Preparation and characterization of chitosan/montmorillonite magnetic microspheres and its application for the removal of Cr (VI)

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• 作者：Daimei Chen^a ; ^{chendaimei@cugb.edu.cn} ; Wa Li^a ; Yanru Wu^b ; Qian Zhu^a ; Zhijin Lu^a ; Gaoxiang Du^a
• 关键词：Chitosan ; Montmorillonite ; Magnetic microspheres ; Adsorption ; Cr (VI)
• 刊名：Chemical Engineering Journal
• 出版年：2013
• 出版时间：1 April, 2013
• 年：2013
• 卷：221
• 期：Complete
• 页码：8-15
• 全文大小：650 K

文摘

A magnetically separable adsorbent, named chitosan/montmorillonite-Fe₃O₄ (CTS/MMT-Fe₃O₄) microsphere is prepared by microemulsion process and characterized by infrared spectroscopic analysis (IR), X-ray Powder Diffraction (XRD) and scanning electron microscope (SEM). The microspheres are applied as adsorbents for the removal of Cr (VI) from aqueous solution. The effects of MMT content (wt % ), the initial concentration of Cr (VI) solution (C₀), initial pH value (pH₀) of Cr (VI) solution and the adsorption dose on the adsorption capacity of the microspheres are investigated. The adsorption experiments show that the adsorption capacity of CTS/xMMT-Fe₃O₄ microspheres for Cr (VI) is higher than the mean value of those of CTS and MMT. The optimum pH value for Cr (VI) adsorption is found at pH = 2, and the adsorption capacity increased with the increase in adsorption temperature. The adsorption kinetics is better described by the pseudo-second order equation, and their adsorption isotherms are better fitted to the Langmuir equation. Thermodynamic parameters such as ¦¤H^¡ã, ¦¤S^¡ã and ¦¤G^¡ã were calculated to understand the adsorption mechanism for Cr (VI). The adsorption-desorption experiments implied that CTS/MMT-Fe₃O₄ can be used as promising adsorbents for the removal of Cr (VI) from wastewater.