Microplastic Pollution in the Environment: A Chemical Engineering Perspective on Sources, Fate, and Mitigation Strategies

Microplastic pollution is a defining environmental crisis of the Anthropocene, threatening ecosystems and human health due to its persistence and global dispersion. This review synthesizes current knowledge through a chemical engineering framework, analyzing the contaminant's lifecycle from formation and environmental fate to detection and removal. We systematically evaluate conventional and advanced mitigation technologies, highlighting the potential of engineered adsorbents (e.g., functionalized sponges, biochar) for targeted capture while underscoring the limitations of current wastewater treatment for nano-plastics. The analysis extends beyond end-of-pipe solutions to underscore the imperative for sustainable polymer design and circular economy systems, where biodegradable polymers and chemical recycling must be integrated. Crucially, we identify techno-economic analysis (TEA) and life-cycle assessment (LCA) as essential, yet underdeveloped, tools for quantifying the true cost and sustainability of management strategies. The synthesis concludes that addressing microplastic pollution requires the integrated application of chemical engineering principles across molecular, process, and system scales, and it identifies key research priorities in advanced material design, standardized analytics, hybrid treatment processes, and comprehensive impact modeling.