Distribution characteristics and relationship of microplastics, phthalate esters, and bisphenol A in the Beiyun River basin of Beijing.

Urban rivers are closely related to human life, and due to the widespread use of plastic products, rivers have become important carriers of pollutants such as microplastics (MP), phthalate esters (PAEs), and bisphenol A (BPA). However, our understanding of the distribution characteristics and relationships of MP, PAEs, and BPA in rivers is limited. In this study, MP, six PAEs and BPA were detected in the water and sediments of the Beiyun River basin. Polyvinyl chloride (PVC) was the most abundant type of microplastic, while di(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) were the most abundant PAEs. MP, PAEs, and BPA in both water and sediment showed positive correlations, with stronger correlations and higher pollution levels in sediment than in water. The tendency for PAE congeners to partition into sediments increased with a higher octanol-water partition coefficient (K). There was a significant positive correlation between the distribution tendency of ∑PAEs and TOC in sediments with a pearson correlation coefficient of 0.717. Rivers with more frequent human activities and higher levels of urbanization in the vicinity had a higher abundance of various pollutants and a greater diversity of MP types.