Departamento de Química, Instituto Nacional de Investigaciones Nucleares, A. P. 18-1027, Col. Escandón, Delegación Miguel Hidalgo, C.P. 11801 México, D. F., Mexico.
J Environ Manage. 2012 Apr 30;97:6-13. doi: 10.1016/j.jenvman.2011.11.010. Epub 2011 Dec 24.
In the present study the process of adsorption of cadmium from aqueous solutions using Na-zeolitic tuff, Fe-zeolitic tuff and carbonaceous material from pyrolyzed sewage sludge treated with HCl was investigated. The cadmium removal efficiency was studied as a function of contact time, adsorbate concentration, pH and adsorbent dose. The results showed that removal of cadmium was best described by the Langmuir-Freundlich isotherm. The kinetic experimental results were best described by the pseudo-first order model. The results indicate that the adsorption mechanism is physical and chemical sorption on heterogeneous materials. The maximum retention of cadmium was at pH around 6.0 for the materials. In kinetic studies, the Na and Fe modified zeolitic tuffs showed similar sorption capacities for cadmium and they were higher than the capacity found for carbonaceous material.
本研究采用 HCl 处理的热解污水污泥制备的 Na-沸石、Fe-沸石和碳质材料，考察了从水溶液中吸附镉的过程。研究了接触时间、吸附物浓度、pH 值和吸附剂用量对镉去除效率的影响。结果表明，镉的去除最好用 Langmuir-Freundlich 等温线来描述。动力学实验结果最好用伪一级模型来描述。结果表明，吸附机制是在多相材料上的物理和化学吸附。对于这些材料，最大的镉保留率出现在 pH 值约为 6.0 时。在动力学研究中，Na 和 Fe 改性沸石显示出对镉的相似的吸附能力，它们高于碳质材料的吸附能力。
