Super-antifouling PES nanocomposite membrane encapsulated silica nanoparticles and coated nano-Ag/polyvinyl alcohol layer

Abstract

Antifouling membranes were developed by encapsulating amino-functionalized nano-silica in polymeric mixes of polyethersulfone (PES) and polyvinyl pyrrolidone (PVP). Subsequently, the membranes were modified with a nano-Ag/PVP coating layer. The membranes’ performance was assessed against synthetic whey solutions model to mimic dairy wastewater. Various techniques were harnessed to evaluate the membranes' composition, structure and morphology, including SEM, XPS, XRD, AFM, mechanical characteristics, porosities and contact angles. Findings indicated that nanocomposite made with 1.5 % amino-functionalized nano-silica (M3) revealed optimum performance and was capable to separate 90 % of the whey in the feed along with a permeate flux of 238 L/m2.h, when the feed whey concentration was 0.4°Brix. the equivalent membrane but coated with a nano-Ag /PVP layer (M3S) displayed a trivial drop in permeate flux (229.3 L/m2.h) comparing to uncoated one. Nonetheless, the addition of the coating boosted the separation efficiency up to 99.7 % of the whey in the feed. The fouling test indicated that the coated membrane (M3S) had superior antifouling property, where flux recovery ratio (FRR) hit 99.5 % with a diminution in the backwash rate.

Keywords

• Fouling
• Silica
• Nanosilver
• Polyvinylalcohol
• Whey
• Nanocomposite membrane