EMERGING CONTAMINANTS IN WATER: A REVIEW OF MICROPLASTICS AND THE FORMATION OF DISINFECTION BYPRODUCTS

Abstract

The presence of microplastics (MPs) in aquatic environments has raised growing concern due to risks to health and the environment, particularly their interference with drinking water treatment and the formation of disinfection by-products (DBPs). This review synthesizes studies published between 2019 and 2024 on interactions between MPs and disinfectants—chlorine, chlorine dioxide, ozone, and ultraviolet radiation. Evidence indicates that MPs act as reactive surfaces, vectors for contaminants, and indirect precursors, contributing to toxic DBPs such as trihalomethanes, haloacetic acids, and nitrosamines. Physicochemical aging within treatment and distribution systems enhances leaching of additives and oxidation products, which participate in complex reaction networks. Effects vary with polymer type, oxidant dose and contact conditions, and the presence of dissolved organic matter. Key gaps include the lack of standardized methods for quantifying MPs in treated water, the scarcity of data on nanoplastics, and limited long-term risk assessment. Overall, MPs in water treatment should not be overlooked, as they represent an emerging pathway for human and environmental exposure to DBPs. The review underscores the need to integrate MP removal research, robust analytical methods, and evidence-based policies to address this challenge in the context of drinking-water safety.