Comparative sorption and desorption behaviors of PFHx S and PFOS on sequentially extracted humic substances  

作　　者：Lixia Zhao Yifeng Zhang Shuhong Fang Lingyan Zhu Zhengtao Liu 

机构地区：[1]Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University [2]Chinese Research Academy of Environmental Sciences

出　　处：《Journal of Environmental Sciences》2014年第12期2517-2525,共9页环境科学学报（英文版）

基　　金：support of Chinese Natural Science Foundation(No.21277077,21325730);Ministry of Education(No.20130031130005);Ministry of Science and Technology(No.2012ZX07529-003);Ministry of Education Innovation Team(IRT 13024)

摘　　要：The sorption and desorption behaviors of two perfluoroalkane sulfonates（PFSAs）, including perfluorohexane sulfonate（PFHx S） and perfluorooctane sulfonate（PFOS） on two humic acids（HAs） and humin（HM）, which were extracted from a peat soil, were investigated. The sorption kinetics and isotherms showed that the sorption of PFOS on the humic substances（HSs） was much higher than PFHx S. For the same PFSA compound, the sorption on HSs followed the order of HM 〉 HA2 〉 HA1. These suggest that hydrophobic interaction plays a key role in the sorption of PFSAs on HSs. The sorption capacities of PFSAs on HSs were significantly related to their aliphaticity, but negatively correlated to aromatic carbons,indicating the importance of aliphatic groups in the sorption of PFSAs. Compared to PFOS,PFHx S displayed distinct desorption hysteresis, probably due to irreversible pore deformation after sorption of PFHx S. The sorption of the two PFSAs on HSs decreased with an increase in p H in the solution. This is ascribed to the electrostatic interaction and hydrogen bonding at lower p H. Hydrophobic interaction might also be stronger at lower p H due to the aggregation of HSs.The sorption and desorption behaviors of two perfluoroalkane sulfonates（PFSAs）, including perfluorohexane sulfonate（PFHx S） and perfluorooctane sulfonate（PFOS） on two humic acids（HAs） and humin（HM）, which were extracted from a peat soil, were investigated. The sorption kinetics and isotherms showed that the sorption of PFOS on the humic substances（HSs） was much higher than PFHx S. For the same PFSA compound, the sorption on HSs followed the order of HM 〉 HA2 〉 HA1. These suggest that hydrophobic interaction plays a key role in the sorption of PFSAs on HSs. The sorption capacities of PFSAs on HSs were significantly related to their aliphaticity, but negatively correlated to aromatic carbons,indicating the importance of aliphatic groups in the sorption of PFSAs. Compared to PFOS,PFHx S displayed distinct desorption hysteresis, probably due to irreversible pore deformation after sorption of PFHx S. The sorption of the two PFSAs on HSs decreased with an increase in p H in the solution. This is ascribed to the electrostatic interaction and hydrogen bonding at lower p H. Hydrophobic interaction might also be stronger at lower p H due to the aggregation of HSs.

关 键 词：Perfluorohexane sulfonate（PFHx S） Perfluorooctane sulfonate（PFOS） Humic substances（HSs） SORPTION DESORPTION 

分 类 号：X131[环境科学与工程—环境科学]