Oubagaranadin John U Kennedy, Sathyamurthy N, Murthy Z V P
Department of Ceramic and Cement Technology, PDA College of Engineering, Gulbarga 585102, Karnataka, India.
J Hazard Mater. 2007 Apr 2;142(1-2):165-74. doi: 10.1016/j.jhazmat.2006.08.001. Epub 2006 Aug 8.
Fuller's earth (FE) has been used as an adsorbent in this work to remove mercury from aqueous solutions. For the purpose of comparison, simultaneous experiments using activated carbon (AC) have also been done. The aim of the work is to test how best FE can be used as an adsorbent for mercury. Equilibrium isotherms, such as Freundlich, Langmuir, Dubinin-Redushkevich, Temkin, Harkins-Jura, Halsey and Henderson have been tested. Kinetic studies based on Lagergren first-order, pseudo-second-order rate expressions and intra-particle diffusion studies have been done. The batch experiments were conducted at room temperature (30 degrees C) and at the normal pH (6.7+/-0.2) of the solution. It has been observed that Hg(II) removal rate is better for FE than AC, due to large dosage requirement, whereas the adsorption capacity of AC is found to be much better than FE. Hence, although FE can be used as an adsorbent, a high dosage is required, when compared to AC. Hybrid fractional error function analysis shows that the best-fit for the adsorption equilibrium data is represented by Freundlich isotherm. Kinetic and film diffusion studies show that the adsorption of mercury on FE and AC is both intra-particle diffusion and film diffusion controlled.
在本研究中，已使用富勒土（FE）作为吸附剂从水溶液中去除汞。为作比较，还同时进行了使用活性炭（AC）的实验。本研究的目的是测试FE作为汞吸附剂的最佳使用方式。已测试了Freundlich、Langmuir、Dubinin-Redushkevich、Temkin、Harkins-Jura、Halsey和Henderson等平衡等温线。基于Lagergren一级、准二级速率表达式进行了动力学研究，并开展了颗粒内扩散研究。间歇实验在室温（30摄氏度）和溶液的正常pH值（6.7±0.2）下进行。据观察，由于所需剂量大，FE对Hg(II)的去除率优于AC，而AC的吸附容量比FE好得多。因此，尽管FE可作为吸附剂，但与AC相比，需要高剂量。混合分数误差函数分析表明，吸附平衡数据的最佳拟合由Freundlich等温线表示。动力学和膜扩散研究表明，汞在FE和AC上的吸附均受颗粒内扩散和膜扩散控制。
