Earth Dynamic System Research Center, National Cheng-Kung University, No. 1, University Road, Tainan City 701, Taiwan, ROC.
J Hazard Mater. 2012 Oct 15;235-236:116-22. doi: 10.1016/j.jhazmat.2012.07.030. Epub 2012 Jul 20.
Magnetic nano-particles CuFe(2)O(4) were successful manufactured from industrial sludge by combination of acid leaching, chemical exchange, and ferrite process. For the first time these recycled nano-particles were used as adsorbent to investigate the kinetics and thermodynamics for adsorption of Cd in aqueous solutions. These experimental results showed that Cd(2+) adsorption efficiency increased from 0.85 to 99.9% when pH increased from 2 to 6. The maximum adsorption capacity of Cd(2+) was found to be 17.54 mg g(-1) under the conditions at pH 6.0, contact time 30 min, and temperature 318 K. The pseudo-second-order kinetic model provides the best correlation with the experimental data compared to the pseudo-first-order model. The Langmuir model yields a better fitting than the Freundlich model for Cd(2+) adsorption on CuFe(2)O(4) nano-particles under investigated temperatures. The thermodynamic constants of the adsorption process were evaluated, ΔG°, ΔH° and ΔS° is -6.05 kJ mol(-1) (at 318 K), 0.71 kJ mol(-1), and 4.53 J mol(-1) K(-1), respectively. These results imply that Cd(2+) adsorption onto CuFe(2)O(4) is feasible, spontaneous and endothermic in nature.
采用酸浸、化学交换和铁氧体法，成功地从工业污泥中制备出磁性纳米粒子 CuFe(2)O(4)。这些回收的纳米粒子首次被用作吸附剂，用于研究水溶液中 Cd 的吸附动力学和热力学。实验结果表明，当 pH 值从 2 增加到 6 时，Cd(2+)的吸附效率从 0.85 增加到 99.9%。在 pH 值为 6.0、接触时间为 30 min、温度为 318 K 的条件下，Cd(2+)的最大吸附容量为 17.54 mg g(-1)。与伪一阶模型相比，拟二阶动力学模型与实验数据的相关性更好。在研究温度下，Langmuir 模型比 Freundlich 模型更适合 Cd(2+)在 CuFe(2)O(4)纳米粒子上的吸附。评估了吸附过程的热力学常数，吸附过程的热力学常数分别为-6.05 kJ mol(-1)（在 318 K 时）、0.71 kJ mol(-1)和 4.53 J mol(-1) K(-1)。这些结果表明，Cd(2+)在 CuFe(2)O(4)上的吸附是可行的、自发的和吸热的。
