ADSORPTION-KINETICS OF O-XYLENE BY FLY-ASH

Relatively limited information is available regarding the kinetics of sorption of organic compounds from solution onto flyash. For this reas on, a detailed study of the kinetics of sorption of o-xylene on flyash was conducted in a controlled batch system. The effects of solute con centration, particle size of the adsorbent, and temperature on the ads orption rate were investigated. The results of this research demonstra te that the adsorption reaction can be approximated to first-order rev ersible kinetics. A significant correlation was observed between the r ate of adsorption and the inverse of the square of the particle diamet er. An examination of thermodynamic parameters shows that the adsorpti on of o-xylene by flyash is an exothermic process and is spontaneous a t the temperature investigated. Activation energies for the sorption p rocess ranged between 3.1 and 4.3 kcal/mol. The rate at which o-xylene is adsorbed onto flyash was found to be controlled by the diffusion p rocess. Copyright (C) 1996 Elsevier Science Ltd.