Fast Reduced Graphene-Based Membranes with High Desalination Performance

Abstract

Graphene-oxide (GO) membrane with notable ions sieving properties has attracted significant attention for many applications. However, because of the water swelling of GO membrane, the rejection of monovalent metal cations is generally low. In this work, we developed a fast and facile method to fabricate a kind of reduced GO membranes using the thermal treatment method at 160 °C for only one minute, which denoted as fast reduced GO membrane (FRGO). Surprising, the FRGO membrane represents high ion sieving ability and ultrahigh water/ions selectivity, compared with other reduced GO membranes with similar average interlayer spacings, and even superior to most of GO-based membranes reported in literature. Building on these findings, we provide a new light on fabricating of energy- and environment-related high desalination performance of GO-based membranes as well as a new insight into the transport mechanism within 2D laminar nanochannels.

Critical Flux and Fouling Analysis of PVDF-Mixed Matrix Membranes for Reclamation of Refinery-Produced Wastewater: Effect of Mixed Liquor Suspended Solids Concentration and Aeration

“…By considering the fouling mechanisms, a strong form of critical flux was developed to discriminate no-fouling conditions (whereas R m is only the resistance in Equation (1)) from fouling conditions, where other resistances (R c ) also apply. The form of critical flux can define the application of resistances [19].…”

“…By considering the fouling mechanisms, a strong form of critical flux was developed to discriminate no-fouling conditions (whereas Rm is only the resistance in Equation ( 1)) from fouling conditions, where other resistances (Rc) also apply. The form of critical flux can define the application of resistances [19]. To calculate the critical flux values, the experimental flux-steps were the following: (1) the filtration begins with a 30 min step duration at a low flux (10 to 20 L/m 2 h); (2) at the end of this step (after 30 min), the permeate flux is increased; (3) this step is repeated until the TMP does not remain constant at a constant permeate flux; (4) critical flux is then achieved.…”

“…These are the average TMP and the rate of TMP increase (dTMP/dt). The critical flux was assumed to be the flux at dTMP/DT ≥ 0.5 [16,19].…”