ABSTRACT
In this research, waste tyre rubber was used for activated carbon production with a novel route by modified physo-chemical approach. Potassium hydroxide and carbon dioxide were selected as chemical and physical activating agents, respectively and the process was carried out without carbonization under inert atmospheric conditions. The experiments were designed by applying the central composite design (CCD) as one of the subsets of response surface methodology (RSM). The effects of activation temperature (550-750 °C), activation time (15-75 min), impregnation ratio of KOH/rubber (0.75-3.75) and CO2 flow rate (200-400 mL/min) on production yield and specific surface area of produced activated carbon were studied. Based on the results, the 2FI and quadratic models were selected for production yield and specific surface area, respectively. The activation temperature was the main effective parameter on both responses in this process. The production yield and specific surface area of produced activated carbon at optimized conditions for each model were 47% and 928 m2/g, respectively. BET, XRF, XRD, FT-IR, EDS and FE-SEM analyses were carried out on the optimized sample of specific surface area model in order to investigate the residual salts and morphological porous structures. Based on the surface properties and the presence of sulfur compounds in produced activated carbon, this activated carbon has the ability of eliminating heavy metals such as mercury from industrial waste water.
