Investigating the Presence and Distribution of Microplastics in Wastewater Treatment Plants Systems

Abstract

Microplastic is a highly concerning emerging contaminant with the significant increase of municipal waste along with the elevating growth of population. Wastewater is one of the main routes contributing to the persistent microplastics presence in the environment since it originates from domestic, industrial, and even agricultural wastewater. These facilities are increasingly identified as potential contributors to the release of microplastics (MPs) into the environment. This study aims to examine the occurrence and distributions of MPs in both the influent and effluent of two districts sewage treatment plant (STP) in Kota Kinabalu (UMS STP) and regional sewage treatment plant Penampang (RSTP) Sabah Malaysia. The results showed that the abundance of MPs in UMS STP was higher in both influents and effluents than RSTP. The average size of MPs found varied from 1.0 mm to 125 µm being the most abundant. Microplastics 2.0 mm is higher in influents, while effluents exhibit higher concentrations of smaller particles (63 µm). In terms of microplastic morphology, fragments were identified as the most predominant shape in the sampled materials from both sewage treatment plants (STPs), whereas microplastic beads were the least frequently detected. The distribution of colours across the influent and effluent samples was consistent, with a variety of colours identified, though green, blue, and red predominated. Polymer analysis revealed a diverse array of microplastic types present in the samples, including polypropylene (PP), nylon (PA), and polyethylene terephthalate (PET/PETE), indicating a variety of sources and characteristics of the microplastics entering the treatment systems. These polymer types were found in both influent and effluent, suggesting that certain microplastics may persist through the treatment process. Overall, this study offers a comprehensive analysis of the physical and chemical properties of microplastics in wastewater treatment systems, providing valuable insights into their distribution, persistence, and the potential implications for the fate of microplastics within wastewater treatment processes. The findings contribute to a better understanding of microplastic behavior, highlighting key factors influencing their occurrence and removal efficiency in sewage treatment plants.