Removal of microplastics in wastewater by ceramic microfiltration

Abstract

Microplastic (MP) pollution is a growing global concern affecting environmental water quality. Although primary and secondary treatment processes in conventional wastewater treatment plants (WWTPs) efficiently remove MPs, MPs <20 μm across are not removed effectively. The quality of final effluent should be enhanced by applying a tertiary treatment for reducing MP discharge from WWTPs. This study evaluated the effectiveness of ceramic membranes for this. Removal of MPs was assessed at laboratory scale by cross-flow filtration of a secondary wastewater effluent. The activated sludge process at a wastewater treatment plant removed MPs at moderate to high rates (45 %–98 %), and the ceramic membranes further removed >72 % of MPs. Although the activated sludge process removed variable rates of MPs, the total rates of removal by both processes was >96 %. This result suggests that the ceramic MF membrane treatment will contribute to stable MP removal.