INTERACTION OF L-ASCORBIC ACID WITH ACTIVATED CARBON: KINETIC STUDIES AND THE EFFECT OF pH

Abstract

This article investigates the interaction of vitamin C with commercial activated Granucol-type carbons and newly produced AC-C coal at 25 and 35°C. L-Ascorbic acid molecules have been shown to retain on the surface of coals due to physical interactions. The adsorption kinetics is perfectly described by the pseudo-second-order kinetic model. The adsorption rate is mainly determined by the intraparticle diffusion. The process of adsorption of vitamin C on activated carbon is accompanied by a change in the pH of the system. The absorption is highly dependent on the pH of the solution, decreasing as the pH of the solution increases prior to contact with the carbon. In the carbon phase, ascorbic acid oxidizes to dehydroascorbic acid.