Microplastics in municipal wastewater treatment plants in Turkey: a comparison of the influent and secondary effluent concentrations

Wastewater treatment plants are one of the primary pathways through which microplastics enter aquatic environments. In this study, we have determined the microplastic concentrations of the influent and secondary effluent water of two wastewater treatment plants in Turkey. For this purpose, we have taken samples of the influent and effluent water of Seyhan and Yüreğir wastewater treatment facilities for 6 days in August 2017 and determined their microplastics’ content both visually and using μ-Raman spectroscopy. The results showed that the influent of the wastewater treatment contained 1 million–6.5 million particles per day, while the effluent contained 220,000–1.5 million particles per day. The removal rate of microplastics was found to be between 73 and 79%. In total, seven different types of polymers were detected. The most frequently observed polymer type was polyester.