Adsorption of perfluorooctane sulfonate on carbon nanotubes: influence of pH and competitive ions.
Adsorption of perfluorooctane sulfonate on carbon nanotubes: influence of pH and competitive ions.
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DOI：
10.2166/wst.2014.049
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发表时间：
2014-04
期刊：
影响因子：
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通讯作者：
Yue Bei;Shubo Deng;Ziwen Du;Bin Wang;Jun Huang;Gang Yu
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文献类型：
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作者：
Yue Bei;Shubo Deng;Ziwen Du;Bin Wang;Jun Huang;Gang Yu
全氟辛烷磺酸（PFOS）是引起全球关注的持久性有机污染物之一。碳纳米管（Carbon nanotubes, CNTs）由于其独特的性能受到了广泛的关注。本研究旨在研究全氟辛烷磺酸与碳纳米管的吸附行为，并阐明它们之间的相互作用。静电斥力抑制了PFOS对多壁碳纳米管（MWCNTs）的吸附，导致在高ph下吸附量低。随着阴离子浓度的增加，由于离子强度改变了MWCNTs的聚集，PFOS的去除率降低了20% ~ 30%。与无机阴离子不同，包括Cu（II）和Pb（II）在内的阳离子金属对PFOS在MWCNTs上的吸附有显著影响。在低浓度Cu（II）和Pb（II）时，由于离子强度的抑制作用，PFOS去除率降低，而随着金属浓度的增加，PFOS去除率迅速增加，特别是对于功能化的MWCNTs。高Cu（II）和Pb（II）浓度对PFOS的吸附增强是由于吸附的阳离子金属可能进一步吸附PFOS。
Perfluorooctane sulfonate (PFOS) is one of the persistent organic pollutants that has aroused global concern. Carbon nanotubes (CNTs) have drawn much research attention due to their unique properties. This study was aimed to investigate the adsorption behaviour of PFOS with relation to CNTs and clarify their interactions. Electrostatic repulsion suppressed the sorption of PFOS to multi-walled carbon nanotubes (MWCNTs), resulting in low sorption at high pH. With the increase of anion concentration, the removal of PFOS decreased by 20 to 30% because ionic strength changed the aggregation of the MWCNTs. Unlike inorganic anions, cationic metals including Cu(II) and Pb(II) had a significant impact on the sorption of PFOS onto the MWCNTs. At low concentrations of Cu(II) and Pb(II), PFOS removal decreased due to the suppressive effect of ionic strength, while the removal of PFOS increased rapidly with increasing metal concentrations, especially for functionalized MWCNTs. The enhanced adsorption of PFOS at high Cu(II) and Pb(II) concentrations was attributed to the adsorbed cationic metals which might further adsorb PFOS.