Different transport behaviors and mechanisms of perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) in saturated porous media.
Different transport behaviors and mechanisms of perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) in saturated porous media.
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DOI：
10.1016/j.jhazmat.2020.123435
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发表时间：
2020-07
影响因子：
13.6
通讯作者：
Yingna Xing;Qi Li;Xin Chen;Xiaowen Fu;Lei Ji;Jia-ning Wang;Tianyuan Li;Qiang Zhang
中科院分区：
文献类型：
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作者：
Yingna Xing;Qi Li;Xin Chen;Xiaowen Fu;Lei Ji;Jia-ning Wang;Tianyuan Li;Qiang Zhang
全氟辛酸盐（PFOA）和全氟辛烷磺酸盐（PFOS）在土壤中的污染问题日益引起人们的关注，但其在多孔介质中的迁移规律研究较少，因此迫切需要对其进行研究以更好地控制其环境风险。采用饱和砂柱（考虑溶液阳离子类型和pH的耦合效应）和双点非平衡迁移模型（TSM）研究了PFOA和PFOS在土壤中的迁移行为和机制。穿透数据和TSM参数表明，PFOA比PFOS具有更高的迁移率，二价阳离子可以通过增加它们与沙子之间的非平衡相互作用来抑制它们的迁移。由于PFOA与沙粒的亲合力有限，当溶液中只有一价阳离子时，pH对PFOA迁移的影响不大，而多价阳离子通过阳离子桥连为其提供了额外的吸附位点，增强了pH的作用。这证明了对溶液pH值敏感的氢键等机制在全氟辛烷磺酸迁移中发挥了重要作用。研究结果为PFOA和PFOS的修复策略和迁移预测模型的建立提供了重要的科学依据。
Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) in soil aroused increasing concern, however there is little information about their transport in porous media, which is urgently needed to better control their environmental risks. In this study, saturated sand columns (considering the coupled effect of solution cation type and pH) and a two-site nonequilibrium transport model (TSM) were used to investigate the transport behaviors and mechanisms of PFOA and PFOS. Breakthrough data and the TSM parameters showed PFOA had higher mobility than PFOS, and divalent cation could inhibit their transport by increasing the nonequilibrium interactions between them and the sand. pH had little influence on PFOA migration when there was only monovalent cation in the solution since PFOA had limited affinity with the sand, however, polyvalent cation could provide additional adsorption sites for it through cation bridging and enhance the effect of pH. Differently, decreasing pH inhibited the transport of PFOS more significantly, and the effect was stronger than that of changing cation type. That proved mechanisms like hydrogen-bonding which were sensitive to solution pH played an important role in PFOS migration. These results provide important scientific basis to the remediation strategy and the migration prediction model development of PFOA and PFOS.