Improving permeability and fouling resistance of GO hydrophilic/hydrophobic Janus membrane by polyether amine crosslinking for membrane distillation of dye wastewater

Abstract

Graphene oxide (GO) modification is promising to increase vapor flux and antifouling properties of hydrophobic membranes in membrane distillation for wastewater treatment. However, the acid bonding of GO with dyes impedes its wide application in dye wastewater treatment. In this study, polyether amine D400 was used to modify hydrophilic GO layer of Janus membrane. The GD3/PTFE composite membrane (GO and D400 mass ratio of 1:2) demonstrated the best water flux and antifouling performance for methyl orange (MO) containing 3.5 wt% NaCl. The flux was increased by 170.3%− 228.9% compared to PTFE pristine membrane and the flux decline due to fouling was decreased by 41.3%− 60.8% to GO/PTFE membrane. The observed increase in the longitudinal thermal conductivity of the cross-linked GO layer suggests that the enhanced permeability is attributed to improved heat transfer resulting from the higher density of GO nanosheets. Acid bonding of GO layer with dye molecular is weakened and electrostatic repulsion is also increased, leading to the excellent antifouling performance. This study indicate that polyether amine crosslinking is promising method for modification of GO composite membrane for dye wastewater treatment.