Microplastics and organic contaminants mixed contaminants
The primary goal of this study is to elucidate how the physicochemical properties of microplastics (MPs) specifically polymer type (polyethylene vs. polypropylene) and particle size influence the microbial degradation of co-occurring organic contaminants with contrasting hydrophobicity, using the hydrophilic antibiotic sulfamethoxazole (SMX) and the hydrophobic antimicrobial triclosan (TCS) as model pollutants. This investigation is motivated by the critical knowledge gap regarding whether MPs act as passive carriers that simply sequester pollutants or as active interfaces that either promote or hinder bioremediation processes in aquatic environments. By systematically comparing degradation kinetics, microbial community shifts, sorption behavior, and MP surface weathering across a range of environmentally relevant hotspot concentrations, the study aims to establish a predictive, hydrophobicity-driven framework for assessing MP-pollutant-microbe interactions. The relevance of this work lies in its direct implications for wastewater treatment design, environmental risk assessment, and regulatory policy, as it moves beyond the simplistic view of MPs as inert vectors and instead positions them as conditional regulators whose impact on pollutant fate is dictated by an interplay of polymer chemistry, particle size, and contaminant properties. These findings are essential for developing targeted mitigation strategies in an era of increasing plastic and pharmaceutical pollution.