Chemical Engineering Communications, Vol.201, No.2, 191-208, 2014
Use of Response Surface Methodology to Study the Combined Effect of Various Parameters on Hexavalent Chromium Adsorption
Response surface methodology (RSM) was applied as an experimental design for evaluating the effect of various operational parameters, namely contact time, pH, adsorbent dose, and initial adsorbate concentration, on hexavalent chromium (Cr(VI)) ion uptake from aqueous synthetic chromium solutions using granular activated carbon (GAC). Furthermore, the optimized processing conditions for adsorption of chromium on activated carbon were found on the basis of a multiple-response method called desirability. The best chromium removal was achieved at pH of 2.1, adsorbent dose of 5.16g, and initial chromium concentration of 36.49mgL(-1) for a contact time of 239.86min. Also, investigations were carried out to determine the appropriate adsorption isotherm, kinetics models, and mass transfer coefficient of chromium (VI) adsorption on GAC in optimum conditions. The obtained results showed that the adsorption of chromium (VI) follows the Langmuir isotherm equation. In addition, the kinetics of the adsorption process follows pseudo-first-order kinetics.