Determination of polyoxymethylene-water partition coefficients for diverse organophosphate esters (OPEs) and prediction of the free-dissolved OPEs in OPE-contaminated soil

Zifei Qin; Renjie Bian; Liang-Ying Liu; William A Stubbings; Xiaoli Zhao; Fangbai Li; Fengchang Wu; Shaorui Wang

doi:10.1016/j.scitotenv.2023.162528

Determination of polyoxymethylene-water partition coefficients for diverse organophosphate esters (OPEs) and prediction of the free-dissolved OPEs in OPE-contaminated soil

Sci Total Environ. 2023 Jun 1:875:162528. doi: 10.1016/j.scitotenv.2023.162528. Epub 2023 Mar 8.

Authors

Zifei Qin¹, Renjie Bian², Liang-Ying Liu³, William A Stubbings⁴, Xiaoli Zhao⁵, Fangbai Li², Fengchang Wu⁶, Shaorui Wang⁷

Affiliations

¹ National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China; School of Mechanical Engineering, Jiangnan University, Wuxi 214122, China.
² National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China.
³ Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China.
⁴ School of Geography, Earth, and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK.
⁵ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
⁶ National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China; School of Mechanical Engineering, Jiangnan University, Wuxi 214122, China; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
⁷ National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China. Electronic address: wangshaor@126.com.

PMID: 36894077
DOI: 10.1016/j.scitotenv.2023.162528

Abstract

Increasing attention on the estimation of bioavailability of organophosphate esters (OPEs) in soil or sediment has urged the development of techniques to measure soil-/sediment-associated porewater concentrations of OPEs. In this study, we investigated the sorption dynamics of 8 OPEs to polyoxymethylene (POM) spanning one order of magnitude of aqueous OPE concentrations and proposed POM-water partitioning coefficients (K_pom/w) for OPEs. The results showed that the K_pom/w values were mainly affected by the hydrophobicity of OPEs. OPEs with high solubility preferentially partitioned into the aqueous phase indicated by the low log K_pom/w values; while lipophilic OPEs were observed to be taken up by POM. The concentration of lipophilic OPEs in the aqueous phase had a strong impact on their sorption dynamics on POM, with higher aqueous concentrations accelerating the sorption dynamics and shortening the time for equilibration. We proposed that the required time to reach equilibration for targeted OPEs should be 42 d. The proposed equilibration time and K_pom/w values were further validated by applying POM to soil artificially contaminated with OPEs to measure OPEs soil-water partitioning coefficients (K_s). The variations of K_s among soil types implied the need to elucidate the effects of soil properties and chemical properties of OPEs on their distribution between soil and water in the future.

Keywords: Equilibration time; Polyoxymethylene (POM); Soil-water partitioning coefficients; Sorption dynamic.