Removal of microplastics in water: Technology progress and green strategies

Abstract

• Major technology progress for the removal of MPs was summarized and compared. • Filtration approach has various removal efficiency, but frequent membrane fouling. • Adsorption, magnetic separation and oxidation treatment have secondary pollution risks. • Biodegradation is environmentally friendly, but often of a low degradation efficiency. • We propose green strategies including low pollutant technology and integrated approaches. Microplastics (MPs) are globally distributed in aquatic environments, and become a growing threat to the ecosystem. It is urgently needed to develop effective technologies to remove MPs from water. In this review, we summarized progress in major technologies for the removal of MPs. Currently, multiple technologies for MPs removal have been developed including physical, chemical, and biological approaches. Filtration technology has a various removal efficiency, but a relatively high cost due to membrane fouling and replacing new filter membranes. The approach of adsorption and magnetic separation is a simple removal method; however, additive sorbents may cause secondary pollution. There is a similar problem of chemical residua in coagulation and oxidation treatment. In contrast, biodegradation and bioreactors are often of a low degradation efficiency. Then, existing removal technologies were comparatively analyzed in several aspects, especially practical efficiency and environmental impacts. Finally, green strategies for plastic abatement were proposed, including zero pollutant removal technology, integrated environmentally friendly approaches, recycling use of conventional plastic, and developing biodegradable plastic in the future.