title: A diffusive gradients in thin-films technique for the assessment of bisphenols desorption from soils.
abstract: Desorption/adsorption of bisphenols (BPs) in soils affects their mobility and availability. However, the kinetics of these processes have not been well studied, due to the lack of appropriate means of measurement. Diffusive gradients in thin-films (DGT) technique can assess kinetic processes in soils and have recently been developed for measuring three BPs (BPA, BPB and BPF). DGT was deployed for 2.5h to 20 d in five soils with different soil properties. Non-linear increase in mass accumulation by DGT with time indicated poor resupply of BPs from soil solid to solution phase. By fitting the data with DIFS (DGT-induced fluxes in soils) model, values for the labile partition coefficient (Kdl), response time (tc) and rates of exchange (k1and k-1) of BPs between soil solid and solution phases were obtained. The derived values of Kdlshowed that most of the BPs in the soil could participate in labile exchange. Average response times of 1-2h implied that the supply of BPs to DGT was limited by their desorption rate. Soils with more binding sites (higher DOM, CEC and Fe oxides) could resupply BPs more quickly, highlighting the danger of just considering partition effects.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China.
authors.forename: Dong-Xing
authors.initials: DX
authors.lastname: Guan
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China.
authors.forename: Jian-Lun
authors.initials: JL
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China. Electronic address: esluojun@nju.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Luo
authors.affiliation: Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK.
authors.forename: William
authors.initials: W
authors.lastname: Davison
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China; Soil and Water Science Department, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Lena Q
authors.initials: LQ
authors.lastname: Ma
keywords: Bisphenols; DGT-induced fluxes in soils (DIFS); Desorption/adsorption; Diffusive gradients in thin-films; Labile partition coefficient