, and start the cleaning pump to backwash the ultrafiltration membrane.

c. Check the opening status of the pipeline valves of nanofiltration and reverse osmosis devices; turn on the reverse osmosis high-pressure pump and nanofiltration high-pressure pump, adjust the frequency of the high-pressure pump and the flow rate of produced water/concentrated water, and enter the water-producing state. After the water production is finished, close the high-pressure pump and the water inlet and outlet valves; if necessary, clean the nanofiltration membrane; prepare the cleaning solution in the cleaning bucket, and check the valve opening status of the cleaning bucket-high-pressure pump-nanofiltration and reverse osmosis pipelines. Turn on the nanofiltration high-pressure pump and the reverse osmosis high-pressure pump for circular cleaning.

d. Check the opening status of the pipeline valve of the sludge system, turn on the sludge pump, pour the sludge from the flocculation sedimentation tank into the sludge storage tank, turn on the sludge pump and the sludge dehydration device, discharge the sludge, and enter the sludge dehydration tank The filtrate collection device is pumped into the flocculation sedimentation tank together with the new wastewater for recycling treatment.

Example 3

A pesticide factory has about 250 tons of pesticide wastewater every year. Wastewater quality (average): CODCr is 16500mg/L, TOC is 4537mg/L, conductivity is 654.4μS/cm, pH is 6.48, and the mass concentration of suspended solids (SS) is about 6000mg/L. See Table 1 for the effluent water quality after the process treatment of Example 2.

Table 1 Water Quality of Pesticide Plant Wastewater After Treatment

One ton of raw water entering the system can produce 7000 kg of qualified water, 2600 kg of concentrated waste liquid and 400 kg of sludge.

Example 4

A chemical paint manufacturer produces water-based paints for automobile painting. The influent COD of its production wastewater is 9340mg/L, and the SS is 4500. After the process of Example 2, the effluent COD and SS all meet the emission standards. See Table 2 for the effluent water quality after the process treatment of Example 2.

Table 2 Water quality of effluent from chemical coating factory after treatment

Example 5

Wastewater from a pesticide factory contains active ingredients pendimethalin, kresoxim-methyl, difenoconazole, dimethyltetrachloride, and difenoconazole. If it enters the water, it will cause serious environmental problems and indirectly affect human health. The company stipulates The discharge standards are respectively less than 0.20, 2.20, 6.8, 0.063, 1.91. After the process of embodiment 2, the influent and effluent water quality is shown in Table 3, and the removal rate of various coagulums can reach more than 99%.

Table 3 The effluent water quality of another pesticide factory after treatment

After running stably for about a month, there is no significant difference in the pressure difference of the membrane system. The reverse osmosis product water flow rate is 500L/h, and the product water meets the discharge standard.

The present invention has substantive features and significant technical progress. The device and method for treating pesticide wastewater by membrane method of the present invention adopts a skid-mounted device, which has a simple structure, a small footprint, low cost, and a high degree of automation. The process treatment effect is remarkable. After treatment, all suspended solids can be removed; the average removal rate of COD _Cr , TOC and active components can reach more than 90% and meet the national emission standards. The invention can realize the reduction of waste water technically, has good economic benefits, has broad application prospects, and is an economical and efficient waste water treatment equipment.

The above embodiments are only for illustrating the present invention, rather than limiting the present invention. Those skilled in the relevant technical field can also make various transformations or changes without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions should also belong to the category of the present invention and should be defined by each claim.

Claims (10)

1. A device for treating pesticide wastewater by membrane method. The pesticide wastewater contains cleaning wastewater in pesticide production. The cleaning wastewater includes a thickener, a dispersant and pyraclostrobin pesticide active ingredients, including a coagulation sedimentation tank (1), Raw water tank (2), ultrafiltration device (5), intermediate water tank (6), reverse osmosis device (8), reverse osmosis concentrated water tank (11), nanofiltration device (13), final concentrated water tank (14), sludge Storage tank (15), sludge dewatering device (17), is characterized in that: The coagulation-sedimentation tank (1) has a conical steel structure barrel, and an agitator is arranged on the top of the barrel, and the frequency range of the agitator is 0-50HZ, so as to control the speed of the agitator, and add coagulation and flocculation agents along with the agitator; The raw water tank (2) is a box body, the box body communicates with the middle part of the coagulation sedimentation tank, and the supernatant in the coagulation sedimentation tank is discharged to the raw water tank; the bottom of the raw water tank is connected with the raw water booster pump (3); Described ultrafiltration device (5) is connected with raw water tank (2) by raw water booster pump (3), and the raw water of raw water tank enters ultrafiltration device through security filter (4); Ultrafiltration device is provided with filter membrane, filters The membrane adopts hollow fiber membrane, using polypropylene PP filter element or polyvinylidene fluoride PVDF filter element; The middle water tank (6) is a casing, the top of the middle water tank is connected with the ultrafiltration device, and accepts ultrafiltered water; the bottom of the middle water tank is connected with the inlet end of the reverse osmosis high-pressure pump (7); The reverse osmosis device (8) is provided with a reverse osmosis membrane, the bottom of the reverse osmosis device is connected with the outlet end of the reverse osmosis high-pressure pump (7), and the top of the reverse osmosis device is connected with a qualified water tank (9); system, adding antiscalant and fungicide through the pump of the dosing system; The reverse osmosis concentrated water tank (11) is a box body, the top of the box body is connected with the middle water tank, and the bypass of the connecting pipeline is connected with the trolley cleaning device (10), and the bottom end of the box body is passed through nanofiltration The high-pressure pump (12) is connected to the bottom of the nanofiltration device (13); the nanofiltration device is provided with a nanofiltration membrane, and the top of the nanofiltration device is connected to the final concentrated water tank (14) through a pipeline; The top of the sludge storage tank (15) is connected to the bottom of the coagulation sedimentation tank (1), and the bypass of the connecting pipeline is connected to the cleaning device, and the bottom of the sludge storage tank (15) is passed through the sludge pump. (16) is connected with the sludge dewatering device (17), and the sludge dewatering device is connected with the filtrate storage device (18). 2. The device for treating pesticide wastewater by membrane method as claimed in claim 1, wherein the coagulation agent comprises sodium hydroxide, polyaluminum chloride, and polyferric chloride. 3. The device for treating pesticide wastewater by membrane method as claimed in claim 1, wherein the flocculating agent comprises polyacrylamide, chitosan and organic polymer flocculants. 4 . The device for treating pesticide wastewater by membrane method according to claim 1 , wherein the nanofiltration membranes have an average membrane flux of 10-27 L/h/m ² and are connected in parallel. 5. the device of membrane process pesticide wastewater treatment as claimed in claim 1, is characterized in that, described cleaning device (10) is a trolley type cleaning device, can move by wheel, and cleaning device is housed cleaning agent, and cleaning device There are quick connectors that can be quickly connected to the corresponding joints of the reverse osmosis device (8) and nanofiltration device (13), and clean the nanofiltration membrane or reverse osmosis membrane; the cleaning device is equipped with a separate security filter and cleaning pump , cleaning agent preparation barrel, constant temperature device. 6. The device for treating pesticide wastewater by membrane method according to claim 1, characterized in that, the device for treating pesticide wastewater is a skid-mounted device, which is convenient for transportation and installation. 7. a treatment method of a device for treating pesticide wastewater by membrane method as claimed in claim 1, characterized in that it may further comprise the steps: a. The waste water is flocculated and settled into the raw water tank to remove larger solid suspended matter through the security filter Put the pesticide wastewater in the ton barrel into the coagulation sedimentation tank to the scale line through the water pump, put a certain amount of configured polyaluminum chloride solution into the coagulation sedimentation tank; add a certain amount of configured flocculant polyacrylamide with the agitator Solution, settling for 2-24 hours, drain the clear supernatant of the coagulation sedimentation tank to the original water tank; b. The colloids and suspended matter in the waste water are treated by the ultrafiltration device and enter the intermediate water tank Check the security filter, under the action of pressure, make the waste water pass through the security filter, the ultrafiltration membrane and the water tank pipeline valve, turn on the booster pump of the raw water tank, and enter the water production mode; cleaning; c. The waste water is discharged up to the standard after the reverse osmosis treatment device produces water Check the opening status of the pipeline valves of the nanofiltration and reverse osmosis devices, turn on the reverse osmosis high-pressure pump and nanofiltration high-pressure pump, adjust the frequency of the high-pressure pump, and the flow rate of produced water/concentrated water, enter the water production state, and turn off the high pressure after the water production is completed Pumps, water inlet and outlet valves; if necessary, perform membrane cleaning; prepare cleaning solution in the cleaning bucket, and check the opening status of the cleaning bucket-high pressure pump-nanofiltration and reverse osmosis pipeline valves. Turn on the nanofiltration high-pressure pump and reverse osmosis high-pressure pump for circular cleaning; d. Sludge discharge from flocculation sedimentation tank Check the opening status of the pipeline valve of the sludge system, turn on the sludge pump, pump the sludge from the flocculation sedimentation tank into the sludge storage tank, turn on the sludge pump and the sludge dehydration device, discharge part of the sludge, and dehydrate the other part Enter the filtrate collection device and pour it into the flocculation sedimentation tank together with the waste water, and then carry out the waste water circulation treatment; Among them: the amount of sodium hydroxide added in the coagulation agent needs to make the pH of the sedimentation tank treatment liquid be 10. 8. The treatment method of the device for treating pesticide wastewater by membrane method as claimed in claim 7, wherein the concentration of the polyaluminum chloride solution is 20%. 9. the processing method of the device of membrane process pesticide wastewater treatment as claimed in claim 7, is characterized in that, the processing method of the device of described membrane process pesticide wastewater makes the average removal rate of COD _Cr , TOC reach more than 90%, Meet the national emission standards. 10. The treatment method of the device for treating pesticide wastewater by membrane method as claimed in claim 7, characterized in that, the treatment method of the device for treating pesticide wastewater by membrane method makes waste liquid reduction reach more than 70%.