Adsorption kinetics of o-xylene by flyash

Relatively limited information is available regarding the kinetics of sorption of organic compounds from solution onto flyash. For this reason, a detailed study of the kinetics of sorption of o-xylene on flyash was conducted in a controlled batch system. The effects of solute concentration, particle size of the adsorbent, and temperature on the adsorption rate were investigated. The results of this research demonstrate that the adsorption reaction can be approximated to first-order reversible kinetics. A significant correlation was observed between the rate of adsorption and the inverse of the square of the particle diameter. An examination of thermodynamic parameters shows that the adsorption of o-xylene by flyash is an exothermic process and is spontaneous at the temperature investigated. Activation energies for the sorption process 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 process.