Microplastics and Nanoplastics in the Environment: Chemical and Biochemical Strategies for Effective Degradation

Abstract Microplastics (<5 mm) and nanoplastics (<1 µm) are persistent environmental pollutants formed from fragmentation of synthetic polymers. Their small size, high surface area, and resistance to natural breakdown allow accumulation across ecosystems and potential transfer of contaminants, raising ecological and human health concerns. Conventional waste management fails to address diffuse particles, driving research toward advanced degradation methods. This review evaluates chemical (photodegradation, pyrolysis, advanced oxidation), biochemical (enzymatic, microbial), and hybrid strategies. Chemical methods achieve rapid chain scission but often produce secondary pollutants and incomplete mineralization. Biochemical approaches offer specificity and potential full mineralization, though limited by crystallinity and kinetics. Hybrid systems combining oxidative pretreatment with enzymatic/microbial degradation show the highest promise. Emerging tools (enzyme engineering, AI, computational modeling) and environmental safety considerations are discussed. Scalability, cost, field validation, and standardized analytics remain major challenges.