Preparation of Activated Carbon from Waste Tire Rubber for the Active Removal of Cr(VI) and Mn(II) Ions from Aqueous Solution

The activated carbon adsorbent was synthesized from waste tire rubber through pyrolytic technique and characterized by CHNS elemental analysis, BET, XRD, FESEM-EDX and FTIR spectra. The adsorption of Cr(VI) and Mn(II) ions on thus obtained adsorbent was investigated separately by varying experimental parameters, such as pH, adsorbent dose, contact time, adsorbate ion concentration and temperature. The adsorption processes were found to be the best fitted in Langmuir adsorption isotherm model controlled by pseudo-second-order kinetics. The Cr(VI) and Mn(II) ions adsorption capacity of AC were 14.45 and 3.04 mg.g(-1), respectively. The rate constants for the adsorptions of Cr(VI) and Mn(II) ions were 5.88x10(-1) and 3.95x10(-1) g.mg(-1).min(-1), respectively. The thermodynamic study revealed the adsorption processes to be spontaneous.