Treatment of MB wastewater with a Fe–RGO/TiO2/PTFE photocatalytic composite membrane

Abstract

A novel Fe–RGO/TiO₂/PTFE photocatalytic composite membrane was developed for the purification of MB wastewater. The properties of the prepared membranes were characterized using XRD, SEM, FT-IR spectroscopy, the BET method, and water contact angle, membrane flux, and BSA adsorption measurements. The photocatalytic properties of the surface-modified membranes were investigated in filtration experiments using MB as a representative organic contaminant. The results of the experiments showed that the Fe–RGO/TiO₂ particles were securely loaded onto the surface of the PTFE membrane, demonstrating excellent chemical stability of the composite membrane. The incorporation of Fe³⁺ inhibited the agglomeration of TiO₂ particles and enhanced the photocatalytic reaction rate. The introduction of RGO could broaden the photoresponsive range of TiO₂, increase the specific surface area of the photocatalyst, introduce a large number of hydrophilic groups to enhance the hydrophilicity of the composite membrane, and subsequently increase the membrane flux. The MB wastewater was treated with the Fe–RGO/TiO₂/PTFE composite membrane system for 3 h and the removal rate of MB reached 95.8% and 60.1% under UV and visible light, respectively. Reaction kinetic analysis indicated that the removal process of MB wastewater by Fe–RGO/TiO₂/PTFE involves an adsorption–degradation–filtration synergy mechanism.