Comparison of the generalized and preset-order kinetic equations for description of biosorption data

Abstract

© 2018 University of Novi Sad, Faculty of Technology. All rights reserved. Time course of adsorption of the different pollutants from water is the basis in the testing of an adsorbent. Over the years, several kinetics models have been proposed. Nevertheless, pseudo-first-order and pseudo-second-order kinetic models are by far the most used in the testing. Since various biological materials have complex composition, it is assumed that the adsorption kinetics on such materials, named biosorbents, can not be described sufficiently well by these two models. In this paper, both generalized and preset order kinetic equations were applied on the results of copper and chromium ions adsorption onto spent brewer’s grain. The biosorption of copper ions corresponds the best to the 2.5, and biosorption of chromium ions to the 4.9 reaction order. The analyses of the kinetic tests results on different biosorbents conducted by other authors indicate that the determination of the reaction order should be obtained by generalized kinetic model. It was also established that the f value (relative goodness of curve fitting) was better for the prediction which equations is better, than the R value (correlation coefficient).