Preparation of CMC/PPy/PVDF composite membrane and its dye/salt separation performance
In dyeing and printing wastewater treatment,how to efficiently separate dye/salt wastewater is an urgent problem.This project is to achieve efficient dye/salt selective separation and improve the membrane flux.Using polyvinylidene fluoride(PVDF)as the base membrane,carboxymethylcellulose(CMC)gel assisted by tannic acid was used to construct a stable gel layer through layer-by-layer cross-linking in order to reduce membrane contamination and improve the membrane flux,and then polymerised with polypyrrole on the surface of it in order to prepare a composite membrane to further improve the rejection rate.The microstructure,hydrophilicity,electrophilicity,dye/salt separation and operational stability of the membrane were investigated.The results showed that the membrane has high rejection of five typical dyes(>99%)and high flux to pure water[91.7 L/(m2·h)],and also has good dye/salt separation performance(dye rejection>99%,salt rejection<6%).