(376bc) Metal Oxide Functionalized Graphene Oxide Membranes for Advanced Oxidation of Pollutants

Fast water transport, ease of membrane fabrication, separation on nanoscale, mechanical and thermal stability and stability in solvent media has made Graphene Oxide (GO)-based membranes a promising candidate for nanofiltration. Additionally, their ability to catalyze redox reactions have attracted much attention in environmental remediation of toxic organics. Aim of this study is to combine the ability of GO membranes for nanoscale separations with pursulfate mediated removal of smaller chlorinated organics from water. A novel membrane platform consisting of partially reduced GO and polyacrylic acid was fabricated using layer by layer assembly approach. Iron nanoparticles were embedded in the membrane domain by in-situ synthesis from ferrous ion precursors immobilized on the introduced carboxylic groups of polyacrylic acid. Extensive exclusion studies with various salts and dyes showed that the fabricated membranes retained separation abilities of the conventional GO membranes. Catalytic property of the GO membranes were investigated in a cross flow mode of operations. Extended study over 20 hours showed effective decomposition of persulfate on passing its aqueous solution (500 ppm) through the fabricated membranes for an operating flux of 2 LMH, pH 6.5 and 23^oC. Evaluation of effectiveness of the fabricated membranes for removal of trichloroethylene (TCE) under same operating conditions showed near 100% removal of TCE (from 30 ppm feed). The GO-based platform with its capabilities of separation on nanoscale and catalyzing oxidative removal of toxic organics can further help in achieving more efficient water purification. This research is supported by the NIEHS-SRP (Grant no: P42ES007380) and NSF KY EPSCoR (Grant no: 1355438).