基于表面活性剂强化萃取的强疏水性有机污染物LDPE膜/水分配系数研究

Reaching an equilibrium in low density polyethylene (LDPE)–water phase takes a long time for very hydrophobic organic contaminants (VHOCs). This becomes the bottleneck which restricts the further application of the passive sampling technique. The indirect medium is able to provide an feasible approach for solving this problem. Using surfactant (Brij30) as an indirect medium, the study on the enhanced extraction process of high concentration and high toxicity VHOCs by surfactant was carried out. The main research aims to: (i) investigate the solubilization of VHOCs by surfactant and determine the partition coefficients in micellar solutions (Kmic-w); (ii) investigate the trend of accmulation in the micellar phase and LDPE; the changing of extraction process; determination of the partition coefficients of VHOCs in LDPE film and the micellar phase (KPE-mic); (iii) examine the correlations among KPE-w / octanol-water partition coefficient (Kow), molecular weight, molecular structure and activity coefficients; establish an indirect method based model for determining the equilibrium partition coefficients of VHOCs in LDPE and water phase(KPE-w) and validate the model by use of experimental data; Explain extraction process and its mechanism from the micro scale. This study is expected to provide theoretical accordance and technology support for application and development of low density polyethylene film as an effective passive sampling technique.

强疏水性有机污染物在低密度聚乙烯膜/水中达到分配平衡耗时长，成为制约该被动采样技术进一步推广的瓶颈，而间接法介质的引入为这一难点的突破提供了有效途径。本项目以环境中浓度高、毒性强的强疏水性有机污染物为研究对象，利用十二烷基聚氧乙烯醚为间接法介质，系统研究表面活性剂强化有机污染物萃取平衡过程。具体内容包括：研究表面活性剂对强疏水性有机污染物的助溶特性，测算目标物在胶束溶液中达到饱和时的分配系数；研究目标物在LDPE与胶束相中富集量的变化趋势及萃取过程，确定目标物在LDPE与胶束相中达到动态平衡时的分配系数；研究膜/水分配系数与辛醇/水分配系数、分子量、分子结构和活度系数的相关性，构建基于表面活性剂强化萃取的强疏水性有机污染物LDPE膜/水分配系数的测定模型，对其进行验证评价。从微观学的尺度上揭示萃取机理，为扩展低密度聚乙烯膜作为吸附相的被动采样技术的应用和发展提供理论依据和技术支持。

本项目以强疏水性有机污染物为研究对象，利用十二烷基聚氧乙烯醚为间接法介质，系统研究表面活性剂强化有机污染物萃取平衡过程。研究表面活性剂对强疏水性有机污染物的助溶特性，测算目标物在胶束溶液中达到饱和时的分配系数；研究目标物在LDPE与胶束相中富集量的变化趋势及萃取过程，确定目标物在LDPE与胶束相中达到动态平衡时的分配系数；研究膜/水分配系数与辛醇/水分配系数、分子结构与活性的相关性，构建基于表面活性剂强化萃取的强疏水性有机污染物LDPE膜/水分配系数的测定和预测模型，对其进行验证评价。为被动采样技术的应用和发展提供理论依据和技术支持。