State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China.
J Hazard Mater. 2017 Jun 5;331:321-328. doi: 10.1016/j.jhazmat.2017.02.053. Epub 2017 Feb 27.
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 (K), response time (t) and rates of exchange (k and k) of BPs between soil solid and solution phases were obtained. The derived values of K showed 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.
双酚（BPs）在土壤中的解吸/吸附会影响其迁移性和有效性。然而，由于缺乏适当的测量手段，这些过程的动力学尚未得到很好的研究。薄膜扩散梯度（DGT）技术可以评估土壤中的动力学过程，最近已被开发用于测量三种 BPs（BPA、BPB 和 BPF）。DGT 在具有不同土壤性质的五种土壤中部署了 2.5 小时至 20 天。DGT 随时间的质量积累呈非线性增加，表明 BPs 从土壤固相到溶液相的再供应较差。通过将数据与 DIFS（DGT 诱导的土壤通量）模型拟合，获得了 BPs 在土壤固相和溶液相之间的易变分配系数（K）、响应时间（t）和交换速率（k 和 k）的值。得出的 K 值表明，土壤中的大多数 BPs 都可以参与易变交换。平均响应时间为 1-2 小时，这意味着 DGT 对 BPs 的供应受到其解吸速率的限制。具有更多结合位点（更高的 DOM、CEC 和氧化铁）的土壤可以更快地再供应 BPs，突出了仅考虑分配效应的危险。
