Efficient Filtration Systems for Microplastic Elimination in Wastewater

This study presents the development of a textile-based cascade filter for the removal of microplastics from an industrial laundry effluent. The cascade microfilter consists of three stages of 3D textile sandwich composite filter media, which have successively finer pores and are aimed at filtering microplastic particles down to 1.5 µm. Polypropylene fabrics with pore sizes of 100, 50 and 20 µm and 3D warp-knitted fabrics with high porosity (96%) were used. Filtration tests were carried out with polyethylene model microplastic particles at a concentration of 167 mg/L. To regenerate the filter and restore its filtration performance, backwashing with filtered water and compressed air was applied. Field trials at an industrial laundry facility and a municipal wastewater treatment plant confirmed high removal efficiencies. The 3D textile sandwich structure promotes filter cake formation, allowing extended backwash intervals and the effective recovery of filtration capacity between 89.7% and 98.5%. The innovative use of 3D textile composites enables a high level of microplastic removal while extending the filter media lifetime. This makes a significant contribution to the reduction in microplastic emissions in the aquatic environment. The system is scalable, space and cost efficient and adaptable to various industrial applications and is thus a promising solution for advanced wastewater treatment.