Abstract:
The removal of per- and polyfluoroalkyl substances (PFAS) from drinking water is urgently needed. Here, we demonstrated high performance of vesicles on PFAS adsorption. Vesicles used in this study were enclosed amphiphile bilayers keeping their hydrophobic groups inside and their hydrophilic groups outside in water. The distribution coefficient Kd of perfluorooctane sulfonic acid (PFOS) for vesicles was 5.3 × 105 L/kg, which is higher than that for granulated activated carbon (GAC), and Kd of perfluorooctanoic acid (PFOA) for vesicles was 103-104 L/kg. The removal efficiencies of PFOA and PFOS adsorption on DMPC vesicles were 97.1 ± 0.1% and 99.4 ± 0.2%, respectively. The adsorption behaviors of PFOA and PFOS on vesicles were investigated by changing the number of cis-double bonds in the hydrophobic chains of the vesicle constituents. Moreover, vesicles formed by membranes in the different phases were also tested. The results revealed that, when vesicles are formed of a membrane in the liquid-crystalline (liquid-like) phase, the adsorption amounts of both PFOA and PFOS increased as the cis-double bond in the hydrocarbon chains decreased, which is considered due to molecular shape similarity. When vesicles are formed of a membrane in the gel (solid-like) phase, they do not adsorb PFAS as much as in the liquid-crystalline phase, even though the hydrocarbon chains do not have any cis-double bond. Our findings demonstrate that vesicles can be utilized as PFAS adsorbents by optimizing the structure of vesicle constituents and their thermodynamical phase. Indeed, the vesicles (DMPC) were demonstrated that they can adsorb PFOA and PFOS, and be coagulated by a coagulant even in environmental water. The coagulation will enable the removal of PFOA and PFOS from the water after adsorption.
摘要:
迫切需要从饮用水中去除全氟烷基物质和多氟烷基物质(PFAS)。这里,我们证明了囊泡对PFAS吸附的高性能。本研究中使用的囊泡是封闭的两亲性双层,将其疏水基团保持在水中,亲水基团保持在水中。全氟辛烷磺酸(PFOS)在囊泡中的分配系数Kd为5.3×105L/kg,高于颗粒状活性炭(GAC),用于囊泡的全氟辛酸(PFOA)的Kd为103-104L/kg。DMPC囊泡对PFOA和PFOS吸附的去除效率分别为97.1±0.1%和99.4±0.2%,分别。通过改变囊泡组分疏水链中顺式双键的数量,研究了PFOA和PFOS在囊泡上的吸附行为。此外,还测试了由不同相的膜形成的囊泡。结果显示,当囊泡由液晶(类液体)相的膜形成时,随着烃链中顺式双键的减少,PFOA和PFOS的吸附量都增加,这被认为是由于分子形状相似性。当囊泡由凝胶(固体状)相中的膜形成时,它们不像在液晶相中那样吸附PFAS,即使烃链没有任何顺式双键。我们的发现表明,通过优化囊泡成分的结构及其热力学相,囊泡可以用作PFAS吸附剂。的确,囊泡(DMPC)被证明可以吸附PFOA和PFOS,甚至在环境水中也被凝结剂凝结。该凝结将使得能够在吸附后从水中去除PFOA和PFOS。