Ammonium sulfide-assisted hydrothermal activation of palygorskite for enhanced adsorption of methyl violet

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• 作者：Guangyan Tian¹ ; ² ; ^{tianguangyan@licp.cas.cn" class="auth_mail" title="E-mail the corresponding author} ; Wenbo Wang¹ ; ³ ; Yuru Kang¹ ; ³ ; Aiqin Wang¹ ; ³ ; ^{aqwang@licp.cas.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Palygorskite ; Hydrothermal ; Adsorption ; Methyl violet
• 刊名：Journal of Environmental Sciences
• 出版年：2016
• 出版时间：March 2016
• 年：2016
• 卷：41
• 期：Complete
• 页码：33-43
• 全文大小：1196 K

文摘

Herein, palygorskite (PAL) was activated via a simple hydrothermal process in the presence of ammonium sulfide, and the effects of activation on the microstructure, physico-chemical feature and adsorption behaviors of PAL were intensively investigated. The hydrothermal process evidently improved the dispersion of PAL crystal bundles, increased surface negative charges and built more active –Si–O⁻ groups served as the new “adsorption sites”. The adsorption property of the activated PAL for Methyl Violet (MV) was systematically investigated by optimizing the adsorption variables, including pH, ionic strength, contact time and initial MV concentration. The activated PAL exhibited a superior adsorption capability to the raw PAL for the removal of MV (from 156.05 to 218.11 mg/g). The kinetics for MV adsorption followed pseudo second-order kinetic models, while the isotherm and thermodynamics results showed that the adsorption pattern well followed the Langmuir model. The structure analysis of PAL before and after adsorption demonstrated that electrostatic interaction and chemical association of –X–O⁻ are the prominent driving forces for the adsorption process.