Effect of environmental conditions on Pb(II) adsorption on β-MnO2
Effect of environmental conditions on Pb(II) adsorption on β-MnO2
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DOI：
10.1016/j.cej.2010.08.014
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发表时间：
2010-10-15
影响因子：
15.1
通讯作者：
Wang, Xiangke
中科院分区：
文献类型：
--
作者：
Zhao, Donglin;Yang, Xin;Wang, Xiangke
采用间歇吸附技术研究了不同环境条件(如接触时间、pH值、离子强度、腐植酸(HA)/黄腐酸(FA)和温度等)对β-MnO2吸附铅(II)的影响。结果表明，β-MnO2对Pb2+的吸附明显依赖于pH，而与离子强度无关。在低pH值下，HA/FA的存在促进了Pb2+在β-MnO2上的吸附，而在高pH值下，则降低了Pb2+在β-MnO2上的吸附。铅(II)在β-MnO2上的吸附动力学符合准二级速率方程。根据吸附等温线计算了吸附等温线的热力学参数(增量H度、增量S度和增量G度)，结果表明，铅(II)在β-MnO2上的吸附是一个自发吸热过程。铅(II)在β-MnO2上的吸附是表面络合作用，而不是离子交换作用。(C)2010爱思唯尔B.V.保留所有权利。
In this study, the adsorption of Pb(II) on beta-MnO2 as a function of various environmental conditions such as contact time, pH, ionic strength, humic acid (HA)/fulvic acid (FA), and temperature was investigated using batch techniques. The results indicated that the adsorption of Pb(II) on beta-MnO2 was obviously dependent on pH but independent of ionic strength. The presence of HA/FA enhanced the adsorption of Pb(II) on beta-MnO2 at low pH, whereas reduced Pb(II) adsorption on beta-MnO2 at high pH. The kinetic adsorption of Pb(II) on beta-MnO2 can be well fitted by the pseudo-second-order rate equation. The thermodynamic parameters (Delta H degrees, Delta S degrees, and Delta G degrees) were also calculated from the temperature dependent adsorption isotherms, and the results suggested that the adsorption of Pb(II) on beta-MnO2 was a spontaneous and endothermic process. The adsorption of Pb(II) on beta-MnO2 was attributed to surface complexation rather than ion exchange. (C) 2010 Elsevier B.V. All rights reserved.