Treatment of Plastics and Microplastics Present in Sewage Effluent

Abstract

Microplastics are tiny plastic particles less than five millimeters in size, and they are now found almost everywhere in aquatic environments. A major source of these particles is urban sewage systems, which act as transport channels for microplastics entering rivers, lakes, and oceans. Because microplastics are durable and capable of absorbing harmful pollutants, they pose serious risks to both the environment and public health. Unfortunately, current wastewater treatment plants (WWTPs) are not designed to effectively remove them, especially particles smaller than a micron. This chapter discusses the classification, sources, and fate of microplastics in sewage effluents, along with their environmental and health hazards. It also examines existing and emerging treatment technologies such as membrane filtration, coagulation-flocculation, magnetic separation using functionalized nanocomposite materials, and biodegradation. Case studies on treatment performance, detection methods, regulatory approaches, and the role of circular economy strategies are also included. Finally, the chapter provides practical recommendations for upgrading treatment facilities and outlines policy directions aimed at achieving sustainable reductions in microplastic pollution.