Key Laboratory of Marine Environmental Science and Ecology, Ministry of Education, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, P. R. China.
College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
Environ Sci Technol. 2021 Aug 3;55(15):10480-10490. doi: 10.1021/acs.est.1c01919. Epub 2021 Jul 21.
The transport and retention behavior of perfluorooctanoic acid (PFOA) in the presence of a hydrocarbon surfactant under saturated and unsaturated conditions was investigated. Miscible-displacement transport experiments were conducted at different PFOA and sodium dodecyl sulfate (SDS) input ratios to determine the impact of SDS on PFOA adsorption at solid-water and air-water interfaces. A numerical flow and transport model was employed to simulate the experiments. The PFOA breakthrough curves for unsaturated conditions exhibited greater retardation compared to those for saturated conditions in all cases, owing to air-water interfacial adsorption. The retardation factor for PFOA with a low concentration of SDS (PFOA-SDS ratio of 10:1) was similar to that for PFOA without SDS under unsaturated conditions. Conversely, retardation was greater in the presence of higher levels of SDS (1:1 and 1:10) with retardation factors increasing from 2.4 to 2.9 and 3.6 under unsaturated conditions due to enhanced adsorption at the solid-water and air-water interfaces. The low concentration of SDS had no measurable impact on PFOA air-water interfacial adsorption coefficients () determined from the transport experiments. The presence of SDS at the higher PFOA-SDS concentration ratios increased the surface activity of PFOA, with transport-determined values increased by 27 and 139%, respectively. The model provided very good independently predicted simulations of the measured breakthrough curves and showed that PFOA and SDS experienced various degrees of differential transport during the experiments. These results have implications for the characterization and modeling of poly-fluoroalkyl substances (PFAS) migration potential at sites wherein PFAS and hydrocarbon surfactants co-occur.
在饱和和不饱和条件下，研究了全氟辛酸（PFOA）在烃表面活性剂存在下的迁移和保留行为。进行了不同 PFOA 和十二烷基硫酸钠（SDS）输入比的可混相驱替传输实验，以确定 SDS 对固-水和气-水界面上 PFOA 吸附的影响。采用数值流动和传输模型模拟实验。在所有情况下，与饱和条件相比，不饱和条件下的 PFOA 突破曲线表现出更大的迟滞，这是由于气-水界面吸附所致。低浓度 SDS（PFOA-SDS 比为 10:1）下的 PFOA 迟滞因子与不饱和条件下无 SDS 时的 PFOA 相似。相反，在较高浓度 SDS（1:1 和 1:10）存在下，迟滞更大，由于固-水和气-水界面吸附增强，迟滞因子分别从 2.4 增加到 2.9 和 3.6。低浓度 SDS 对从传输实验确定的 PFOA 气-水界面吸附系数（）没有可测量的影响。在较高的 PFOA-SDS 浓度比下存在 SDS 会增加 PFOA 的表面活性，使由传输确定的值分别增加了 27%和 139%。该模型对测量的突破曲线进行了非常好的独立预测模拟，表明在实验过程中 PFOA 和 SDS 经历了不同程度的差异传输。这些结果对于在多氟烷基物质（PFAS）和烃表面活性剂共存的地点，对 PFAS 迁移潜力的表征和建模具有重要意义。
