Distribution Dynamics of Phthalate Esters in Surface Water and Sediment of the Middle-Lower Hanjiang River, China

Phthalate esters (PAEs) are endocrine-disrupting chemicals that pose potential risks to human health. Water and sediments are crucial carriers and storage media for the migration and transformation of PAEs. In this study, six congeners of PAEs were measured in water and sediment samples to elucidate their spatial distribution, congener profiles, and ecological risks in the middle-lower Hanjiang River during the wet and dry seasons. The concentration of the sigma(6)PAEs ranged from 592 to 2.75 x 10(3) ng/L with an average of 1.47 x 10(3) ng/L in surface water, while the concentration of the sigma(6)PAEs ranged from 1.12 x 10(3) to 6.61 x 10(3) ng/g with an average of 2.69 x 10(3) ng/g in sediments. In general, PAE concentrations were ranked as sediment > water, and dry season > wet season. DEHP and DBP were the dominant PAEs in the middle-lower Hanjiang River in surface water and sediments. SPSS analysis showed that dissolved organic carbon (DOC) in surface water was significantly correlated with the concentration of DBP, DEHP, and the n-ary sumation (6)PAEs, while organic matter (OM) was significantly correlated with the concentration of the n-ary sumation (6)PAEs in sediments. The concentrations of PAEs were irregularly distributed and varied significantly in surface water and sediments. Compared with other regions at home and abroad, the pollution levels of surface water and sediments in the middle-lower Hanjiang River were relatively low and not enough to have a negative impact on the local water's ecological environment. However, the supervision of land-based discharge should still be strengthened.