Abstract: The adsorption of glycine on resin D301 in glycine aqueous solution was investigated by static adsorption experiments. The optimum adsorption conditions were found by single factor experiments: adsorbent dosage 0.1 g, pH value of solution 7.5, and temperature 35℃. Under these adsorption conditions, the time required for adsorption equilibrium was 45 min, with the maximal equilibrium adsorption amount as 794.81 mg·g^-1. The thermodynamic performance of the adsorption process was investigated in the range from 303.15 K to 318.15 K. Langmuir, Freundlich and Temkin isothermal adsorption models were employed to fit the experimental data. The results show that the adsorption of glycine on resin D301 is in accordance with the Langmuir isothermal adsorption model. The thermodynamic parameters, such as ΔH^θ, ΔG^θ, ΔS^θ and apparent activation energy, were calculated to be 134.75 kJ·mol^-1,-6.312 kJ·mol^-1, 450.806 J·mol^-1·K^-1, and 81.27 kJ·mol^-1, respectively. The results indicate that the adsorption process of glycine onto resin D301 is a spontaneous endothermic process with physical and chemical adsorption.

Key words: glycine, resin D301, adsorption, thermodynamics, kinetics

摘要： 通过静态吸附法研究了树脂D301对水溶液中甘氨酸的吸附行为。采用单因素实验法确定了最佳吸附条件为pH 7.5，温度35℃，时间45 min，吸附剂用量为0.1 g，在此条件下最大平衡吸附量可达794.81 mg·g^-1。同时探究了D301对甘氨酸溶液吸附的热力学行为，测得了303.15～318.15 K温度范围内的吸附等温线数据，用Langmuir、Freundlich、Temkin方程对此进行拟合，并根据热力学原理计算得到吸附过程中ΔH^θ、ΔG^θ、ΔS^θ值和吸附表观活化能。结果表明等温吸附平衡符合Langmuir等温线模型，其ΔH^θ 134.75 kJ·mol^-1，ΔG^θ-6.312 kJ·mol^-1， ΔS^θ 450.806 J·mol^-1·K^-1，E_a为81.27 kJ·mol^-1。研究结果表明D301对甘氨酸的吸附为化学吸附和物理吸附共存且为自发进行的吸热过程。

关键词: 甘氨酸, D301树脂, 吸附, 热力学, 动力学