Distribution Characteristics, Sources, and Risks of Organophosphate Triesters and Diesters in the Qiantang River, Hangzhou

• • ΣOPEs in water ranged 31.5–98.9 ng/L and in sediment 10.8–341 ng/g dw, indicating moderate-low pollution; Σdi-OPEs in water 2.19–104 ng/L and sediment 0.437–106 ng/g dw, with TCIPP/TCEP dominant in water and TEHP in sediment. • • Source analysis (correlation and PCA) linked OPEs/di-OPEs to industrial and agricultural activities, including household, tire, and plastic production, providing a basis for targeted emission controls. • • Ecological risk assessment showed negligible risk for most OPEs in water, but TEHP and EHDPP in sediment posed high risk to crustaceans, and TPHP to algae, with combined toxicity at multiple sites requiring mitigation. • • The study provides baseline data for 19 OPEs and 8 di-OPEs in a major Chinese river, supporting regulatory monitoring and risk management of these emerging contaminants.