Optimization of selective adsorption of Cu2+ from multi-ion media containing Cu2+, Zn2+ and Ni2+ on activated carbons prepared from ultrasound-assisted 10 % KOH impregnated hazelnut shells was investigated. The effects of independent variables such as particle size, ultrasound power density, impregnation rate, impregnation time, activation temperature and activation time for the production of suitable activated carbons were investigated by experiments with partial factorial design and central composite design. At the end of the adsorption experiments, activated carbons were evaluated by their adsorption capacities. In addition, the results were statistically modelled and optimized using a constrained optimization program via Matlab computer software. Optimum preparation conditions were obtained as follows particle size 1.75 mm, ultrasound power/volume 2 W/L, impregnation ratio 0.0168 g/mL, impregnation time 132 min, activation temperature 661°C and activation time 71,5 min, following with maximum adsorption capacity was found as 82,9 mg Cu2+/g Ac. On the basis of the distribution coefficient (Kd), the selectivity sequence for the multi-ion system of the prepared activated carbons is generally Cu+2 > Zn+2 > Ni+2. As a result, ultrasound-assisted prepared activated carbons can be used effectively to selectively adsorb Cu+2 from multiple ion systems.
Activated carbon, adsorption, multi-ion system, selectivity