Bioadsorbents for removal of microplastics from water ecosystems: a review

This review analyzes 206 research papers from 2016-January 2024 to explore recent advances in bioadsorbent design and application for microplastic removal from water systems. The study examines the sources and ecological impacts of microplastics, then evaluates the most studied bioadsorbents including biochar (51.9%), biomass-derived activated carbon (7.4%), synthetic sponges/aerogels (25.9%), and graphene-based materials (14.8%). The review critically analyzes factors influencing MP adsorption by these materials, including MP type and size, adsorbent properties, and experimental conditions. Reported removal efficiencies ranged from 31% to 100%, with polystyrene being the most common test polymer. The paper discusses the intricate mechanisms of MP-bioadsorbent interaction and highlights key challenges and future research directions for optimising and scaling up bioadsorbent-based MP removal, acknowledging the early stage of this promising and sustainable approach.