3 research outputs found

    Cotton Fabric Functionalized with a β‑Cyclodextrin Polymer Captures Organic Pollutants from Contaminated Air and Water

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    Cotton fabric is covalently functionalized with a porous β-cyclodextrin polymer by including the fabric in the polymerization mixture. The resulting functionalized fabric (CD-TFP@cotton) sequesters organic micropollutants, such as bisphenol A, from water with outstanding speed and a capacity 10-fold higher than that of untreated cotton. The functionalized fabric also readily captures volatile organic compounds (VOCs) from the vapor phase more quickly and with a capacity higher than that of untreated cotton as well as three commercially available fabric-based adsorbents. Volatile adsorbed pollutants were fully extracted from CD-TFP@cotton under reduced pressure at room temperature, permitting simple reuse. These properties make cotton functionalized with the cyclodextrin polymer of interest for water purification membranes, odor controlling fabrics, and respirators that control exposure to VOCs. This functionalization approach is scalable, likely to be amenable to other fibrous substrates, and compatible with existing fiber manufacturing techniques

    β‑Cyclodextrin Polymer Network Sequesters Perfluorooctanoic Acid at Environmentally Relevant Concentrations

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    Per- and poly fluorinated alkyl substances (PFASs), notably perfluorooctanoic acid (PFOA), contaminate many ground and surface waters and are environmentally persistent. The performance limitations of existing remediation methods motivate efforts to develop effective adsorbents. Here we report a β-cyclodextrin (β-CD)-based polymer network with higher affinity for PFOA compared to powdered activated carbon, along with comparable capacity and kinetics. The β-CD polymer reduces PFOA concentrations from 1 μg L<sup>–1</sup> to <10 ng L<sup>–1</sup>, at least 7 times lower than the 2016 U.S. EPA advisory level (70 ng L<sup>–1</sup>), and was regenerated and reused multiple times by washing with MeOH. The performance of the polymer is unaffected by humic acid, a component of natural organic matter that fouls activated carbons. These results are promising for treating PFOA-contaminated water and demonstrate the versatility of β-CD-based adsorbents

    Benchmarking Micropollutant Removal by Activated Carbon and Porous β‑Cyclodextrin Polymers under Environmentally Relevant Scenarios

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    The cost-effective and energy-efficient removal of organic micropollutants (MPs) from water and wastewater is challenging. The objective of this research was to evaluate the performance of porous β-cyclodextrin polymers (P-CDP) as adsorbents of MPs in aquatic matrixes. Adsorption kinetics and MP removal were measured in batch and flow-through experiments for a mixture of 83 MPs at environmentally relevant concentrations (1 μg L<sup>–1</sup>) and across gradients of pH, ionic strength, and natural organic matter (NOM) concentrations. Performance was benchmarked against a coconut-shell activated carbon (CCAC). Data reveal pseudo-second-order rate constants for most MPs ranging between 1.5 and 40 g mg<sup>–1</sup> min<sup>–1</sup> for CCAC and 30 and 40000 g mg<sup>–1</sup> min<sup>–1</sup> for P-CDP. The extent of MP removal demonstrates slower but more uniform uptake on CCAC and faster but more selective uptake on P-CDP. Increasing ionic strength and the presence of NOM had a negative effect on the adsorption of MPs to CCAC but had almost no effect on adsorption of MPs to P-CDP. P-CDP performed particularly well for positively charged MPs and neutral or negatively charged MPs with McGowan volumes greater than 1.7 (cm<sup>3</sup> mol<sup>–1</sup>)/100. These data highlight advantages of P-CDP adsorbents relevant to MP removal during water and wastewater treatment
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