Microplastic Pollution: Sources, Degradation Mechanisms, Analytical Advances, and Mitigation Strategies for Environmental Sustainability

Microplastic pollution has emerged as a critical global environmental challenge, with an estimated 1.7 million tonnes of plastic waste entering the oceans annually and microplastic concentrations reaching up to 4.34 particles per liter in drinking water. This review provides a comprehensive analysis of microplastic sources, degradation mechanisms, analytical methodologies, and mitigation strategies. The pathways through which microplastics enter aquatic and terrestrial environments are examined, emphasizing their persistence and bioaccumulation risks. The review details key degradation processes including physical fragmentation, photodegradation, chemical oxidation, and microbial biodegradation, with a comparative evaluation of their effectiveness and environmental significance. Additionally, we assess state-of-the-art detection techniques, such as Fourier-transform infrared (FTIR) and Raman spectroscopy, which are capable of identifying microplastics down to 100 nm. Current mitigation efforts, including advanced wastewater treatment technologies (membrane bioreactors, electrocoagulation), bio-based sorbents for microplastic removal, and global regulatory measures such as the EU Microplastics Restriction Proposal (2023), are discussed. By synthesizing recent developments and identifying critical research gaps, this review provides a roadmap for future innovations in microplastic pollution management, emphasizing the need for interdisciplinary solutions to minimize environmental and human health risks.