In order to determine the adsorption characteristics of congo red by biosorbent chitosan,we studied the effects of pH,initial concentration,contact time and temperature.The result showed that the biosorption of congo red was significantly affected by initial solution pH,and the optimal pH of biosorption was 4 ～7.The kinetics of the interactions showed better agreement with the Lagergren second order kinetics,and indicated that capacity decreased with increasing temperature.The activation energy of biosorption (Ea) was determined to be 2.90 kJ/mol using Arrhenius equation.The adsorption data showed a good fit with Freundlich isotherm equation.Thermodynamic parameters,such as AG° and AH° were found as-10.10 kJ/mol (303 K) and-87.36 kJ/mol,respectively.The results indicated that the adsorption of congo red by chitosan was spontaneous and exothermic.The FTIR data showed that some functional groups mainly including-OH and-NH2 in chitosan were responsible for the adsorption of congo red.%为了确定生物吸附剂壳聚糖对刚果红的吸附行为特征,研究了pH值、初始浓度、时间及温度对刚果红在壳聚糖上吸附的影响.结果表明,pH值是影响壳聚糖吸附刚果红的重要因素,最佳pH值范围为4～7;动力学行为符合Lagergren准二级反应动力学模型,随着温度增加,平衡吸附量减少.吸附过程的表观活化能(Ea)为4.941 kJ/mol.壳聚糖对刚果红的吸附过程较好地符合Freundlich吸附等温方程.计算得到吸附过程的热力学参数ΔG°和ΔH°分别为-10.10 kJ/mol(303 K)和-87.36 kJ/mol,表明壳聚糖对刚果红的吸附是一个自发的放热过程.红外光谱分析可知,壳聚糖吸附刚果红的过程中,壳聚糖分子中存在的大量羟基和氨基发挥了主要作用.
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