Application of modified red mud for adsorption of Acid red 88(AR88) dye from aqueous solution: Isotherms, Kinetics and thermodynamic

This study was aimed to survey the feasibility application of Red mud as adsorbent for the removal of Acid red 88 dye. The efficiency of the adsorbent in removal of dye was studied by investigation of the impact of different parameters such as pH, adsorbent dosage, contact time, initial dye concentration, mixing rate and solution temperature. The experimental data was explained by adsorption isotherms and kinetics. The results indicated that increasing of contact time from 10 to 75 min and adsorbent dosage from 2 to 6 gr/L are led to increase the dye adsorption from 48% to 99.5% and 44% to 99.5%, respectively. The pH value of 3, contact time of 75 min, adsorbent dosage of 6 g/L, dye concentration of 25 mg/L and mixing rate of 200 rpm were determined as optimum conditions. The equilibrium data is best fitted on Langmuir isotherm and the adsorption kinetic model follows pseudo-second model.