Optimization of the selective adsorpti̇on of Cu+2 from multi-ion aqueous solution (Cu2+, Zn2+ and Ni2+) by ultrasound-assisted preparation of activated carbon from alkaline impregnated hazelnut shells

Optimization of selective adsorption of Cu2+ from multi-ion media (Cu2+, Zn2+ and Ni2+) on activated carbons prepared from 10 % KOH impregnated hazelnuts by ultrasound 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 modeled 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.