Electrokinetic-assisted filtration for fast and highly efficient removal of microplastics from water

Abstract

Among engineered degradation and separation methods for microplastics (MPs) removal from aquatic environments, membrane filtration (MF) relying on a size exclusion mechanism has shown potential for effective treatment of various-sized MPs ranging from submicron to a few millimeters. However, basic concerns about MF involved in an inherent efficiency-flux trade-off and membrane fouling raise questions about its practical applicability. Here, an electrokinetic-assisted filtration fulfilled by introducing electrokinetic assistance into physical filtration is proposed as a new candidate able to address the concerns of MF. Our hybrid filtration system demonstrates outstanding filtration performance for tiny plastic specks (a removal efficiency of > 99.9 % and a flux of similar to 10,000 L m(2) h(-1)) only with a coarse physical filter, by electrokinetically arresting MPs passing through a filter lattice. In particular, consistent filtration performance is accomplished in our system regardless of MPs' types, sizes, concentrations, and chemical compositions due to the electrokinetic assistance solely depending on MPs' electrophoretic mobility. This study provides key insights into a highly scalable electrokinetic system, offering a practical solution to successfully deal with MPs pollution prevalent in aquatic environments.