Synthesis of metal organic framework-based hydrogel for microplastics removal from aquatic environments

Abstract

Microplastics (MPs) pollution has emerged as a pressing global environmental problem. Current research in this field remains exploratory because there is a lack of standards, methods, and policies for the detection, removal, and regulation of MPs discharge. In this study, a series of metal–organic framework (MOFs)-incorporated hydrogels was successfully fabricated via a photo-initiated cross-linking strategy, offering a facile and efficient preparation approach applicable to the removal of diverse MPs types. Among them, ZIF–8.1@H6mg exhibited the highest MPs removal efficiencies, achieving up to 97% for polyethylene terephthalate (PET) and 98% for polyethylene (PE) in laundry wastewater, one of the main sources of MPs pollution. The material demonstrated excellent recyclability, with MPs removal efficiency only slightly decreasing to 96% after six reuse cycles. It maintained stable operation for approximately 4 h, and pre-treatment with backwashing further enhanced long-term filtration performance. Comprehensive characterization of the ZIF-8 hydrogel composites suggests that their interpenetrating network structures, zeta potential, and surface functional groups contributed to their superior performance. These findings highlight the potential of ZIF-based hydrogels as sustainable and effective materials for mitigating the growing threat of MPs pollution.