Graphene oxide membranes for effective removal of humic acid

Abstract

Abstract2-Dimensional materials-based membranes have been considered as promising candidates for water purification. Here, we report that graphene oxide (GO) membrane can reject aquatic humic acid (HA) up to 94.2% in a 2-bar pressurized filtration process. In-depth analysis indicated that the filtration performances such as water flux and rejection rate depend on the thickness and physical structure of the membranes. The experimental study reveals that the GO membrane with a mass loading of 0.58 mg/cm2, which is approximately equivalent to 3 μm thickness, is required to reach the rejection rate of HA at 94% using 2 bar pressurized filtration method. We further confirmed the membranes’ integrity by over 98% rejection of methylene blue (MB). For practicality, we tested our membrane in tubular form by coating GO on PVDF hollow fibres, which presented similar rejection performances using vacuum filtration method while maintaining the water flux around 100 L m−2 h−1 bar−1. Graphical abstract