State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, China E-mail:
Water Sci Technol. 2014;69(7):1489-95. doi: 10.2166/wst.2014.049.
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.
全氟辛烷磺酸 (PFOS) 是一种引起全球关注的持久性有机污染物。由于其独特的性质，碳纳米管 (CNTs) 引起了广泛的研究关注。本研究旨在探讨 PFOS 与 CNTs 的吸附行为，并阐明它们的相互作用。静电排斥抑制了 PFOS 对多壁碳纳米管 (MWCNTs) 的吸附，导致在高 pH 值下吸附性低。随着阴离子浓度的增加，PFOS 的去除率降低了 20%至 30%，因为离子强度改变了 MWCNTs 的聚集。与无机阴离子不同，包括 Cu(II) 和 Pb(II) 在内的阳离子金属对 MWCNTs 上 PFOS 的吸附有显著影响。在低浓度的 Cu(II) 和 Pb(II) 下，由于离子强度的抑制作用，PFOS 的去除率降低，而随着金属浓度的增加，PFOS 的去除率迅速增加，特别是对于功能化的 MWCNTs。在高浓度的 Cu(II) 和 Pb(II) 下，PFOS 的吸附增强归因于可能进一步吸附 PFOS 的吸附阳离子金属。
