A brief concept on the physical remediation of microplastics and nanoplastics from water environment

The harmful effects of microplastics (MPs) and nanoplastics (NPs) on aquatic ecosystems, which negatively impact human health, have raised considerable concerns about these contaminants in many water bodies. Their small size and distributed nature make them difficult to remove from the water. Filtration, coagulation and flocculation, and centrifugation are a few examples of physical remediation techniques that have drawn interest for their ability to handle the task. This review summarizes that physical remediations like advanced filtration, coagulation-flocculation, centrifugation, magnetic separation, ultrasonication, and electrostatic separation can achieve high removal rates for MPs and, to a lesser extent, NPs. The performance of these methods is influenced by particle size, shape, and polymer type, as well as by operational conditions and water matrix complexity. Membrane fouling and clogging reduce efficiency and increase maintenance costs. Coagulation generates sludge that must be safely managed. High-energy processes like ultrasonication contribute to carbon footprints. Conventional techniques have proven large-scale applicability, with removal efficiencies often exceeding 90%, while hybrid systems can push removal beyond 95% for MPs. NPs remain more challenging to capture, requiring process optimization, targeted pre-treatment, materials recovery, advancing hybrid treatment designs, minimizing operational costs, and integrating renewable energy sources.