溶液中褐藻胶低聚糖在活性炭上的吸附特性与机制研究

Study on the characteristics and mechanism for adsorption ofalginate oligosaccharides on activated charcoal

本文研究了不同pH、反应时间、温度、初始糖浓度条件下溶液中褐藻胶低聚糖(AOS)在活性炭上的吸附性能及其吸附动力学和热力学机制。结果表明,溶液pH对活性炭吸附AOS具有重要影响,随pH降低,AOS在活性炭上的吸附增强,pH=1时吸附量可达0.116 g/g。吸附反应在5 min内迅速发生,60 min后达到吸附平衡。活性炭吸附AOS符合准二级吸附动力学过程。吸附热力学研究表明,吸附过程为自发的放热反应,吸附等温线符合Langmuir模型。综上,吸附过程为单分子层均相吸附,降低pH、低温有利于AOS在活性炭上的吸附。

This study investigates the adsorption characteristics of alginate oligosaccharides(AOS)on activated charcoal at different pH values,contact times,temperatures,and initial AOS concentrations,and examines the kinetic and thermodynamic mechanisms of adsorption.The results of this study show that the pH value of the solution has a considerable effect on the adsorption of AOS on activated charcoal.The adsorption capacity increases with the decrease in pH,reaching up to 0.116 g/g at a pH value of 1.The adsorption occurred rapidly in the first 5 min and reached equilibrium after 60 min.The adsorption can be best described with a pseudo second-order kinetic model.The thermodynamic study reveals the spontaneous and exothermal characteristics of the adsorption,which are better suited to the Langmuir isotherm model.In conclusion,the adsorption of AOS on activated charcoal is homogeneous monolayer adsorption.Lower pH and temperature values are beneficial for adsorption.