Enhanced Sorption of Perfluorooctanoic Acid with Organically Functionalized Layered Double Hydroxide
Enhanced Sorption of Perfluorooctanoic Acid with Organically Functionalized Layered Double Hydroxide
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DOI：
10.1016/j.cej.2022.137019
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发表时间：
2022-05
影响因子：
15.1
通讯作者：
Xiaopeng Min;Jingwan Huo;Qianqian Dong;Shangping Xu;Yin Wang
中科院分区：
文献类型：
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作者：
Xiaopeng Min;Jingwan Huo;Qianqian Dong;Shangping Xu;Yin Wang
吸附被公认为是实际处理受全氟烷基和多氟烷基物质(PFAS)污染的水的一种有效和经济的方法。在这项研究中，我们报道了一系列新型有机功能化层状双氢氧化物(LDH)吸附剂的开发、表征和评价，主要集中在全氟辛酸(PFOA)。有机官能团通过接枝后共价键合的方式引入到锌铝水滑石中。有机功能化的LDHs对全氟辛酸的吸附非常有效，这可能是因为LDHs的带正电荷的结构层提供了强大的静电相互作用，而改性的有机官能团提供了增强的疏水相互作用来捕获全氟辛酸。具体来说，我们的吸附动力学和吸附等温线研究发现，有机官能化的LDH比未修饰的LDH表现出更快的吸附动力学和更大的对PFOA的吸附容量。此外，在不同的水化学条件下，有机功能化的LDH对全氟辛酸的去除表现出比未改性的LDH显著提高的性能，并且在反复吸附-再生循环后仍然更有效。性能最好的有机官能化LDH对具有不同氟烷基链长度和官能度的PFAS混合物也显示出高效率。这项工作的结果表明，有机功能化的LDHs在处理全氟辛烷磺酸污染的水方面有很大的前景。
Sorption is recognized as an effective and economical approach for the practical treatment of water contaminated with per- and polyfluoroalkyl substances (PFAS). In this study, we reported the development, characterization, and evaluation of a family of new organically functionalized layered double hydroxide (LDH) adsorbents for PFAS removal with a primary focus on perfluorooctanoic acid (PFOA). The organic functional groups were introduced to the Zn-Al LDH by covalent bonding through a post-grafting process. The organically functionalized LDHs were very efficient for PFOA adsorption, likely due to the synergy of the positively charged structural layers of LDHs that provide strong electrostatic interactions and the modified organic functional groups that provide enhanced hydrophobic interactions to capture PFOA. Specifically, our adsorption kinetics and isotherm studies found that organically functionalized LDHs exhibited faster adsorption kinetics and greater adsorption capacities for PFOA than the unmodified LDH. Furthermore, organically functionalized LDHs showed substantially improved performance for PFOA removal under various water chemistry conditions in comparison to the unmodified LDH, and remained more effective following repeated adsorption-regeneration cycles. The best-performed organically functionalized LDH also exhibited high efficiency for the treatment of a mixture of PFAS with varied fluoroalkyl chain lengths and functionalities. Results of this work suggested that organically functionalized LDHs hold great promises for the treatment of PFAS-contaminated water.