Characterization of chromium (III) removal from water by river bed sediments - kinetic and equilibrium Studies

In the present study,chromium sorption capacity was investigated in surface sediments derived from two rivers located in the northeast of algeria. adsorption experiments were undertaken in batch; kinetic and equilibrium studies of cr(iii) removal from aqueous solutions were carried out and the ph effect was evaluated. drx and ftir analysis of the studied sediments reveal the predominance of quartz,calcite,illite and kaolinite. the sediment characterized by the highest quartz quantity has the less adsorption capacity for chromium. in order to understand the kinetics of cr(iii) removal by the sediments,three models are tried. finally,the second order model is found suitable for describing the experimental data. the rate constants of adsorption for the two sediments are found to be 9.8×10-3 mg-1.g.min and 4.5×10-3 mg-1.g.min respectively. the adsorption data isotherms are successfully modeled by temkin equation. the calculated constants (l.mg-1) are 4.36 and 5.59 for the two sediments respectively. the chromium uptake increases with ph increasing.