Levels and Distribution of Organophosphate Esters (OPEs) in Typical Megacity Wetland Park Landscape Water Bodies in Southwest China

Abstract

Human activities have led to the release of organophosphate esters (OPEs) into the environment. This study aims to investigate the levels and partitioning of OPEs in surface water, suspended particulate matter (SPM) and sediments of landscape waters across eleven parks in the city of Chengdu, a megacity in Southwest China. The average concentration of Σ6OPEs in the SPM samples (median: 2.94×103 ng/L, 6.88×104 ng/g dw) was 1-3 orders of magnitude higher than that in the surface water (median: 359 ng/L) and sediment (median: 82.8 ng/g) samples. Tri-n-butyl phosphate (TnBP), tris-(2-chloroethyl)-phosphate (TCEP) and trichloropropyl phosphate (TCIPP) were the primary OPE pollutants in the surface water and SPM samples, while TnBP, tris-(2-butoxyethyl) phosphate (TBEP) and tris-(2-ethylhexyl) phosphate (TEHP) predominated the sediment samples. The higher log Koc values of OPEs in park landscape water bodies than other studies in the present study could be explained by the OPE properties (foc, Kow, degradability) and the environmental conditions (the input sources and the hydraulic retention time, etc.).