An overview of the occurrence and distribution of plastics in wastewater treatment plants and the necessity of developing up-to-date management strategies

Although studies suggest that wastewater treatment plants (WWTPs) are the main pathway for plastics into receiving waters, studies on the origin and fate of plastics entering WWTPs are imprecise and largely unexplored. The analysis of plastics in samples from WWTPs is also a relatively young and growing field compared with the marine environment. Furthermore, recent studies have shown that plastics are not uniformly distributed in WWTPs due to environmental factors and the inherent properties of plastics. Accordingly, this review article attempts to describe the current state of knowledge on plastic pollution in WWTPs and identify future research areas. In particular, this study describes the sources of plastics entering WWTPs and the analytical techniques used for the occurrence and properties of plastics in WWTPs. It also defines the role of these plastics as a possible source of microplastics and discusses the problems they can cause in WWTPs. The factors that can influence the variations in the number of plastics are defined. Furthermore, the policy needs for managing plastic pollution as a contribution to achieving the United Nations Sustainable Development Goals are assessed.