Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States.
Department of Civil and Environmental Engineering, Northwestern University, Evanston, Illinois 60208, United States.
Environ Sci Technol. 2023 Dec 5;57(48):19624-19636. doi: 10.1021/acs.est.3c04233. Epub 2023 Nov 7.
Trace organic contaminants (TrOCs) present major removal challenges for wastewater treatment. TrOCs, such as perfluoroalkyl and polyfluoroalkyl substances (PFAS), are associated with chronic toxicity at ng L exposure levels and should be removed from wastewater to enable safe reuse and release of treated effluents. Established adsorbents, such as granular activated carbon (GAC), exhibit variable TrOC removal and fouling by wastewater constituents. These shortcomings motivate the development of selective novel adsorbents that also maintain robust performance in wastewater. Cross-linked β-cyclodextrin (β-CD) polymers are promising adsorbents with demonstrated TrOC removal efficacy. Here, we report a simplified and potentially scalable synthesis of a porous polymer composed of styrene-linked β-CD and cationic ammonium groups. Batch adsorption experiments demonstrate that the polymer is a selective adsorbent exhibiting complete removal for six out of 13 contaminants with less adsorption inhibition than GAC in wastewater. The polymer also exhibits faster adsorption kinetics than GAC and ion exchange (IX) resin, higher adsorption affinity for PFAS than GAC, and is regenerable by solvent wash. Rapid small-scale column tests show that the polymer exhibits later breakthrough times compared to GAC and IX resin. These results demonstrate the potential for β-CD polymers to remediate TrOCs from complex water matrices.
痕量有机污染物 (TrOCs) 对废水处理构成了重大的去除挑战。TrOCs，如全氟烷基和多氟烷基物质 (PFAS)，在 ng L 暴露水平下与慢性毒性有关，因此应从废水中去除，以实现处理后废水的安全再利用和释放。已有的吸附剂，如颗粒活性炭 (GAC)，对 TrOC 的去除效果和受废水成分的污染情况存在差异。这些缺点促使人们开发具有选择性的新型吸附剂，这些吸附剂在废水中也能保持稳健的性能。交联 β-环糊精 (β-CD) 聚合物是一种很有前途的吸附剂，具有已证明的 TrOC 去除效果。在这里，我们报告了一种简化的、潜在可扩展的合成方法，用于合成一种由苯乙烯连接的 β-CD 和阳离子铵基团组成的多孔聚合物。批量吸附实验表明，该聚合物是一种选择性吸附剂，对 13 种污染物中的 6 种具有完全去除效果，在废水中的吸附抑制作用小于 GAC。该聚合物还表现出比 GAC 和离子交换 (IX) 树脂更快的吸附动力学，对 PFAS 的吸附亲和力高于 GAC，并且可以通过溶剂洗脱再生。快速小型柱试验表明，与 GAC 和 IX 树脂相比，该聚合物的穿透时间更晚。这些结果表明，β-CD 聚合物具有从复杂水基质中去除 TrOCs 的潜力。
