Preparation and performance research of anti-fouling composite polyamide nanofiltration membrane

A composite polypiperazine-amide nanofiltration membrane,supported by polysulfone(PSF)ultrafiltration membrane,was prepared via interfacial polymerization of piperazine(PIP)and trimesoyl chloride(TMC)in the present of polyvinyl alcohol(PVA).The effects of PVA,PIP and TMC concentration,temperature and time of heat treatment on the composite membrane were studied,and the surface structure and morphology were analyzed by scanning electron microscope(SEM)and atomic force microscopy(AFM).The experiment results showed that increasing PVA content would lead to the increase in the flux of the nanofiltration membrane,make the nanofiltration membrane more hydrophilic,and cause the surface of the nanofiltration membrane smoother.The optimal preparing condition of the composite membrane was 3.0 g/L TMC,1.0 g/L PIP,0.54 g/L PVA,1 min reaction time,and 10 min heat treatment at 50 ℃.The separation performance of self-made nanofiltration membrane,treating the solutions of Na2SO4,MgSO4,NaCl or MgCl2,was similar to that of the commercial nanofiltration membranes,such as Dow NF-270 and Synder.Furthermore,the nanofiltration membrane also showed very good separation and anti-fouling performance in the advanced treatment of deinking wastewater.