Sharlin Samiha, Lozano Rodrigo A, Josephson Tyler R
Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250, United States.
Department of Chemistry, University of California Irvine, 1120 E Peltason Dr, Irvine, California 92617, United States.
J Chem Theory Comput. 2024 Jul 23;20(14):5854-5865. doi: 10.1021/acs.jctc.4c00236. Epub 2024 Jul 10.
1,4-dioxane, an emerging water pollutant with high production volumes, is a probable human carcinogen. The inadequacy of conventional treatment processes demonstrates the need for an effective remediation strategy. Crystalline nanoporous materials are cost-effective adsorbents due to their high capacity and selective separation in mixtures. This study explores the potential of all-silica zeolites for the separation of 1,4-dioxane from water. These zeolites are highly hydrophobic and can preferentially adsorb nonpolar molecules from mixtures. We investigated six zeolite frameworks (BEA, EUO, FER, IFR, MFI, and MOR) using Monte Carlo simulations in the Gibbs ensemble. The simulations indicate high selectivity by FER and EUO, especially at low pressures, which we attribute to pore sizes and shapes with a greater affinity to 1,4-dioxane. We also demonstrate a Monte Carlo simulation workflow using gauge cells to model the adsorption of an aqueous solution of 1,4-dioxane at a 0.35 ppb concentration. We quantify 1,4-dioxane and water coadsorption and observe selectivities ranging from 1.1 × 10 in MOR to 8.7 × 10 in FER. We also demonstrate that 1,4-dioxane is in the infinite dilution regime in the aqueous phase at this concentration. This simulation technique can be extended to model other emerging water contaminants such as perfluoroalkyl and polyfluoroalkyl substances (PFAS), chlorofluorocarbons, and others, which are also found in extremely low concentrations.
1,4 - 二氧六环是一种产量高且新出现的水体污染物，它很可能是一种人类致癌物。传统处理工艺的不足表明需要一种有效的修复策略。结晶纳米多孔材料因其高吸附容量和对混合物的选择性分离能力而成为具有成本效益的吸附剂。本研究探索了全硅沸石从水中分离1,4 - 二氧六环的潜力。这些沸石具有高度疏水性，能够优先从混合物中吸附非极性分子。我们在吉布斯系综中使用蒙特卡罗模拟研究了六种沸石骨架（BEA、EUO、FER、IFR、MFI和MOR）。模拟结果表明FER和EUO具有高选择性，尤其是在低压下，我们将其归因于对1,4 - 二氧六环具有更大亲和力的孔径和形状。我们还展示了一种使用规范单元的蒙特卡罗模拟工作流程，以模拟浓度为0.35 ppb的1,4 - 二氧六环水溶液的吸附情况。我们对1,4 - 二氧六环和水的共吸附进行了量化，观察到选择性范围从MOR中的1.1×10到FER中的8.7×10。我们还证明了在此浓度下1,4 - 二氧六环在水相中处于无限稀释状态。这种模拟技术可以扩展到模拟其他新出现的水体污染物，如全氟烷基和多氟烷基物质（PFAS）、氯氟烃等，这些物质也以极低浓度存在。
