title: Sorption of endocrine disrupting chemicals by condensed organic matter in soils and sediments.
abstract: Sorption of 17alpha-ethinyl estradiol (EE2) and bisphenol A (BPA) by nonhydrolyzable carbon (NHC), black carbon (BC), and bulk soils and sediments was examined. All sorption isotherms were nonlinear and fitted both Freundlich and Dubinin-Ashtakhov (DA) models. The single-point organic carbon (OC)-normalized distribution coefficient (K(OC)) of EE2 for the isolated NHC and BC was 2.7-4.8 times and 5.4-12.9 times greater, respectively, than that of the bulk samples. However, no clear trend in BPA K(OC) values was observed. Based on the contribution of soil/sediment organic matter (SOM) fractions to the overall sorption of BPA or EE2 by the bulk samples, condensed SOM (NHC and BC) generally played a dominant role to the overall sorption. The BPA adsorption capacity (Q(OC)(0)) from the DA model was higher than that of EE2 on NHC and there was obvious difference in isotherm nonlinearity (n) between EE2 and BPA. These results suggest that BPA may have more access to the pore sites of NHC samples than EE2. The pi-pi bonds formed between BPA and NHC or BC may be stronger than that between EE2 and NHC or BC. This would be attributed to the fact that BPA has two benzene rings, and can also be used to explain the difference in hexadecane-water partition coefficient (K(HW))-normalized K(OC) values (K(OC)/K(HW)) of BPA and EE2 after factoring out the hydrophobic effect. These findings could be useful for predicting fate and ecological risks of endocrine disrupting chemicals (EDCs) (e.g., EE2 and BPA) in natural environments especially when soils or sediments become receptors for EDCs.
authors.affiliation: State Key Laboratory of Water Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Sun
authors.forename: Bo
authors.initials: B
authors.lastname: Gao
authors.forename: Zheyun
authors.initials: Z
authors.lastname: Zhang
authors.forename: Guixiang
authors.initials: G
authors.lastname: Zhang
authors.forename: Xitao
authors.initials: X
authors.lastname: Liu
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhao
authors.forename: Baoshan
authors.initials: B
authors.lastname: Xing
mesh_terms: D000042:Absorption; D000327:Adsorption; D001559:Benzhydryl Compounds; D002244:Carbon / Q000737:chemistry; D052244:Endocrine Disruptors / Q000737:chemistry*; D052918:Environmental Restoration and Remediation / Q000379:methods; D004997:Ethinyl Estradiol / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry*; D008956:Models, Chemical; D010636:Phenols / Q000737:chemistry*; D012987:Soil; D012989:Soil Pollutants / Q000737:chemistry*; D053260:Soot / Q000737:chemistry; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D002244:Carbon; D052244:Endocrine Disruptors; D004997:Ethinyl Estradiol; D010636:Phenols; D012987:Soil; D012989:Soil Pollutants; D053260:Soot; C006780:bisphenol A; D000098826:Bisphenol A Compounds