Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA.
Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA.
Water Res. 2021 Jan 1;188:116534. doi: 10.1016/j.watres.2020.116534. Epub 2020 Oct 20.
Humans and animals are frequently exposed to PFAS (per- and polyfluoroalkyl substances) through drinking water and food; however, no therapeutic sorbent strategies have been developed to mitigate this problem. Montmorillonites amended with the common nutrients, carnitine and choline, were characterized for their ability to bind 4 representative PFAS (PFOA, PFOS, GenX, and PFBS). Adsorption/desorption isothermal analysis showed that PFOA, PFOS (and a mixture of the two) fit the Langmuir model with high binding capacity, affinity and enthalpy at conditions simulating the stomach. A low percentage of desorption occurred at conditions simulating the intestine. The results suggested that hydrophobic and electrostatic interactions, and hydrogen bonding were responsible for sequestering PFAS into clay interlayers. Molecular dynamics (MD) simulations suggested the key mode of interaction of PFAS was through fluorinated carbon chains, and confirmed that PFOA and PFOS had enhanced binding to amended clays compared to GenX and PFBS. The safety and efficacy of amended montmorillonite clays were confirmed in Hydra vulgaris, where a mixture of amended sorbents delivered the highest protection against a PFAS mixture. These important results suggest that the inclusion of edible, nutrient-amended clays with optimal affinity, capacity, and enthalpy can be used to decrease the bioavailability of PFAS from contaminated drinking water and diets.
人类和动物经常通过饮用水和食物接触到 PFAS（全氟和多氟烷基物质）；然而，尚未开发出治疗性吸附剂策略来缓解这一问题。用常见的营养物质肉毒碱和胆碱改性的蒙脱石被表征为其结合 4 种代表性 PFAS（PFOA、PFOS、GenX 和 PFBS）的能力。吸附/解吸等温线分析表明，PFOA、PFOS（和两者的混合物）在模拟胃的条件下符合朗缪尔模型，具有高结合容量、亲和力和焓。在模拟肠道的条件下，解吸的百分比很低。结果表明，疏水力和静电力以及氢键是将 PFAS 隔离到粘土夹层中的原因。分子动力学 (MD) 模拟表明，PFAS 的关键相互作用模式是通过氟化碳链，并且证实与 GenX 和 PFBS 相比，PFOA 和 PFOS 对改性粘土的结合增强。改性蒙脱石粘土的安全性和功效在水螅中得到了证实，其中改性吸附剂的混合物对 PFAS 混合物提供了最高的保护。这些重要结果表明，可以使用包含最佳亲和力、容量和焓的可食用营养改性粘土来降低受污染饮用水和饮食中 PFAS 的生物利用度。
