Adsorption-Desorption of Chromium(VI) on Bentonites of Gansu Pingliang
Adsorption and desorption properties of Cr(VI) on Bentonites(Bt) and acid modified Bentonites(M-BT) were studied. The influences of initial solution pH, additives of inorganic electrolytes, NaCl, Na2CO3 and Zn(NO3)2 on the desorption of Cr(VI) were investigated, and the adsorption-desorption mechanism was discussed in combination with the results of experiments. It was found that the adsorption ability of modified Bentonites is larger than natural Bentonites, but the speed of adsorption is less. The adsorption kinetics and isotherms of Cr(VI) on the Bt and modified Bentonites can be described by the pseudo-second order kinetic and Langmuir isotherm, respectively. The desorption investigation indicated that increasing pH and concentration of additives of inorganic electrolytes the adsorption amount decreased, and NaCl could obviously restrain the adsorption of Cr(VI) on the sorbent. This suggested the adsorption of Cr(VI) on the sorbent arose from the anion exchange in the interlayer space and the adsorption on the external surface, respectively. The desorption kinetics accord with Elovich equation primely and the process of adsorption or desorption isn’t completely reversible.
bentonites chromium(VI) adsorption desorption
WANG Yi ZHANG Ting FENG Huixia QIU Jianhui
College of Petrochemical Technology,Lanzhou University of Technology,Lanzhou 730050,Gansu,China Department of Machine Intelligence and Systems Engineering Faculty of Systems Engineering,Akita Pref
国际会议
2009 International Symposium on Environmental Science and Technology(2009环境科学与技术国际会议)
上海
英文
1446-1451
2009-06-02（万方平台首次上网日期，不代表论文的发表时间）