Biodegradable Nanomaterials For Removal Of Microplastic In Aquatic Environments: A Critical Review

Abstract

Biodegradable nanomaterials have emerged as a sustainable and effective class of adsorbents for microplastic remediation in aquatic ecosystems. This critical review examines the latest advances in biopolymer-based adsorbents—including chitin–cellulose foams, magnetic biochar composites, nanocellulose aerogels, biosurfactant-enhanced membranes, and cattail-fiber sorbents. We analyze removal efficiencies, adsorption mechanisms (hydrogen bonding, electrostatic interactions, π–π stacking, hydrophobic interactions), regeneration potential, and resilience in complex water matrices. Highlighting key innovations such as the supramolecular self-assembled chitin–cellulose (Ct-Cel) foam achieving up to 99.9 % removal and sustained performance over multiple cycles, as well as magnetic lignin biochar systems offering combined adsorption and catalytic degradation, this review identifies performance trends and design principles. Challenges including scale-up feasibility, long-term stability, and environmental fate are critically assessed. The review concludes by proposing future directions: integration of multifunctional biodegradable nanomaterials into hybrid treatment systems, lifecycle assessments, and enhancing selectivity for diverse microplastic types to drive real-world application.