Modified graphene oxide (GO) embedded in nanofiltration membranes with high flux and anti-fouling for enhanced surface water purification

Nanofiltration membranes effectively remove natural organic matter (NOM) while retaining trace minerals needed by the human body, which is important for achieving high-quality drinking water treatment. In this study, the high-flux and fouling-resistant nanofiltration membranes were prepared through a simple process with piperazine (PIP) and tricarbonyl chloride (TMC) were used as the aqueous and organic phase monomers, respectively, as well as graphene oxide (GO) was embedded in the polyamide active layer via interfacial polymerization. In addition to providing an abundance of negative charges on the membrane surface, the typical quasi-two-dimensional spatial structure of GO and numerous carboxyl and hydroxyl reactive groups on its lamellae effectively reduce the rate at which the aqueous monomers react with TMC, resulting in improve the membrane surface's folding, and increase its roughness. The GO-TFC membrane showed the optimal separation performance with maximal flux recovery rates of bovine serum protein, humic acid and sodium alginate were 92.57 %, 97.39 % and 98.79 %, respectively. At 0.4 MPa, the membrane also exhibited superior anti-fouling property with a high level of Na2SO4 rejection (98.14 %) and a water flux of 50.47 L & sdot; m- 2 & sdot; h- 1 under ideal circumstances. The purification efficacy and anti-fouling mechanism of NF membranes efficiently purifying contaminated surface water were further investigated.