High performance chromium (VI) removal from water by polyacrylonitrile-co-poly (2-ethyl hexylacrylate) and polyaniline nanoporous membranes

This article reports the chromium (VI) removal from water by preparing polyacrylonitrile-co-poly (2-ethyl hexylacrylate) (PAN(92)-co-P2EHA(8)) and polyaniline (PANI) nanoporous membranes at various PANI loadings. It was observed that chromium (VI) rejections of nanoporous membranes are highly concentration and pH dependent. Almost complete chromium removal (99.9%) with higher flux values (120-177 L m-2 h-1) was observed for nanoporous membranes. Moreover, nanoporous membranes were also demonstrated as fouling resistant. Total flux loss was low and a part was attributed to reversible flux loss, which cannot cause any permanent hysteresis and easily overcome with simple washing. Scanning electron microscopy (SEM) studies were performed for identifying cross sectional morphology. It was pointed out that pore size should be small enough for filtration and optimized for higher flux but pores should be functionalized for rejection. Chemical structure, swelling ratios, sheet resistivity, and fracture morphologies of nanoporous membranes were reported. POLYM. ENG. SCI., 2012. (C) 2012 Society of Plastics Engineers