Sorption of Cu(II), Zn(II) and Ni(II) from aqueous solution using activated carbon prepared from olive stone waste

The performance of olive stone activated carbon (OSAC) for the sorption of Cu^2+, Zn^2+ and Ni^2+ ions was investigated via batch technique. OSAC materials were prepared under different physical activation conditions. Olive stone waste was activated with N2 and steam at 900°C at a 3.5h hold time (OSAC-3). The characterization for OSAC-3 was performed under BET-surface area, SEM, density and FTIR-spectrum. The optimum adsorption conditions were specified as a function of agitation time, initial metal concentration, pH, and temperature. The kinetic results were found to be fast and described well by the pseudo-second order model. The adsorption capacities were 25.38mg/g (Cu^2+), 16.95mg/g (Zn^2+) and 14.65mg/g (Ni2+) which followed the sequence Cu^2+ > Zn^2+ > Ni^2+. The spontaneous adsorption for all the studied cations, endothermic nature for both Zn^2+ and Ni^2+ ions and exothermic nature for Cu^2+ ions were obtained. The results showed that OSAC-3 is an economically feasible material for Cu^2+, Zn^2+ and Ni^2+ remediation from weak acidic contaminated effluents.