Abundance, Characteristics, and Removal of Microplastics in Wastewater Treatment Plant located in Southwest China

Due to the contamination of wastewater from urban and industrial areas with microplastics (MPs), Wastewater Treatment Plants (WWTPs) act as potential sources and contributors of MPs. The WWTP located in Leshan, Western China, was selected as the subject of the investigation. The abundance, characteristics, and removal of MPs at different wastewater treatment units were investigated. The results showed that the abundance of MPs in the influent was 267.74 n/L, while that in the effluent was 68.34 n/L. The total removal efficiency of MPs was 74.48%. MPs within the 0.05-0.3 mm size range had the highest average distribution (around 40%) in different treatment units. Fibers were the dominant morphology among the MPs found in the wastewater samples, accounting for 69.99% to 79.18%, followed by microbeads (8.27%–17.96%) and films (4.03%–6.44%). White and transparent MPs were the dominant colors found throughout the treatment process. The major types of MPs polymers identified included PET, PVC, PA, PS, PP, and PE. PET was the most dominant polymer type among the total MPs.