Adsorption of arsenite and arsenate onto muscovite and biotite mica

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• 作者：Sudipta Chakraborty ; Mariette Wolthers ; Debashis Chatterjee ; Laurent Charlet
• 关键词：Arsenic ; Phyllosilicate ; Adsorption ; Isotherm ; Edge ; Reactivity ; Release
• 刊名：Journal of Colloid and Interface Science
• 出版年：2007
• 出版时间：15 May 2007
• 年：2007
• 卷：309
• 期：2
• 页码：392-401
• 全文大小：486 K

文摘

Arsenite and arsenate sorption was studied on two silt-sized phyllosilicates, namely muscovite and biotite, as a function of solution pH (pH 3–8 for muscovite, and 3–11 for biotite) at an initial As concentration of 13 μM. The amount of arsenic adsorbed increases with increasing pH, exhibiting a maximum value, before decreasing at higher pH values. Maxima correspond to As(V) at pH 4.6–5.6 and As(III) at pH 4.1–6.2 for biotite, and As(III) and As(V) at pH 4.2–5.5 for muscovite. The constant capacitance surface complexation model was used to explain the adsorption behavior. Biotite provides greater reactivity than muscovite toward arsenic adsorption. Isotherm data obeyed the Freundlich or Langmuir equation for the arsenic concentration range 10⁻⁷–10⁻⁴ M. Released total Fe, Si, K, Al, and Mg in solution were analyzed. Calculation of saturation indices by PHREEQC indicated that the solution was undersaturated with respect to aluminum arsenate (AlAsO₄2H₂O), scorodite (FeAsO₄2H₂O), and claudetite/arsenolite (As₄O₆).