Assessing ecological risk of organophosphate esters released from sediment with both of total content and desorbable content

Qinya Fan; Xinqing Zou; Jianhua Gao; Yu Cheng; Chenglong Wang; Ziyue Feng; Yongcheng Ding; Chuchu Zhang

doi:10.1016/j.scitotenv.2020.144907

Assessing ecological risk of organophosphate esters released from sediment with both of total content and desorbable content

Sci Total Environ. 2021 Jun 10:772:144907. doi: 10.1016/j.scitotenv.2020.144907. Epub 2021 Feb 4.

Authors

Qinya Fan¹, Xinqing Zou², Jianhua Gao³, Yu Cheng³, Chenglong Wang³, Ziyue Feng³, Yongcheng Ding³, Chuchu Zhang³

Affiliations

¹ School of Geography and Ocean Science, Nanjing University, Nanjing 210023, China; Ministry of Education Key Laboratory for Coast and Island Development, Nanjing University, Nanjing 210023, China; Collaborative Innovation Center of South China Sea Studies, Nanjing University, Nanjing 210023, China.
² School of Geography and Ocean Science, Nanjing University, Nanjing 210023, China; Ministry of Education Key Laboratory for Coast and Island Development, Nanjing University, Nanjing 210023, China; Collaborative Innovation Center of South China Sea Studies, Nanjing University, Nanjing 210023, China. Electronic address: zouxq@nju.edu.cn.
³ School of Geography and Ocean Science, Nanjing University, Nanjing 210023, China.

PMID: 33770857
DOI: 10.1016/j.scitotenv.2020.144907

Abstract

This study introduced fractions (labile, stable-adsorbed, tight-adsorbed fractions) of organophosphate esters (OPEs) into ecological risk assessment to evaluate the potential risks of organophosphate esters that released from sediment, and conduct a case study to verify it. The content of desorbable fractions was get from adsorption-desorption experiments. Adsorption process can be divided into fast sorption, gradual sorption, and final equilibrium stage, and labile, stable-adsorbed, tight-adsorbed fractions were formed during adsorption. Approximately 86.21% labile, 73.41% stable-adsorbed, and 43.01% tight-adsorbed TPhP-D can be desorbed from sediments in desorption experiments. According to the results, the value of hazard quotient (HQ) that calculated by desorbable fractions reduced by 13.88% than HQ calculated by the sum of fractions, and result of 29.76% decrease for ∑HQs. The isotherm results demonstrated that the contents of labile and stable-adsorbed fractions increased faster than tight-adsorbed fraction when the concentration of contaminant in water increased from 50 to 400 μg/L, which means ecological risk in areas with high concentration of contaminants are higher than the discreet value. In case study, an additional hotspot was found in areas, where characterized with high proportion of labile fraction, when ecological risk was calculated by desorbable fractions. Indicating that revised ecological risk assessment takes both of total content and desorbable content into consideration.

Keywords: Desorbable fraction; Ecological risk; Organophosphate ester.