Advances in polystyrene nanoplastic remediation: A review of detection methods, toxicity, removal strategies, and economic insights

Plastic waste contamination in marine environments is a critical global issue arising from inadequate waste management, littering, industrial activities, and illegal dumping. Over time, plastic debris fragments into micro- and nano-sized particles, with nanoplastics posing severe risks due to their mobility, persistence, and hazardous impacts on aquatic organisms and plants. This paper addresses the critical environmental issue of plastic waste contamination in the marine ecosystem, with a particular focus on the risk posed by nanoplastics. Here, we emphasized recent advances and novel treatment processes with strong potential for integration into existing wastewater treatment systems, facilitating ease of adoption and rapid technological transfer. Detection and quantification methods, including spectroscopy, microscopy, and microfluidic devices, are discussed alongside the toxicological effects of nanoplastic on microorganisms, plants, and aquatic organisms. Among the reviewed methods, the highest removal efficiencies were achieved using a polyaluminium chloride coagulant, which gained 99.4% separation; catalyst-supported ozonation removed 96.7%; and Chlorella vulgaris-based bioreactors degraded 98.83% of nanoplastics. This work aims to highlight the need for a multifaceted approach that combines technological innovation, environmental monitoring, and techno-economic assessment to ensure the large-scale, cost-effective implementation of nanoplastic remediation within existing water treatment facilities.