文章基本信息

标题：Kaolinite and Cd2 Transport and Interaction in Sand Media: Batch and Column Experiments
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作者：Rakkreat Wikiniyadhanee ; Srilert Chotpantarat ; Say Kee Ong 等
期刊名称：Terrestrial Atmospheric and Oceanic Sciences
印刷版ISSN：1017-0839
出版年度：2016
卷号：27
期号：2
页码：195-202
DOI：10.3319/TAO.2015.10.26.01(TT)
出版社：Chinese Geoscience Union
摘要：Batch sorption and column transport experiments were used to investigate kaolinite colloids and Cd(II) ions (Cd2 ) co-transport in water-saturated sand media. Batch sorption was used to evaluate Cd2 sorption onto kaolinite clay as a function of the initial Cd2 concentrations and solution ionic strengths as well as determining the equilibrium sorption isotherms. For very low ionic strength (&126;0 mM), the Langmuir isotherm was the more suitable isotherm for the experimental results while at higher ionic strength (&62; 0.45 mM) the Freundlich isotherm was the more suitable isotherm. The sorption parameters, KF, KL, n, and qm, were found to decrease with increasing ionic strength. For column transport experiments, Cd2 -bearing kaolinite colloids were found to be retained more in the column for an increase in the solution ionic strength. For example, the steady state breakthrough rate of Cd2 -bearing kaolinite colloids was 0.2 Ci/C0 for an ionic strength of 0.0 mM compared to about 0.05 Ci/C0 for ionic strengths of 0.45 and 0.9 mM. This increased Cd2 -bearing kaolinite colloid retention trend with increased solution ionic strength was likely due to the reduced zeta-potential and increased size of the colloid particles at higher ionic strengths. Consequently, the kaolinite-facilitated Cd2 concentration decreased with increasing solution ionic strength. In summary, solution ionic strength had a strong effect on the transport behavior of kaolinite-facilitated Cd2 and Cd2 -bearing kaolinite colloids through the sand column.
关键词：Cadmium; Colloids; Facilitated; Ionic strength; Kaolinite;