探讨了活性白土(AAB)对油脂溶液中β-胡萝卜素的吸附热力学及动力学特征,AAB对β-胡萝卜素的吸附行为可用Langmuir和Freundlich等温式进行描述,相关性均较好,在高温条件下(75~95℃),AAB对β-胡萝卜素的吸附更符合Freundlich模型的吸附行为。分别采用拟一级反应和拟二级反应模型描述了吸附动力学数据,表明AAB吸附β-胡萝卜素适合于拟二级吸附动力学行为,且高温有利于提高吸附量和吸附速率。AAB对β-胡萝卜素的吸附表观活化能Ea为38.673kJ/mol,表明整个吸附过程涉及到化学吸附作用;通过对吸附热力学参数△H、△S及△G的分析,表明吸附过程是自发进行且伴随着吸热及熵值的增加,吸附趋势随着温度的升高而有所增大。
The adsorption behavior of t-carotene in oil solution on acid-activated bentonite (AAB) was investigated. Experimental data of t-carotene adsorption on AAB at different temperatures were agreed well with the Langmuir model and the Freundlich model, while the Freundlich model appeared to fit better experimental data at higher temperatures (75-95℃). Experimental data were described by the pseudo first-order model and the pseudo second-order model, the pseudo second-order model was agreed well on adsorption oft-carotene. Increasing of temperature was favor to enhance the adsorption amount and rate of t-carotene on AAB. 38.673kJ/mol of activation energy of adsorption oft-carotene on AAB indicated that the whole adsorption process was involved in chemical interaction. Various thermodynamic parameters, AH, AS and AG were analysed, the results showed that the adsorption process was spontaneous and endothermic, and accompanied with the entropy increases, the adsorption trend was increased with increasing of temperature.