A novel chlorine-resistant polyacrylate nanofiltration membrane constructed from oligomeric phenolic resin

Abstract

Conventional water treatment polyamide nanofiltration (NF) membranes often suffer from the degradation of sodium hypochlorite (NaOCl) in sewage or during the process of membrane cleaning and deteriorate the separation performance, which significantly increases the treatment cost. Herein, a novel polyacrylate composite NF membranes were prepared by interfacial polymerization using oligomeric phenolic resin (OPR) and trimesoyl chloride (TMC) as aqueous and organic phase monomer respectively on the polyethersulfone (PES) ultrafiltration supporting membranes. The fabrication parameters, including the pH of the aqueous solution, reaction time and the concentration of the monomer, on the performance of the composite NF membranes were optimized. A series of characterization indicated that the surface of the NF membranes was negatively charged, the molecular weight cut-off (MWCO) and the pore diameter of the polyacrylate membrane were 400 Da and 0.47 nm, respectively. At the optimized preparation conditions, the NF membrane exhibited high Na2SO4 rejection of 98.2% and water flux of 2.42L·m−2·h−1·bar−1, which was superior to most of the polyacrylate NF membranes reported in recent years. Compared with the polyamide membrane, the prepared polyacrylate membrane demonstrated better chlorine-resistant property and still maintained 92.0% Na2SO4 rejection after being treated with NaOCl solution. Moreover, the NF membrane preserved excellent long-term operation stability. The chlorine-resistant NF membrane constructed from OPR monomer has a broad application prospect in the field of high chlorine wastewater treatment.