Seasonal variation and partitioning of endocrine disrupting chemicals in waters and sediments of the Pearl River system, South China

Endocrine disrupting chemicals (EDCs) were seasonally investigated in surface water, suspended particulate matter, and sediments of the Pearl River Delta (PRD), South China. EDC concentrations in the surface water were generally higher in the summer than in winter. The surface water in the investigated rivers was heavily contaminated by the phenolic xenoestrogens. Moreover, the in-situ log K_soc and log K_poc values and their regression with log K_ow in the field experiments suggest that binding mechanisms other than hydrophobic interaction are present for the sedimentary organic carbon and particulate organic carbon (SOC/POC). The logK_soc–logK_ow and logK_poc–logK_ow regression analyses imply that higher complexity of nonhydrophobic interactions with EDCs is present on the SOC samples comparing with the POC samples, which is related to their different sources. - Highlights: • Endocrine disrupting chemicals were generally higher in the summer than in winter. • The investigated river water was heavily contaminated by phenolic xenoestrogens. • Sediment-water partitioning values (logK_soc and logK_poc) are related with log K_ow. • Sediment binding mechanisms other than hydrophobic interaction are important. - The higher than predicted partitioning coefficients were attributed to several factors such as long contact time and heterogeneity of POC and SOC.