Eren Erdal
Department of Chemistry, Ahi Evran University, Faculty of Arts and Science, 40100 Kirşehir, Turkey.
J Hazard Mater. 2009 Mar 15;162(2-3):1355-63. doi: 10.1016/j.jhazmat.2008.06.016. Epub 2008 Jun 13.
The adsorption behavior of crystal violet (CV(+)) from aqueous solution onto raw (RB) and manganese oxide-modified (MMB) bentonite samples was investigated as a function of parameters such as initial CV(+) concentration, contact time and temperature. The Langmuir, Freundlich and Dubinin-Radushkevich (D-R) adsorption models were applied to describe the equilibrium isotherms. The Langmuir monolayer adsorption capacities of RB and MMB were estimated as 0.32 and 1.12 mmol/g, respectively. The mean adsorption energy derived from D-R isotherm for MMB showed that the type of adsorption of dye molecules on this material may be defined as chemical adsorption. The adsorption rate was fast and more than half of the adsorbed-CV(+) was removed in the first 55 min for RB and 5 min for MMB at the room temperature. The pseudo-first-order, pseudo-second-order kinetic and the intraparticle diffusion models were used to describe the kinetic data and rate constants were evaluated. The thermodynamic parameters such as DeltaH, DeltaS and DeltaG were found 117.41 kJ/mol, 41.50 J/(molK), -5.07 kJ/mol (RB) and 21.19 kJ/mol 98.34 J/(molK), -7.84 kJ/mol (MMB) at 295.15 K, respectively. The quite high adsorption capacity and high adsorption rate of MMB will provide an important advantage for using of this material in basic dye solution.
研究了水溶液中结晶紫（CV(+)）在未改性膨润土（RB）和氧化锰改性膨润土（MMB）上的吸附行为，考察了初始CV(+)浓度、接触时间和温度等参数的影响。应用朗缪尔、弗伦德利希和杜比宁-拉杜舍维奇（D-R）吸附模型描述平衡等温线。RB和MMB的朗缪尔单层吸附容量分别估计为0.32和1.12 mmol/g。由MMB的D-R等温线得出的平均吸附能表明，染料分子在该材料上的吸附类型可定义为化学吸附。吸附速率很快，在室温下，RB在前55分钟内去除了超过一半的吸附CV(+)，MMB在前5分钟内去除了超过一半的吸附CV(+)。采用准一级、准二级动力学和颗粒内扩散模型描述动力学数据并评估速率常数。在295.15 K时，RB的热力学参数ΔH、ΔS和ΔG分别为117.41 kJ/mol、41.50 J/(mol·K)、-5.07 kJ/mol，MMB的热力学参数分别为21.19 kJ/mol、98.34 J/(mol·K)、-7.84 kJ/mol。MMB相当高的吸附容量和高吸附速率将为该材料在碱性染料溶液中的应用提供重要优势。
