天然土壤中典型多溴联苯醚解吸过程的初步研究

选择5种有机质含量不同的天然土壤，采用批量实验方法考察典型多溴联苯醚8DE47的解吸行为，并尝试利用非线性Freundlich模型和线性模型模拟不同初试浓度条件下BDE47的土壤解吸过程。针对较为显著的器壁吸附影像，所有检测数据均进行器壁吸附定量修正。结果表明，BDE47土壤解吸过程总体分为初始的快解吸和后续的慢解吸两个阶段。在初始阶段，BDE47解吸过程表现为线性行为，但非线性特征随解吸时间延长呈现增强趋势。土壤有机质（用TOC表征）释放的溶解有机质是影响土壤中BDE47解吸行为差异的主要因素之一。

Preliminary Study on Desorption Procedures of Typical PBDE from Natural Soils

Polybrominated diphenyl ethers （PBDEs） are commonly used as the flame retardants in electronic industry and widely distributed in multi-media environments. In order to understand the transport and fate characteristics of BDE47, as a model compound, the desorption behaviors of BDE47 on 5 natural soil samples with different organic carbon contents were investigated by batch experiments with varied concentrations of BDE47 from 1 μg· kg^-1 to 10 μg· kg^-1 after a 30-d aging time, and the desorption isotherms were fitted by the nonlinear Freundlich equation and linear model, respectively. The kinetic procedure of desorption was studied using a soil sample pretreated at 5 μg· kg^-1 of BDE47. The experimental data were calibrated to subtract the influence of vessel wall sorption. The analytical results indicated that desorption kinetics of BDE47 from soil could be classified into an initial fast desorption and a subsequent slow desorption. The linear behavior was dominant at the initial stage; however, nonlinear characteristics gradually enhanced with the extension of desorption procedure. Dissolved organic matter released from soil organic carbon was one of the major factors influencing desorption properties of the soil samples.