Key Lab of Eco-Restoration of Regional Contaminated Environment (Shenyang University), Ministry of Education, Shenyang 11044, China.
Qinghai 906 Engineering Survey and Design Institute Co. LTD, Xining 810001, China; Bureau of Qinghai Environmental Geological Prospecting, Xining 810001, China.
J Contam Hydrol. 2024 Jul;265:104387. doi: 10.1016/j.jconhyd.2024.104387. Epub 2024 Jun 15.
Steroid estrogens have posed significant ecological risks to aquatic organisms due to their potent endocrine-disrupting effects. The role of natural mineral colloids in facilitating the transport of hydrophobic organic pollutants in the environment has been confirmed, but the control mechanisms of colloids on 17α-Ethinylestradiol (EE2) migration in the subsurface environment are often still not well understood. This study combined the batch sorption equilibrium experiments and dynamic transport simulations to reveal the interface interactions and co-transport characteristics between illite colloids and EE2 at both macroscopic and microscopic levels. The existing form changes of EE2 and the influence of coexisting humic acid (HA) during transport in porous media were also specifically investigated. The batch experiments demonstrated that the primary mechanisms governing EE2 sorption onto illite colloids involved surface sorption and hydrogen bonding. The coexistence of HA could load onto the surface of illite colloids, thereby enhancing the colloidal sorption capacity for EE2. Transport experiments demonstrated that the migratory ability of EE2 in silty clay was limited, but illite colloids could significantly promote its penetration, with the peak penetration content (CC) increasing from 0.64 to 0.77. In the absence of HA, EE2 primarily transported in a dissolved form, accounting for 62.86% of the total concentrations. When HA concentrations were increased to 10 mg/L and 20 mg/L, the proportion of colloidal conjugate EE2 in the effluents reached 52.13% and 54.49%, respectively. The enhanced transport of EE2 by HA was primarily attributed to the improved migration ability of illite colloids and the increased proportion of illite-EE2 conjugate, resulting in a maximum CC value of 0.94. The validity of these results was further confirmed by employing calculations based on the Derjaguin-Landau-Verwey-Overbeek and Colloidal Filtration Theory. This study provides new insights of understanding the transport of EE2 in subsurface environment.
甾体雌激素由于其强大的内分泌干扰作用，对水生生物构成了重大的生态风险。天然矿物胶体在促进环境中疏水性有机污染物的迁移方面的作用已得到证实，但胶体对地下环境中 17α-乙炔基雌二醇（EE2）迁移的控制机制通常仍不为人所理解。本研究结合批量吸附平衡实验和动态传输模拟，从宏观和微观层面揭示了伊利石胶体与 EE2 之间的界面相互作用和共输特性。还特别研究了 EE2 在多孔介质中传输时的存在形态变化以及共存腐殖酸（HA）的影响。批实验表明，EE2 吸附到伊利石胶体上的主要机制包括表面吸附和氢键。HA 的共存可以加载到伊利石胶体的表面，从而增强胶体对 EE2 的吸附能力。传输实验表明，EE2 在粉质粘土中的迁移能力有限，但伊利石胶体可以显著促进其穿透，穿透含量峰值（CC）从 0.64 增加到 0.77。在不存在 HA 的情况下，EE2 主要以溶解形式运输，占总浓度的 62.86%。当 HA 浓度增加到 10 mg/L 和 20 mg/L 时，流出物中胶体共轭 EE2 的比例分别达到 52.13%和 54.49%。HA 增强 EE2 的传输主要归因于伊利石胶体迁移能力的提高和伊利石-EE2 轭合物比例的增加，导致最大 CC 值达到 0.94。基于德加古林-朗道-弗维-奥弗贝克和胶体过滤理论的计算进一步证实了这些结果的有效性。这项研究为理解地下环境中 EE2 的传输提供了新的见解。
