Distribution Characteristics, Sources, and Risks of Organophosphate Triesters and Diesters in the Qiantang River, Hangzhou
This study investigated the occurrence, distribution, sources, and ecological risks of 19 organophosphate triesters (OPEs) and 8 diesters (di-OPEs) in surface water and sediments from the Hangzhou section of the Qiantang River. Samples were analyzed using liquid chromatography-high resolution mass spectrometry. Concentrations of ΣOPEs in water ranged from 31.5 to 98.9 ng/L, and in sediments from 10.8 to 341 ng/g dry weight (dw). Σdi-OPEs ranged from 2.19 to 104 ng/L in water and 0.437 to 106 ng/g dw in sediments, indicating moderate to low contamination. TCIPP and TCEP dominated OPEs in water, while TEHP was the predominant OPE in sediments. DBP was the major di-OPE in water, and DPHP in sediments. Source apportionment via correlation and principal component analysis identified industrial production and human activities, including household, tire, plastic manufacturing, and agricultural practices, as primary sources. Ecological risk assessment revealed negligible risks for most OPEs in water, but notable risks in sediments: TEHP and EHDPP posed risks to crustaceans, and TPHP to algae. Moreover, combined toxicity at multiple sediment sampling sites raised concern, warranting further attention.