Tang Xiao W, Li Zhen Z, Chen Yun M, Wang Yan
Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou, PR China.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2008 Jun;43(7):779-91. doi: 10.1080/10934520801960144.
This paper dealt with the characteristics of Cu(II) adsorption on Chinese Quaternary loess. The Cu(II) adsorption isotherm and kinetics fit the Langmuir model and pseudo-second order kinetics well, respectively, with a predicted adsorption capacity of 109 mg g(-1). The adsorption is ion exchange adsorption due to D-R model. Factors that are positively correlated with the adsorption capacity of loess include equilibrating time, pH, temperature, and solid-solution ratio. The adsorption of Cu(II) on loess involves 2-3 sequential diffusing steps into the micropores, and an endothermic and spontaneous process with predicted enthalpy, entropy, and Gibb's free energy changes of 7.64 kJ mol(-1), 81.21 J mol(-1)K(-1) and -14.94-17.37 kJ mol(-1), respectively. Moreover, the applicability of loess on industrial wastewater treatment was investigated and satisfactorily proved. Finally, FT-IR spectra shows the precipitation of copper carbonate and the complexation of Cu(II) with clay minerals at pH > 5.0 and pH > 2.67, respectively.
本文研究了Cu(II)在中国第四纪黄土上的吸附特性。Cu(II)吸附等温线和动力学分别很好地拟合了Langmuir模型和准二级动力学，预测吸附容量为109 mg g(-1)。根据D-R模型，吸附为离子交换吸附。与黄土吸附容量呈正相关的因素包括平衡时间、pH值、温度和固液比。Cu(II)在黄土上的吸附涉及2 - 3个连续的向微孔扩散步骤，是一个吸热且自发的过程，预测的焓变、熵变和吉布斯自由能变化分别为7.64 kJ mol(-1)、81.21 J mol(-1)K(-1)和 -14.94 - 17.37 kJ mol(-1)。此外，研究了黄土在工业废水处理中的适用性并得到了满意的证明。最后，傅里叶变换红外光谱表明，分别在pH > 5.0和pH > 2.67时，有碳酸铜沉淀以及Cu(II)与粘土矿物发生络合作用。
