Method for purifying dye-containing wastewater based on porous-polymer-modified metal carbon nanotube composite membrane

A method for purifying dye-containing wastewater based on a porous-polymer- modified metal carbon nanotube membrane, comprising:

• (1) preparing the porous-polymer-modified metal carbon nanotube membrane, which comprises:
• immersing a carbon nanotube membrane in aqua regia for acidification to obtain an acidified carbon nanotube membrane;
• preparing a modification solution that includes a zirconium salt, terephthalic acid, acetic acid, and a solvent;
• heating the acidified carbon nanotube membrane in the modification solution and reacting to obtain a metal carbon nanotube membrane;
• conducting a polymerization reaction of 2,3,5,6-tetrafluoroterephthalonitrile and 5,5′,6,6′-tetrahydroxy-3,3′,4,4′-tetramethyl-1,1′-spiralbisindan, under nitrogen atmosphere and in the presence of anhydrous potassium carbonate, to obtain a crude polymer product;
• precipitating the crude polymer product in methanol, dissolving the crude product in chloroform, precipitating the crude polymer product in methanol, and heating the crude polymer product in water to obtain a porous polymer;
• preparing a polyethylene glycol diglycidyl ether (PEGDEG) solution and coating the metal carbon nanotube membrane with the polyethylene glycol diglycidyl ether solution;
• preparing a porous polymer solution and coating the metal carbon nanotube membrane with the porous polymer solution;
• and
• heating the metal carbon nanotube membrane to obtain the porous-polymer- modified metal carbon nanotube membrane;
• and
• (2) passing the dye-containing wastewater through the porous-polymer-modified metal carbon nanotube membrane to remove dyes in the dye-containing wastewater.