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 sorption of cu2+, zn2+ and ni2+ ions was investigated via batch technique. osac materials were prepared under different physially activation conditions. olive stone waste was physically activated with n2 gas and steam gas at 900oc at 3.5h hold time (osac-3) was choice as the best one for cu2+, zn2+ and ni2+ removal. characterization for osac-3 were performed under bet-surface area, sem, density and ftir-spectrum. optimum adsorption conditions were specified as a function of agitation time, initial metal concentration, ph and temperature. kinetic results were found to be fast and described well by the pseudo-second order model. the adsorption capacities are 25.38mg/g (cu2+), 16.95mg/g (zn2+) and 14.65mg/g (ni2+) which followed the sequence cu2+ > zn2+ > ni2+. spontaneous adsorption for all the studied cations, endothermic nature for both zn2+ and ni2+ ions and exothermic nature for cu2+ ions were obtained. the results showed that osac-3 is a good economical material for cu2+, zn2+ and ni2+ remediation from weakly acidic contaminated effluents.