Efficient removal of perfluorinated compounds from water using a regenerable magnetic activated carbon
Efficient removal of perfluorinated compounds from water using a regenerable magnetic activated carbon
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使用可再生磁性活性炭有效去除水中的全氟化化合物
DOI：
10.1016/j.chemosphere.2019.02.132
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发表时间：
2019
期刊：
影响因子：
8.8
通讯作者：
Deng Shubo
中科院分区：
文献类型：
--
作者：
Meng Pingping;Fang Xiaolu;Maimaiti Ayiguli;Yu Gang;Deng Shubo
粉末活性碳(PAC)吸附是目前公认的去除水中全氟化合物(PFC)的有效方法，但废PAC分离能力差，难以进一步再生，大大增加了处理成本。本研究采用球磨法制备了Fe3O4和PAC组成的超细磁性活性碳(MAC)，以有效去除水中的PFC。随着Fe3O4含量的增加和球磨时间的延长，其对全氟辛烷磺酸(PFOS)的吸附容量降低，但磁选性能有所提高。当Fe3O4与PAC的质量比为1：3，球磨2 h后，4种PFC在2 h内均达到吸附平衡，对全氟辛酸、全氟辛酸、全氟己烷磺酸和全氟丁烷磺酸的吸附容量分别为1.6 3、0.90、0.33和0.2 1 /g。当溶液pH小于MAC的零电位点(约6)时，由于静电引力的降低，溶液pH的升高对全氟辛烷磺酸的吸附有明显的阻碍作用。废旧MAC易于磁体分离和少量甲醇再生，再生后的MAC可重复使用5次以上，循环3次后仍保持对全氟辛烷磺酸的稳定吸附能力。本研究为可分离磁性PAC去除废水中的全氟碳化物提供了有益的启示。
Adsorption by powder activated carbon (PAC) is recognized as an efficient method for the removal of perfluorinated compounds (PFCs) in water, while the poor separation of spent PAC makes it difficult for further regeneration, increasing the treatment cost significantly. In this study, an ultrafine magnetic activated carbon (MAC) consisting of Fe3O4and PAC was prepared by ball milling to remove PFCs from water efficiently. Increasing the percentage of Fe3O4and balling milling time decreased its adsorption capacity for perfluoroctane sulfonate (PFOS), whereas increased the magnetic separation property to some degree. The optimized MAC was prepared with a Fe3O4to PAC mass ratio of 1:3 after ball milling for 2 h, and the adsorption equilibriums of all the four PFCs on the optimal MAC were reached within less than 2 h, with the adsorption capacities of 1.63, 0.90, 0.33 and 0.21 mmol/g for PFOS, perfluorooctanoic acid (PFOA), perfluorohexane sulfonate (PFHxS) and perfluorobutane sulfonate (PFBS), respectively. Increasing the solution pH hindered the adsorption of PFOS significantly when the pH was less than the zero potential point (around 6) of the MAC, due to the decreased electrostatic attraction. The spent MAC could be easily separated with a magnet and regenerated by a small volume of methanol, and the regenerated MAC could be reused for more than 5 time and remain stable adsorption capacity for PFOS after 3 cycles. This study provides useful insights into the removal of PFCs by separable magnetic PAC in wastewater.