通过静态吸附实验,研究了l-色氨酸在001x7型阳离子交换树脂上的等温吸附和吸附动力学特性。采用动边界模型描述l-色氨酸在该树脂上的交换行为,考察了料液浓度、树脂粒径和温度对交换过程的影响。结果表明,l-色氨酸在001x7型阳离子交换树脂上的吸附等温线符合lAngMuIr等温方程,且随PH降低,树脂的最大平衡吸附量逐渐增大;交换过程的吸附速率随l-色氨酸浓度和温度的升高而增大,但随树脂粒径的增大而减小;离子交换过程的速度控制步骤为颗粒扩散控制。交换过程的反应速率常数k0为1.199x10 5,反应级数为1.7,表观活化能EA为19.94kJ MOl 1,并得到了动力学总方程式。The isothermal adsorption and adsorption kinetics of L-tryptophan by 001×7 cation-exchange resin were studied by static experiments.The Moving Boundary Model was applied to describe the kinetics of the ion exchange process.The effects of experimental conditions including the concentration of L-tryptophan,resin particle diameter and adsorption temperature on the ion exchange process were investigated.The results show that the maximum L-tryptophan adsorption capacity of 001×7 cation-exchange resin increases with decreasing solution pH.It was found that the Langmuir equation fits the adsorption isotherm data best,and the particle diffusion is the rate-limiting step of the adsorption process.The adsorption ratio increases with the increase of L-tryptophan concentration and adsorption temperature,but decreases with the increase of the resin particle diameter.The rate constant of exchange(k0),reaction order() and the apparent activation energy of reaction(Ea) were obtained as follows: k0=1.199×10 5,Ea=19.94 kJ mol 1,and the kinetics equation was obtained too.国家自然科学基金(3107488);福建省自然科学基金(2011J01058);中央高校基本科研专项基金(2011121017
