Kinetic model for the sorption of copper ions onto sugar beet shreds

Adsorption kinetics is of great significance to evaluate the performance of adsorption process. The kinetics of copper ions adsorption onto different sized sugar beet shreds has been considered. Sugar beet shreds are very promising adsorbents due to their convenient chemical composition and availability in relatively large quantities in many countries. Experimental data were fitted with pseudo-first and pseudo-second-order kinetic models. Also, we used the intraparticle diffusion model for further analysis of kinetics. The coefficient of determination indicates that, the pseudo-second-order equation obtained by using non-linear least square method, was the most appropriate model for the description of copper ions adsorption onto sugar beet shreds. The adsorption capacities at equilibrium, for a particle size of 224 - 400 ?m, 400 - 750 ?m and 750 - 1000 ?m, are 10 mg/g, 9 mg/g and 8.6 mg/g, respectively. By using intraparticle diffusion model proposed by Weber and Morris, it was obtained that there exist two different stages in adsorption: fast initial adsorption which is further limited by intraparticle diffusion.