WO2022021952A1

WO2022021952A1 - Mbr flat filter membrane for domestic sewage treatment and preparation method therefor

Info

Publication number: WO2022021952A1
Application number: PCT/CN2021/088080
Authority: WO
Inventors: 程跃; 龚喜龙; 邱长泉; 庄志; 虞少波
Original assignee: 上海恩捷新材料科技有限公司
Priority date: 2020-07-27
Filing date: 2021-04-19
Publication date: 2022-02-03
Also published as: CN111804151B; CN111804151A

Abstract

Disclosed is a preparation method for an MBR flat filter membrane for domestic sewage treatment. The method comprises the following steps: modification of nanoparticles, preparation of a polyethylene membrane-casting solution, preparation of a polyethylene flat membrane, amino acid modification, and preparation of the MBR flat filter membrane. The chemical stability of the membrane is improved by using the advantages of polyethylene such as high air permeability, high crystallinity, good chemical stability, and corrosion resistance to most acids and alkalis; the modified nanoparticles are used as a main material, such that the prepared membrane has the advantages of antibacterial and hydrophilic properties; a hydrophilic substance amino acid solution is grafted on the surfaces of the nanoparticles, such that on the one hand, the agglomeration phenomenon of the nanoparticles can be reduced, on the other hand, the hydrophilicity of the membrane can be further improved and the water output flux of the membrane can be further increased; the interaction of hydrophilicity is formed between the inside and the surface of the membrane, such that the anti-pollution capability of the membrane is more excellent. The present invention is simple and feasible in process operation, and has stable process parameters, low requirements on a process environment, and low costs.

Description

A kind of MBR flat filter membrane for domestic sewage treatment and preparation method thereof

technical field

The invention relates to the technical field of membranes, in particular to an MBR flat filter membrane for domestic sewage treatment and a preparation method thereof.

Background technique

MBR is the abbreviation of membrane bioreactor. It is a new wastewater treatment process produced by the organic combination of membrane technology and sewage biological treatment technology. MBR can be used to treat industrial wastewater and domestic sewage. It has a small footprint and stable effluent quality. , the remaining sludge output is small and so on. However, the problem of membrane fouling limits the application and promotion of membrane bioreactors to a certain extent. On the one hand, the appearance of membrane fouling will lead to a decrease in flux, which reduces the efficiency of sewage treatment. On the other hand, in order to reduce the impact of membrane fouling on sewage The impact of the treatment requires frequent cleaning of the MBR membrane, causing damage to the membrane surface and reducing the service life of the membrane. The use of cleaning agents will also increase the operating cost.

Membrane module is the core component of MBR technology. At present, MBR membrane modules are mainly made of hollow fiber and flat plate type. Among them, flat membrane module has the advantages of simple manufacturing and assembly, convenient operation, easy cleaning and replacement, etc. The material for making flat membrane module There are polysulfone, polyvinylidene fluoride, polyethylene, etc. Among them, polyethylene has the advantages of odorless and non-toxic, high air permeability, high crystallinity, good chemical stability, and resistance to most acid and alkali erosion. The vinyl membrane is hydrophobic, the effluent flux of the hydrophobic membrane is small, and the membrane surface is prone to membrane fouling.

SUMMARY OF THE INVENTION

In view of this, the present invention expects to provide an MBR modified membrane for domestic sewage treatment with good hydrophilicity, high flux, antibacterial and pollution resistance, and a preparation method thereof.

In order to achieve the above object, the technical scheme of the present invention is achieved in this way:

An object of the present invention is to provide a kind of preparation method of the MBR flat filter membrane used for domestic sewage treatment, and this method comprises the steps:

(1) Modification of nanoparticles

First add the nanoparticles into the dispersant solution for ultrasonic or stirring mixing, then add the silane coupling agent, heat and stir, with cooling water reflux during the heating process, filter the reacted solution and wash it with a cleaning agent, put it in a vacuum drying oven The modified nanoparticle powder is obtained by drying in the middle;

(2) Preparation of polyethylene casting solution

The polyethylene is added to the diluent for ultrasonication or stirring and mixing, then the modified nanoparticle powder and pore-forming agent prepared in step (1) are added, and ultrasonication or stirring is continued under heating conditions to obtain a polyethylene film casting liquid;

(3) Preparation of polyethylene flat film

The film-casting liquid prepared in step (2) is placed at room temperature for static defoaming, and then the film-casting liquid is extended to a clean glass plate. Scraping the film, after scraping the film, immersing it in the extractant, washing it with a cleaning agent, and drying it in a vacuum drying box to obtain a polyethylene flat film;

(4) Amino acid modification

The polyethylene flat film prepared in step (3) is first wetted in a wetting agent, then cleaned with a cleaning agent, and then immersed in an amino acid solution for reaction, and finally placed in an oven for heat treatment to obtain amino acid modified micropores membrane;

(5) Preparation of MBR flat filter element

The amino acid-modified microporous membrane obtained in step (4) is cleaned with a cleaning agent, dried at room temperature and then adhered to the ABS support plate with AB glue to obtain an MBR flat filter membrane element.

Further, in the step (1), the mass percentage of nanoparticles is 0.1% to 2%, the mass percentage of silane coupling agent is 1% to 5%, and the rest are dispersants.

Further, in the step (2), the mass percentage of polyethylene is 15% to 35%, the mass percentage of the modified nanoparticle powder is 3% to 8%, the pore former is 0.5% to 2%, and the rest are diluents .

Further, the dispersant in the step (1) is one of N-methylpyrrolidone (NMP), N-N dimethylacetamide (DMAc) and dimethylformamide (DMF).

Further, the silane coupling agent in the step (1) is one of KH-540, KH550, KH560, KH570 and KH602.

Further, the diluent in described step (2) is a kind of in white oil, paraffin oil and dimethyl phthalate (DMP).

Further, the pore-forming agent in the step (2) is one of polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), lithium chloride and calcium chloride.

Further, the molecular weight of polyethylene in the step (2) is between 1 million and 5 million.

Further, the amino acid in the step (4) is one of glycine, serine, lysine and aspartic acid.

Further, the nanoparticles in the step (1) are manganese dioxide nanoparticles, and the cleaning agent is one of ethanol, dichloromethane and acetone solution.

Further, in the steps (4) and (5), the wetting agent and the cleaning agent are one of ethanol, N-N dimethylacetamide and ethylene glycol solution.

Further, in the step (1), the heating temperature during the reaction is 60-150°C, the stirring time is 3-12h, and the set temperature of the vacuum drying box is 40-60°C.

Further, the heating condition in the step (2) is 180-230° C., the stirring speed is 200-300 r/min, and the stirring time is 2-5 h.

Further, in the step (3), the time for standing and defoaming is 6-8 hours, the time for soaking the extractant is 2-6 hours, and the thickness of the polyethylene flat film is 20-100 μm.

Further, the soaking time in the wetting agent in the step (4) is 2-4 h, the soaking time in the amino acid solution is 6-12 h, and the concentration of the amino acid solution is 0.02-0.2 mol/L, The temperature of the oven is set at 50-70° C., and the heat treatment time is 2-4 h.

Further, the cleaning agent in the steps (3), (4) and (5) is deionized water.

Further, the extractant in the step (3) is one of dichloromethane, cyclohexane, n-hexane and absolute ethanol.

Another object of the present invention is to provide an MBR flat filter membrane for domestic sewage treatment, including amino acid modified microporous membrane, AB glue, ABS support plate; the amino acid modified microporous membrane is pasted on the AB glue through AB glue the ABS support plate; the ABS support plate is fixedly provided with a diversion groove.

Further, the MBR flat filter membrane exhibits a three-dimensional interpenetrating network structure.

Further, the amino acid-modified microporous membrane is made by grafting modified nanoparticles and amino acids.

Furthermore, the component casting solution of the amino acid modified microporous membrane is made of polyethylene, diluent, modified nanoparticles and pore-forming agent.

The beneficial effects of the present invention are as follows:

1) The present invention provides a method for preparing an MBR flat filter membrane for domestic sewage treatment. Polyethylene is used as the main material, and the polyethylene itself has high air permeability, high crystallinity, good chemical stability and high resistance. The advantages of corrosion of most acids and bases improve the chemical stability of the membrane;

2) The present invention adopts the modified nanoparticles as the main material, which will make the prepared film have the advantages of antibacterial and hydrophilic properties;

3) The present invention grafts the hydrophilic substance amino acid solution on the surface of the nano-particles, on the one hand, the phenomenon of nano-particle agglomeration can be reduced, and on the other hand, the hydrophilicity of the membrane can be further improved, and the effluent flux of the membrane can be increased;

4) The flat membrane prepared by the present invention has the combined effect of forming hydrophilicity inside the membrane and making the membrane more excellent in anti-fouling ability;

5) The process of the present invention is simple and easy to operate, the equipment used are all conventional instruments in the field, the process parameters are stable, the requirements for the process environment are low, and the cost is low.

Description of drawings

1 is a schematic diagram of a nanoparticle modification reaction process according to an embodiment of the present invention;

2 is a schematic diagram of an amino acid modification reaction process according to an embodiment of the present invention;

3 is a scanning electron microscope image of an MBR flat filter membrane for domestic sewage treatment prepared by an embodiment of the present invention, showing a three-dimensional interpenetrating network structure;

4 is a schematic diagram of an MBR flat membrane element prepared by an embodiment of the present invention;

Component label description

1 ABS support plate

2 diversion grooves

3 Amino acid modified microporous membrane

detailed description

The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, but not to limit the present invention.

As shown in Figures 1 and 2, a specific embodiment of the present invention provides a method for preparing an MBR flat filter membrane for domestic sewage treatment, the method comprising the following steps:

(1) Modification of nanoparticles

(2) Preparation of polyethylene casting solution

(3) Preparation of polyethylene flat film

(4) Amino acid modification

The polyethylene flat film prepared in step (3) is first wetted in a wetting agent, then cleaned with a cleaning agent, and then immersed in an amino acid solution for reaction, and finally placed in an oven for heat treatment to obtain amino acid modified micropores membrane 3;

(5) Preparation of MBR flat filter element

The amino acid modified microporous membrane 3 prepared in step (4) is cleaned with a cleaning agent, dried at room temperature and then adhered to the ABS support plate 1 with AB glue to obtain an MBR flat filter membrane element.

Preferably, in the step (1), the mass percentage of nanoparticles is 0.1% to 2%, the mass percentage of silane coupling agent is 1% to 5%, and the rest are dispersants.

Preferably, in the step (2), the mass percentage of polyethylene is 15%-35%, the mass percentage of the modified nanoparticle powder is 3%-8%, the pore-forming agent is 0.5%-2%, and the rest are diluents .

Preferably, the dispersant in the step (1) is one of N-methylpyrrolidone, N-N dimethylacetamide and dimethylformamide.

Preferably, the silane coupling agent in the step (1) is one of KH-540, KH550, KH560, KH570 and KH602.

Preferably, the diluent in the step (2) is one of white oil, paraffin oil and dimethyl phthalate.

Preferably, the pore-forming agent in the step (2) is one of polyethylene glycol, polyvinylpyrrolidone, lithium chloride and calcium chloride.

Preferably, the molecular weight of polyethylene in the step (2) is between 1 million and 5 million.

Preferably, the amino acid in the step (4) is one of glycine, serine, lysine and aspartic acid.

Preferably, the nanoparticles in the step (1) are manganese dioxide nanoparticles, and the cleaning agent is one of ethanol, dichloromethane and acetone solution.

Preferably, the wetting agent in the steps (4) and (5) is one of ethanol, N-N dimethylacetamide and ethylene glycol solution.

Preferably, in the step (1), the heating temperature during the reaction is 60-150°C, the stirring time is 3-12h, and the set temperature of the vacuum drying box is 40-60°C.

Preferably, the heating condition in the step (2) is 180-230° C., the stirring speed is 200-300 r/min, and the stirring time is 2-5 h.

Preferably, in the step (3), the time of standing for defoaming is 6-8 hours, the time of soaking the extractant is 2-6 hours, and the thickness of the polyethylene flat film is 20-100 μm.

Preferably, the soaking time in the wetting agent in the step (4) is 2-4 h, the soaking time in the amino acid solution is 6-12 h, and the concentration of the amino acid solution is 0.02-0.2 mol/L, The temperature of the oven is set at 50-70° C., and the heat treatment time is 2-4 h.

Preferably, the cleaning agent in the steps (3), (4) and (5) is deionized water.

Preferably, the extractant in the step (3) is one of dichloromethane, cyclohexane, n-hexane and absolute ethanol.

As shown in Figure 4, the specific embodiment of the present invention also provides an MBR flat filter membrane for domestic sewage treatment, including amino acid modified microporous membrane 3, AB glue (not shown in the figure), and ABS support plate 1; The amino acid modified microporous membrane 3 is pasted on the ABS support plate 1 by AB glue; the ABS support plate 1 is fixedly provided with a diversion groove 2 .

Preferably, the MBR flat filter membrane exhibits a three-dimensional interpenetrating network structure (as shown in FIG. 3 ).

Preferably, the amino acid-modified microporous membrane 3 is made by grafting modified nanoparticles and amino acids.

Specifically, the component casting solution of the amino acid-modified microporous membrane 3 is made of polyethylene, a diluent, modified nanoparticles and a pore-forming agent.

The present invention will be described in detail below by means of examples.

In the following examples and comparative examples, performance parameters were determined as follows:

Membrane performance tests were performed in accordance with GB/T32360-2015, GB/T30693-2014 and QB/T2591-2003. The thickness is measured by German Marr Film Thickness Gauge C1216 according to GB/T6672-2001 Determination Method for Thickness of Plastic Films and Sheets. The same sample is tested 5 times, and the average value is taken as the average thickness.

Example 1:

First, 0.1% manganese dioxide nanoparticles were added to the NMP solution for ultrasonic mixing, then 1% KH-540 was added, and heated and stirred at 60 °C for 3 hours. During the heating process, cooling water was refluxed. The reacted solution was filtered and used The modified nanoparticle powder was obtained by washing with ethanol solution and drying in a vacuum drying oven at 40°C.

15% PE (Mn=1 million) was added to white oil (81.5%) and ultrasonically mixed, then 3% modified manganese dioxide powder and 0.5% PEG were added at 180°C and stirred for 2h at 200r/min. The PE casting liquid was obtained.

The obtained casting solution was placed at 25°C for 6 hours to defoaming, and then the casting solution was spread on a clean glass plate. During the casting process, a film scraper was used to scrape the casting solution on the glass plate. , to obtain a polyethylene flat film with a thickness of 100 μm, which was immersed in dichloromethane solution for 2 h, and the extracted base film was washed with deionized water and dried in a vacuum drying oven at 30 °C.

The polyethylene flat film was first soaked in ethanol solution for 2h to wet, then washed with detergent, then soaked in 0.02mol/L glycine solution, reacted for 6h, and then placed in a 50°C oven for 2h heat treatment to obtain amino acids Modified microporous membrane. The obtained modified membrane was washed with deionized water, and then air-dried at 25°C. The performance test is shown in Table 1.

Example 2:

First, 0.5% manganese dioxide nanoparticles were added to the DMAc solution for ultrasonic mixing, then 2% KH550 was added, and heated and stirred at 80 °C for 5 h. During the heating process, cooling water was refluxed. The reacted solution was filtered with dichloromethane. The solution was cleaned and dried in a vacuum drying oven at 40°C to obtain the modified nanoparticle powder.

20% PE (Mn=1.5 million) was added to paraffin oil (75%) and ultrasonically mixed, then 4% modified manganese dioxide powder and 1% PVP were added at 180°C and stirred at 220r/min for 3h. The PE casting liquid was obtained.

The casting solution was placed at room temperature for 6 hours to deaerate, and then the casting solution was spread on a clean glass plate. During the casting process, a film scraper was used to scrape the casting solution on the glass plate to obtain A polyethylene flat film with a thickness of 50 μm was soaked in a cyclohexane solution for 3 hours. The extracted film was washed with deionized water and then dried in a vacuum drying oven at 40°C.

The polyethylene flat film was first soaked in DMAc solution for 2h to wet, then washed with detergent, then soaked in 0.05mol/L serine solution, reacted for 7h, and then placed in a 50°C oven for 2h heat treatment to obtain amino acids Modified microporous membrane. The obtained modified membrane was washed with deionized water, and then air-dried at 25°C. The performance test is shown in Table 1.

Example 3:

First, ultrasonically mix 1% manganese dioxide nanoparticles in DMF solution, then add 4% KH570, heat and stir at 120°C for 10h, with cooling water reflux during the heating process, filter the reacted solution and wash it with ethanol solution , and dried in a vacuum drying oven at 60°C to obtain the modified nanoparticle powder.

Add 30% PE (Mn = 2 million) to DMP solution (63.5%) for ultrasonic mixing, then add 5% modified manganese dioxide powder and 1.5% lithium chloride at 210°C and stir at 240r/min 4h, the PE casting liquid was obtained.

Put the casting solution at 25°C for 6 hours for defoaming, and then spread the casting solution onto a clean glass plate. During the casting process, use a scraper to scrape the casting solution on the glass plate. A polyethylene flat film with a thickness of 20 μm was obtained, which was immersed in n-hexane solution for 4 h. The extracted base film was washed with deionized water and then dried in a vacuum drying oven at 60°C.

The polyethylene flat film was first soaked in DMAc solution for 3h to wet, then washed with detergent, then soaked in 0.1mol/L lysine solution, reacted for 8h, and then placed in an oven at 60 °C for heat treatment for 3h. Amino acid-modified microporous membranes were obtained. The obtained modified membrane was washed with deionized water, and then air-dried at 25°C. The performance test is shown in Table 1.

Example 4:

The 1.5% manganese dioxide nanoparticles were added to the DMF solution for ultrasonic mixing, then 3% KH570 was added, and heated and stirred at 100 °C for 8 h. During the heating process, cooling water was refluxed. The reacted solution was filtered and washed with acetone solution. The modified nanoparticle powder was obtained by drying in a vacuum drying oven at 50°C.

Add 25% PE (Mn = 4 million) to the white oil solution (67%) and ultrasonically mix, then add 6% modified manganese dioxide powder and 2% calcium chloride at 220 ° C, under the speed of 260 r/min Stir for 5h to obtain PE casting liquid.

Put the casting solution at 25°C for 8 hours to defoaming, and then spread the casting solution onto a clean glass plate. During the casting process, use a scraper to scrape the casting solution on the glass plate. A polyethylene flat film with a thickness of 30 μm was obtained, which was immersed in anhydrous ethanol solution for 4 h. The extracted base film was washed with deionized water and then dried in a vacuum drying oven at 60°C.

The polyethylene flat film was first soaked in ethylene glycol solution for 4 hours to wet, then washed with cleaning agent, then soaked in 0.15mol/L aspartic acid solution, reacted for 10 hours, and then placed in an oven at 70 °C The amino acid-modified microporous membrane was prepared by heat treatment for 4h. The obtained modified membrane was washed with deionized water, and then air-dried at 25°C. The performance test is shown in Table 1.

Example 5:

The NMP solution added with 2% manganese dioxide nanoparticles was ultrasonically mixed, then 5% KH602 was added, heated and stirred at 150 °C for 12 hours, and the heating process was accompanied by cooling water reflux. The reacted solution was filtered and washed with ethanol solution. The modified nanoparticle powder was obtained by drying in a vacuum drying oven at 60°C.

Add 35% PE (Mn=5 million) to the white oil solution (55%) and mix with ultrasonic, then add 8% modified manganese dioxide powder and 2% PEG at 230°C and stir at 300r/min for 5h , to obtain PE casting liquid.

Put the casting solution at 25°C for 8 hours to defoaming, and then spread the casting solution onto a clean glass plate. During the casting process, use a scraper to scrape the casting solution on the glass plate. A polyethylene flat film with a thickness of 55 μm was obtained, which was immersed in anhydrous ethanol solution for 6 h. The extracted base film was washed with deionized water and then dried in a vacuum drying oven at 60°C.

The polyethylene flat film was first soaked in ethanol solution for 4h to wet, then washed with detergent, then soaked in 0.2mol/L lysine solution, reacted for 12h, and then placed in an oven at 70°C for heat treatment for 4h. Amino acid-modified microporous membranes were obtained. The obtained modified membrane was washed with deionized water, and then air-dried at 25°C. The performance test is shown in Table 1.

Comparative Example 1

The DMF solution added with 1% manganese dioxide nanoparticles was ultrasonically mixed, then 4% KH570 was added, heated and stirred at 120 °C for 10 h, and the heating process was accompanied by cooling water reflux. The reacted solution was filtered and washed with ethanol solution. The modified nanoparticle powder was obtained by drying in a vacuum drying oven at 60°C.

Add 30% PE (Mn=2 million) to DMP solution (68.5%) and mix with ultrasonic, then add 5% modified manganese dioxide powder and 1.5% lithium chloride at 210°C and stir at 240r/min 4h, the PE casting liquid was obtained.

Put the casting solution at 25°C for 6 hours for defoaming, and then spread the casting solution onto a clean glass plate. During the casting process, use a scraper to scrape the casting solution on the glass plate. A polyethylene flat film with a thickness of 20 μm was obtained, which was soaked in n-hexane solution for 4 h. The extracted film was washed with deionized water and then dried in a vacuum drying oven at 60 °C. The performance test is shown in Table 1.

Comparative Example 2

30% PE (Mn=2 million) was added to the DMP solution (68.5%) for ultrasonic mixing, then 1.5% lithium chloride was added and stirred for 4 hours at 210°C and 240r/min to obtain a PE casting solution.

The polyethylene flat film was first soaked in DMAc solution for 3h to wet, then washed with cleaning agent, then soaked in 0.1mol/L lysine solution, reacted for 8h, and then placed in an oven at 60 °C for heat treatment for 3h. Amino acid-modified microporous membranes were obtained. The obtained modified membrane was washed with deionized water, and then air-dried at 25°C. The performance test is shown in Table 1.

Table 1. Flux, Contact Angle, Fouling Resistance and Antibacterial Rate of Ultrafiltration Membranes of Example and Comparative Examples

Note: The pollution resistance in the table is calculated by the number of operating days when the transmembrane pressure difference reaches 32Kpa.

It can be seen from Table 1 that the flux, pollution resistance and antibacterial properties of the membrane can be significantly improved under the combined action of the addition of modified manganese dioxide nanoparticles and the infiltration of amino acid solution.

Table 2 Test results of MBR flat membrane elements for sewage treatment

膜元件外框尺寸(mm)Membrane element frame size (mm)	140×180140×180
有效膜面积(m2)Effective membrane area (m2)	0.3840.384
曝气(气水比)Aeration (air to water ratio)	30:130:1
出水浊度(NTU)Outlet Turbidity (NTU)	<1<1
出水COD(mg/L)Effluent COD(mg/L)	18.218.2
出水BOD(mg/L)Effluent BOD(mg/L)	3.53.5
出水氨氮(mg/L)Ammonia nitrogen in effluent (mg/L)	2.32.3
出水悬浮物(mg/L)Effluent suspended solids (mg/L)	1.61.6

Table 2 shows the test results of the membrane element produced in Example 3 in Table 1 for sewage treatment. The test results show that the effluent indicators all meet the Class A Class A discharge standard of the urban sewage treatment plant pollutant discharge standard.

The above content related to common knowledge will not be described in detail, which can be understood by those skilled in the art.

The above are only some specific embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the present invention. within the scope of protection. The technical scope of the present invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

A method for preparing an MBR flat filter membrane for domestic sewage treatment, characterized in that the method comprises the following steps:

(1) Modification of nanoparticles

First, the nanoparticles are added to the dispersant for mixing, then the silane coupling agent is added, heated and stirred, and the reacted solution is suction filtered, washed, and dried to obtain modified nanoparticle powder;

(2) Preparation of polyethylene casting solution

Adding the modified nanoparticle powder and pore-forming agent prepared in step (1) to the polyethylene mixed solution to obtain a polyethylene casting solution;

(3) Preparation of polyethylene flat film

The film casting liquid prepared in step (2) is spread on a glass plate to obtain a polyethylene flat film;

(4) Amino acid modification

The polyethylene flat membrane prepared in step (3) is soaked in the amino acid solution for reaction, and the amino acid modified microporous membrane is obtained by post-heat treatment;

(5) Preparation of MBR flat filter element

The amino acid-modified microporous membrane prepared in step (4) is adhered to a support plate to obtain an MBR flat filter element.
The preparation method according to claim 1, characterized in that: in the step (1), the mass percentage of the nanoparticles is 0.1%-2%, the mass percentage of the silane coupling agent is 1%-5%, and the rest is dispersed agent.
The preparation method according to claim 1, characterized in that: in the step (2), the mass percentage of polyethylene solute is 15% to 35%, and the mass percentage of the modified nanoparticle powder is 3% to 8%. The pore agent is 0.5% to 2%, and the rest is mixed diluent.
The preparation method according to claim 1, wherein the dispersant in the step (1) is one of N-methylpyrrolidone, N-N-dimethylacetamide and dimethylformamide.
The preparation method according to claim 1, wherein the silane coupling agent in the step (1) is one of KH-540, KH550, KH560, KH570 and KH602.
The preparation method according to claim 3, wherein the mixed diluent is one of white oil, paraffin oil and dimethyl phthalate.
The preparation method according to claim 1, wherein the pore-forming agent in the step (2) is one of polyethylene glycol, polyvinylpyrrolidone, lithium chloride and calcium chloride.
The preparation method according to claim 1, wherein the molecular weight of the polyethylene in the step (2) is between 1 million and 5 million.
The preparation method according to claim 1, wherein the amino acid in the step (4) is one of glycine, serine, lysine and aspartic acid.
The preparation method according to claim 1, characterized in that: the nanoparticles in the step (1) are manganese dioxide nanoparticles, and the cleaning agent during the cleaning is one of ethanol, dichloromethane and acetone solution. kind.
The preparation method according to claim 1, characterized in that: in the step (1), the heating temperature during the reaction is 60-150°C, the stirring time is 3-12h, and the drying temperature is 40-60°C.
The preparation method according to claim 1, wherein the thickness of the polyethylene flat film is 20-100 μm.
The preparation method according to claim 1, wherein the time of soaking in the amino acid solution is 6-12 h, the concentration of the amino acid solution is 0.02-0.2 mol/L, and the heat treatment temperature is set to 50-70 ℃, the time is 2 ~ 4h.
An MBR flat filter membrane for domestic sewage treatment, characterized in that: it comprises an amino acid modified microporous membrane, AB glue, and an ABS support plate; the amino acid modified microporous membrane is pasted on the ABS support through AB glue The ABS support plate is fixedly provided with a diversion groove.
The MBR flat filter membrane for domestic sewage treatment according to claim 14, wherein the MBR flat filter membrane exhibits a three-dimensional interpenetrating network structure.
The MBR flat filter membrane for domestic sewage treatment according to claim 14, wherein the amino acid modified microporous membrane is made by grafting modified nanoparticles and amino acids.
The MBR flat filter membrane for domestic sewage treatment according to claim 16, wherein the component casting liquid of the amino acid modified microporous membrane is composed of polyethylene, diluent, modified nanoparticles and pore-forming agent production.