Adsorption kinetic's of beta-carotene and chlorophyll onto acid-activated bentonite in model oil

作者:Tong Junmao; Wu Zhansheng; Sun Xifang; Xu Xiaolin; Li Chun*
来源:Chinese Journal of Chemical Engineering, 2008, 16(2): 270-276.
DOI:10.1016/S1004-9541(08)60074-9

摘要

The textural properties of acid-activated bentonite (AAB), which were prepared using four different concentrations of sulfuric acid, were analyzed by adsorption-desorption isotherm of nitrogen using an automated specific surface area and porosity analyzer. The total pore volume, specific surface area and average pore diameter of these four kinds of AAB show a regular changing trend, increasing first and then decreasing, the optimum of which can be achieved at a sulfuric acid concentration of 25% (sample A25). The kinetic analysis of the adsorption of beta-carotene and chlorophyll in model oil solutions, namely, xylene and edible oil solution, has been investigated by using AAB. Experimental results indicated that the adsorption data fit the pseudo-second-order model well. The whole adsorption process of the two pigments on AAB was divided basically into two parts: the initial adsorption of pigments was rapid in the first 10 min, followed by a slower adsorption process till equilibrium was attained at 60 min. In addition, the amount and rate of adsorption on A25 increase synchronously with the initial pigment concentration and temperature. The results showed that the adsorption kinetics behavior of AAB with respect to the pigments is not influence by the xylene and edible oil solution.