Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology , Linggong Road 2, Dalian 116024, People's Republic of China.
Environ Sci Technol. 2011 Oct 1;45(19):8498-505. doi: 10.1021/es202026v. Epub 2011 Sep 8.
Removal of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) from aqueous solution has attracted wide attention in light of their environmental persistence, bioaccumulation, and potential toxicity. Although various destructive technologies were developed, removal of PFOX (X = A and S) under mild conditions are still desirable. In this work, multiwalled carbon nanotubes (MWNTs) were applied to remove PFOX in electrochemically assistant adsorption. Electrosorption kinetics and isotherms were investigated relative to open circuit (OC) adsorption and adsorption on powder MWNTs. Compared with powder MWNTs adsorption, the initial adsorption rate (υ(0)) of 100 μg/L PFOX at 0.6 V increased 60-fold (PFOA) and 41-fold (PFOS) according to pseudosecond-order kinetics model and the maximum electrosorption capacity (q(m)) of PFOX (50 μg/L to 10 mg/L) increased 150-fold (PFOA) and 94-fold (PFOS) simulated with Langmuir model. These significant improvements were assumed to benefit from enhanced electrostatic attraction under electrochemical assistance. Furthermore, the used MWNTs were found to be regenerative and reusable. This work provides not only a new approach to effective removal of perfluorochemicals from aqueous solution but also a low energy-consumption and environmentally-friendly strategy for application of carbon nanotubes in water treatment.
由于全氟辛酸（PFOA）和全氟辛烷磺酸（PFOS）在环境中的持久性、生物累积性和潜在毒性，从水溶液中去除它们引起了广泛关注。尽管已经开发了各种破坏性技术，但仍需要在温和条件下去除 PFOX（X = A 和 S）。在这项工作中，多壁碳纳米管（MWNTs）被应用于电化学辅助吸附中去除 PFOX。相对于开路（OC）吸附和粉末 MWNTs 吸附，研究了电吸附动力学和等温线。与粉末 MWNTs 吸附相比，根据拟二级动力学模型，在 0.6 V 时，初始吸附速率（υ(0)）从 100 μg/L PFOX 增加了 60 倍（PFOA）和 41 倍（PFOS），最大电吸附容量（q(m)）从 50 μg/L 到 10 mg/L 的 PFOX 增加了 150 倍（PFOA）和 94 倍（PFOS），这是根据 Langmuir 模型模拟的。这些显著的改进被认为得益于电化学辅助下增强的静电吸引力。此外，所使用的 MWNTs 被发现是可再生和可重复使用的。这项工作不仅为从水溶液中有效去除全氟化学品提供了一种新方法，而且为在水处理中应用碳纳米管提供了一种低能耗和环保的策略。
