Adsorption of reactive dye onto cross-linked chitosan/oil palm ash composite beads
Adsorption of reactive dye onto cross-linked chitosan/oil palm ash composite beads
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DOI：
10.1016/j.cej.2007.03.038
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发表时间：
2008-03-01
影响因子：
15.1
通讯作者：
Hameed, B. H.
中科院分区：
文献类型：
--
作者：
Hasan, M.;Ahmad, A. L.;Hameed, B. H.
研究了交联壳聚糖/油棕灰复合微球（CC/OPA）对水溶液中活性染料的吸附性能。通过考虑各种参数的影响，如初始浓度（50-500 mg/L）、接触时间、pH（2-13）和温度（30、40、50 ℃），进行动力学和等温线研究。结果表明，酸性溶液中的染料上染率远高于中性和碱性溶液。采用Langmuir、Freundlich、Redlich-Peterson和Temkin等温线分析了不同温度下的平衡数据。Redlich-Peterson等温线对实验数据的拟合明显优于其他等温线。吸附动力学数据进行了测试，使用伪一级和伪二级模型。动力学研究表明，吸附遵循准二级模型。对不同初始浓度下的拟一级和拟二级反应速率常数进行了计算和讨论。热力学参数，如标准吉布斯自由能（Δ G度），标准焓（Δ H度），和标准熵（Δ S度）通过应用范特霍夫方程进行了评估。交联壳聚糖/油棕灰复合微球吸附活性染料的热力学研究表明，该吸附过程是自发的吸热过程。(c)2007 Elsevier B.V保留所有权利。
Adsorption of reactive dye from aqueous solution onto cross-linked chitosan/oil palm ash composite beads (CC/OPA) was investigated in a batch system. Kinetic and isotherm studies were carried out by considering the effects of various parameters, such as initial concentration (50-500 mg/L), contact time, pH (2-13), and temperature (30,40, 50 degrees C). It was found that the dye uptakes were much higher in acidic solutions than those in neutral and alkaline conditions. Langmuir, Freundlich, Redlich-Peterson, and Temkin isotherms were used to analyze the equilibrium data at different temperatures. The Redlich-Peterson isotherm fits the experimental data significantly better than the other isotherms. Adsorption kinetics data were tested using pseudo-first-order and pseudo-second-order models. Kinetic studies showed that the adsorption followed a pseudo-second-order model. The pseudo-first-order and pseudo-second-order rate constants for different initial concentrations were evaluated and discussed. Thermodynamic parameters such as standard Gibbs free energy (Delta G degrees), standard enthalpy (Delta H degrees), and standard entropy (Delta S degrees) were evaluated by applying the Van't Hoff equation. The thermodynamics of reactive dye adsorption onto cross-linked chitosan/oil palm ash composite beads indicates its spontaneous and endothermic nature. (c) 2007 Elsevier B.V All rights reserved.