Removal of typical PFAS from water by covalent organic frameworks with different pore sizes.
Removal of typical PFAS from water by covalent organic frameworks with different pore sizes.
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DOI：
10.1016/j.jhazmat.2023.132522
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发表时间：
2023-09
影响因子：
13.6
通讯作者：
Wen Wang;Ye Jia;Shuangxi Zhou;Shubo Deng
中科院分区：
文献类型：
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作者：
Wen Wang;Ye Jia;Shuangxi Zhou;Shubo Deng
吸附对水中全氟烷基和多氟烷基物质（PFAS）的去除是非常有效和理想的，合适的多孔吸附剂孔径对PFAS的有效去除至关重要，但吸附剂孔径与PFAS吸附之间的关系尚不清楚。本研究成功合成了5种不同孔径的规则共价有机框架（COFs），并研究了COFs孔径与PFAS长度对PFAS高效吸附的相关性。COFs的孔径过小或过大，由于扩散阻碍和结合力较弱，都不利于PFAS的有效吸附。孔径为PFAS分子大小2.5 ~ 4.0倍的COFs对PFAS的吸附效果最佳。本研究还通过对吸附系统进行曝气和脱气处理，考察纳米气泡对PFAS在有序多孔COFs上吸附的潜在影响。疏水COFs上的气泡吸附了PFAS，这是PFAS在COFs上的另一个重要吸附机制。与短链PFAS相比，长链PFAS在气液界面处具有更强的富集，因此长链PFAS具有更高的吸附能力。
Adsorption is highly effective and desirable for the removal of per- and polyfluoroalkyl substances (PFAS) from water, and suitable pore size of porous adsorbents is important for efficient removal of PFAS, but the relationship between adsorbent pore size and PFAS adsorption remains unclear. In this study, five regular covalent organic frameworks (COFs) with distinct pore sizes were successfully synthesized, and the correlation between the pore size of COFs and PFAS length for efficient PFAS adsorption was investigated. Both excessively small and large pore sizes of COFs are not conducive to the efficient adsorption of PFAS due to the diffusion hindrance and weak binding forces. The COFs with a pore size ranging from 2.5 to 4.0 times of the PFAS molecular size demonstrated the most suitable for PFAS adsorption. This study also investigated the potential impact of nanobubbles on PFAS adsorption on orderly porous COFs through aeration and degassing treatment of the adsorption system. The bubbles on hydrophobic COFs were verified to be responsible for PFAS adsorption, another important adsorption mechanism of PFAS on COFs. The long-chain PFAS have stronger enrichment at the gas-liquid interface than the short-chain PFAS, resulting in higher adsorption capacity for long-chain PFAS.