The reactive blue 4 (RB4) dye adsorption onto chitosan 10B was studied in aqueous solution as a function of contact time, dye concentrations, ionic strength, temperature and solution pHs. The dye adsorption kinetics validated a pseudo second-order model while the rate determining step followed intraparticle diffusion mechanism. The equilibrium dye adsorption isotherms were nicely fitted with the Langmuir model. The maximum amount of dye uptake onto chitosan 10B was found to be 95.24 μmol/g. The mean adsorption energy ( E ) from the Dubinin–Radushkevich isotherm, the activation energy ( E _a) from Arrhenius equation and apparent thermodynamic parameters such as changes in standard free energy (∆ G °), standard enthalpy (∆ H °) and standard entropy (∆ S °) indicate that the present adsorption is a spontaneous endothermic physisorption process. Desorption of RB4 from dye-loaded chitosan was tested in NaOH solution (pH 13) and the chitosan flakes can be reused.

中文翻译：

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壳聚糖10B在水溶液中吸附活性蓝4染料：动力学建模和等温线分析

研究了在水溶液中吸附到壳聚糖10B上的活性蓝4（RB4）染料与接触时间，染料浓度，离子强度，温度和溶液pH的关系。染料吸附动力学验证了伪二级模型，而速率确定步骤遵循粒子内扩散机制。平衡染料吸附等温线与Langmuir模型很好地拟合。发现染料在壳聚糖10B上的最大摄取量为95.24μmol/ g。Dubinin–Radushkevich等温线的平均吸附能（ E ），Arrhenius方程的活化能（ E _a）和表观热力学参数，例如标准自由能（∆ G °），标准焓（∆ H）的变化 °）和标准熵（ ΔS °）表明当前的吸附是自发的吸热物理吸附过程。在NaOH溶液（pH 13）中测试了负载染料的脱乙酰壳多糖中RB4的解吸，该脱乙酰壳多糖薄片可重复使用。