Effect of solution chemistry on the adsorption of perfluorooctane sulfonate onto mineral surfaces.
Effect of solution chemistry on the adsorption of perfluorooctane sulfonate onto mineral surfaces.
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DOI：
10.1016/j.watres.2010.01.038
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发表时间：
2010-04
期刊：
影响因子：
12.8
通讯作者：
C. Tang;Q. Shiang Fu;Dawen Gao;C. Criddle;J. Leckie
中科院分区：
文献类型：
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作者：
C. Tang;Q. Shiang Fu;Dawen Gao;C. Criddle;J. Leckie
全氟辛烷磺酸（PFOS）是一种引起重大环境问题的新出现的污染物，但有关全氟辛烷磺酸在矿物表面吸附的资料非常有限。通过间歇吸附实验研究了不同溶液组成下针铁矿和二氧化硅对全氟辛烷磺酸的吸附。吸附到二氧化硅上的pH值，离子强度和钙浓度的影响很小，可能是由于非静电相互作用的主导地位。相反，在[H+]和[Ca 2 +]较高时，针铁矿对全氟辛烷磺酸的吸收显著增加，这可能是由于带负电荷的全氟辛烷磺酸分子与带正电荷的针铁矿表面之间的静电吸引力增强。在高离子强度下，pH的影响不太显著，可能是由于双电层压缩。在离子强度较高时，带强正电荷的针铁矿表面（pH 3）的全氟辛烷磺酸吸收量减少，而带弱电荷的针铁矿表面（pH 7和9）的全氟辛烷磺酸吸收量增加，这可能是由于全氟辛烷磺酸表面静电吸引力和全氟辛烷磺酸-全氟辛烷磺酸静电排斥力之间的竞争。还制定了一个概念模型，该模型涵盖全氟辛烷磺酸-表面和全氟辛烷磺酸-全氟辛烷磺酸的静电相互作用以及非静电相互作用，以了解溶液化学对全氟辛烷磺酸吸附到针铁矿和二氧化硅表面的影响。
Perfluorooctane sulfonate (PFOS) is an emergent contaminant of substantial environmental concerns, yet very limited information has been available on PFOS adsorption onto mineral surfaces. PFOS adsorption onto goethite and silica was investigated by batch adsorption experiments under various solution compositions. Adsorption onto silica was only marginally affected by pH, ionic strength, and calcium concentration, likely due to the dominance of non-electrostatic interactions. In contrast, PFOS uptake by goethite increased significantly at high [H+] and [Ca2+], which was likely due to enhanced electrostatic attraction between the negatively charged PFOS molecules and positively charged goethite surface. The effect of pH was less significant at high ionic strength, likely due to electrical double layer compression. PFOS uptake was reduced at higher ionic strength for a strongly positively charged goethite surface (pH 3), while it increased for a weakly charged surface (pH 7 and 9), which could be attributed to the competition between PFOS-surface electrostatic attraction and PFOS-PFOS electrostatic repulsion. A conceptual model that captures PFOS-surface and PFOS-PFOS electrostatic interactions as well as non-electrostatic interaction was also formulated to understand the effect of solution chemistry on PFOS adsorption onto goethite and silica surfaces.