Chitosan-modified acrylic nanofiltration membrane for efficient removal of pharmaceutical compounds

Abstract

Recently, significant number of research efforts have been directed toward the assessment and removal of pharmaceuticals in the aquatic environment. Among all processes, membrane technologies have taken little notice of their performances in this field because of membrane fouling. In this research, we attempted to take advantage of chitosan as an excellent antifouling agent for thin-film composite nanofiltration membranes. Polyamide skin layer was synthesized by reacting 0.2% wt. of ethylene diamine and 0.1% w/v of trimesoyl chloride on acrylic membrane support via interfacial polymerization technique. Afterwards, amine groups in chitosan chains (0.1% wt.) reacted with un-reacted acyl chloride to modify membrane surface. By this chance, surface roughness and contact angle decreased significantly. This membrane had the best performance for diphenhydramine (97%) and mebeverine (∼98%) at pH=3 with the least fouling (22.6 L/m2h, FRR=94.21%).