Incorporation of silica grafted silver nanoparticles into polyvinyl chloride/polycarbonate hollow fiber membranes for pharmaceutical wastewater treatment

Polyvinyl chloride/polycarbonate hollow fiber membranes incorporated with modified silver nanoparticles were prepared by wet spinning method. Fabricated membranes were then characterized by FESEM, EDX, TGA, contact angle, pure water flux and mechanical tests. It was found that the addition of modified silver nanoparticles changed the structure of hollow fiber membranes and the size of macrovoids in the middle layer decreased whereas the thickness of sponge-like outer layer increased. The results of EDX analysis showed that the modified silver nanoparticles were dispersed uniformly throughout the membranes. In addition, degradation temperature of the membranes increased as the content of nanoparticles increased which shows that thermal resistance of membranes was improved. The number of pores on the membrane surface increased due to the presence of nanoparticles but mean pore radius decreased. Addition of modified nanoparticles also improved hydrophilicity, tensile strength and elongation of hollow fiber membranes. The membranes were finally used in a membrane bioreactor system with pharmaceutical wastewater feed during 28 days and the results revealed that incorporation of modified silver nanoparticles enhanced antifouling properties of hollow fiber membranes. Moreover, pure water flux and COD removal as the criteria of membrane performance increased simultaneously. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.