(320af) A Novel and Simple Method for Finding the Heterogeneity of Adsorbent on the Basis of Adsorption Kinetic Data

Rapid grow in industry and population has resulted in environmental degradation; especially water pollution due to toxic compounds is a serious environmental and public problem. Among the various treatments technologies for reduction of pollutants contents, adsorption is one of the most effective methods. Adsorption process includes equilibrium and kinetic aspects. The kinetic of adsorption is one of the fundamental studies necessary for better understanding of mechanism of sorption. Also it is important to be able to predict the rate at which pollutant is removed from aqueous solution in order to design appropriate sorption treatment system. The aim of this work is to present a new method for finding the heterogeneity of adsorbent on the basis of adsorption kinetic data. On the basis of different simulated adsorption kinetic data (for heterogeneous adsorbent) it was found that there is a deviation from linearity in pseudo-second order adsorption kinetic model. The patterns of obtained diagrams show five main classes of adsorption. So that on the basis of this novel and simple method it is possible to show that the surface of adsorbent is homogeneous or heterogeneous and in the case of heterogeneous surface it is possible to find the differences between adsorption sites. For finding of kinetic constants of adsorption on heterogeneous surface, a new equation (two site model) was presented. Finally some experimental kinetic data of adsorption were analyzed by the present method.