Characteristics of Elovich equation used for the analysis of adsorption kinetics in dye-chitosan systems
Characteristics of Elovich equation used for the analysis of adsorption kinetics in dye-chitosan systems
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DOI：
10.1016/j.cej.2009.01.014
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发表时间：
2009-08-01
影响因子：
15.1
通讯作者：
Juang, Ruey-Shin
中科院分区：
文献类型：
--
作者：
Wu, Feng-Chin;Tseng, Ru-Ling;Juang, Ruey-Shin
Elovich方程描述了自然界中的化学吸附（化学反应）机理，在吸附动力学中得到了广泛的应用。用Elovich方程的接近平衡参数（R-E）描述吸附动力学特征曲线。在所考察的64个吸附体系中，80%的吸附体系的R-E值在0.1 ~ 0.3之间，吸附曲线属于“缓升”型。三个实例的计算结果表明，Elovich方程的特征曲线介于Lagergren一级方程和颗粒内扩散模型之间。以对虾壳、龙虾壳和蟹壳为原料制备壳聚糖，并将其用于活性染料的吸附。三种动力学模型的平均偏差表明Elovich方程是最合适的动力学模型。所有吸附体系均处于“温和上升”区。R-E值与原料种类有关，与壳聚糖粒径无关，符合Elovich方程的化学吸附性质。根据提出的最佳吸附剂消耗量85%及其相应的操作时间（t（0.85）），这两个参数可用于工程设计。(C)2009年由Elsevier B. V.出版
The Elovich equation has been widely used in adsorption kinetics, which describes chemical adsorption (chemical reaction) mechanism in nature. The approaching equilibrium parameter of Elovich equation (R-E) was used here to describe the characteristic curves of adsorption kinetics. Of 64 adsorption systems surveyed in this work, 80% of the R-E values were between 0.1 and 0.3 with an adsorption curve belonging to "mild rising". The results of three examples revealed that the characteristic curve of Elovich equation was between those of Lagergren's first-order equation and intraparticle diffusion model. Chitosans prepared from prawn, lobster, and crab shells were used for the adsorption of a reactive dye. The mean deviation obtained from the three kinetic models revealed that Elovich equation was the most suitable one. All the adsorption systems were in the "mild rising" zone. The R-E value was related to the type of raw material but not to the particle size of chitosan, which agreed with chemical adsorption nature of the Elovich equation. According to an optimal adsorbent consumption of 85% coupled with its corresponding operating time (t(0.85)) proposed, these two parameters could be used for engineering design. (C) 2009 Published by Elsevier B.V.