▎ 摘　　要

NOVELTY - Producing anti-contaminated flat film membrane involves preparing graphene oxide by adding 200-250mL of concentrated sulfuric acid to 1L three-necked flask in an ice water bath, slowly, adding 10-15g graphite and 3-5g sodium nitrate in flask, carrying out grinding and stirring for 1-1.5 hours, adding 25-35g potassium permanganate in bath, carrying out mechanical stirring of mixture in an ice water bath for 1.5-2 hours, heating to 30-40 degrees C for 2-2.5 hours, adding 200-250mL deionized water at 30-40 degrees C, heating reaction system to 80-90 degrees C, and stirring for 10-20 minutes. USE - Method for producing anti-contaminated flat film membrane for removing heavy metal ion and organic dye. ADVANTAGE - The method enables to produce anti-contaminated flat film membrane, which reaches chromium ions adsorption removal rate to more than 90%, shows static protein adsorption test, reduces protein adsorption rate by 80%, does not need special equipment, and has easy industrialization implement and reduced cost. DETAILED DESCRIPTION - Producing anti-contaminated flat film membrane involves preparing graphene oxide by adding 200-250mL of concentrated sulfuric acid to 1L three-necked flask in an ice water bath, slowly, adding 10-15g graphite and 3-5g sodium nitrate in flask, carrying out grinding and stirring for 1-1.5 hours, adding 25-35g potassium permanganate in bath, carrying out mechanical stirring of mixture in an ice water bath for 1.5-2 hours, heating to 30-40 degrees C for 2-2.5 hours, adding 200-250mL deionized water at 30-40 degrees C, heating reaction system to 80-90 degrees C, stirring for 10-20 minutes, adding 400-500mL deionized water to system, stirring for 2 minutes, and adding 20-25mL hydrogen peroxide to terminate reaction. The obtained reaction mixture is continuously stirred for 10-20 minutes, mixture is centrifuged and repeatedly washed with dilute hydrochloric acid and deionized water until pH of the product reaches to 7. The attapulgite is pre-treated by weighing 10-20g of attapulgite with a particle size of 300-1000 mesh, washing with 1L distilled water, and supernatant is taken after precipitation. The supernatant is centrifuged at 500 revolutions per minute for 1 minute. Small amount of distilled water is added to supernatant and mixed uniformly, and centrifuged at 500 revolutions per minute for 1 minute to obtain supernatant, which is washed for 3-5 times, centrifuged at 4000 revolutions per minute to obtain precipitate. The precipitate is vacuum dried at 90 degrees C for 24 hours, grounded, sieved with corresponding mesh size according to particle size to obtain the purified attapulgite. The hydrochloric acid solution having concentration of 0.5-3mol/L is configured, and 10-20g purified attapulgite clay and 150-200mL of hydrochloric acid solution is added to a small beaker, stirred and mixed for 5 minutes to obtain mixture. The mixture is heated to 70-80 degrees C for 1-2 hours, subjected to ultrasonic vibration for 30-40 minutes, subjected to suction filtration, and washing with distilled water to pH 6, and then subjected to vacuum drying at 90 degrees C for 24 hours, grounded according to particle size of corresponding screen to sieve to obtain acid-modified attapulgite. The method involves taking 1-3g acid-modified attapulgite, adding 200-250mL of 2000mg/L tannic acid solution, stirring at room temperature for 2-3 hours, washing with ethanol to obtain supernatant, which is subjected to centrifugal separation with ferric chloride solution without color reaction, grounded according to particle size and sieved with corresponding mesh number to obtain tannic acid modified attapulgite. The casting solution is prepared by mixing polyvinylidene difluoride (PVDF) and tannic acid modified attapulgite clay according to mass ratio of 1:0.1 to 1:0.5, and weighing certain amount of PVDF and tannic acid modified attapulgite clay and adding N,N-dimethylformamide and polyethylene glycol in a container. The container is placed in a water bath at 50-70 degrees C, and attapulgite is uniformly dispersed by stirring and ultrasonic vibration. The method involves mixing 1-2 wt.% PVDF mass, 20-300nm nano-ZnO, 20-50 wt.% ZnO and graphene oxide, grounding, and dispersing in casting solution, and subjected to ultrasonic reaction for 2 hours, and vacuum defoaming. The basement film is prepared by pouring casting solution on a glass plate, scrapping into a film with a glass rod, and immersing in a constant temperature coagulation bath at 20-30 degrees C, and detaching film from glass plate, and washing film with distilled water for 24-36 hours to obtain a base film. The flat membrane is prepared by treating 1.0894g base membrane with 2.5mol/L potassium hydroxide solution at 60 degrees C for 5-25 minutes, and washing membrane with distilled water for multiple times, drying, rinsing with ethanol to remove impurities from membrane surface. The method involves using 6.0-8.0g of poly((3-(methacryloylamino)propyl)-dimethyl(3-sulfopropyl)ammonium hydroxide) (MPDSAH) as a modifier, methanol as a solvent, 0.2-0.8 wt.% NN-methylenebisacrylamide as a cross-linking agent, and 0.5-2 wt.% 2-2,-azobisisobutyronitrile as initiator and is reacted under a nitrogen atmosphere at 50-60 degrees C for 24 hours, and surface of membrane is washed for multiple times with 0.1 mol/L sodium chloride solution and distilled water to remove it. The unreacted monomer is used to obtain final product.