removal of cr(iii), mn(ii), fe(iii), ni(ii), cu(ii), zn(ii), and pb(ii) from water solutions using activated carbon based on cherry kernel shell powder

In this work, a method for preparing activated carbon based on cherry kernel shell (ac-cks) was investigated using two consecutive steps: chemical activation with h2so4 agent and thermal activation in air. for the first time, ac-cks product is used for the removal of numerous metal ions such cr(iii), mn(ii), fe(iii), ni(ii), cu(ii), zn(ii), and pb(ii) from water solutions. the ac-cks was characterized using ea, ft-ir, sem, edx, and xrf techniques. the ac-cks obtained by heating at 600 °c showed products with higher iodine numbers and invariably micro-size pores compared to those obtained by heating at 55°c and 400°c. the adsorption capacity of ac-cks600 was tested in the removal of previously mentioned metal ions. the essential parameters affecting the removal of metal ions were studied. the results showed maximum adsorption of 99.0% for cr(iii), 91.7% for fe(iii), 62.0% for cu(ii), 59.3% for pb(ii), 42.0% for zn(ii), 28.0% for ni(ii), and 26.9% for mn(ii). the adsorption data of most metal ions fitted well with langmuir model. the maximum adsorption capacity followed the sequence: cr(10.75mg/g)>fe(10.15mg/g)>cu(7.58mg/g)>pb(7.36mg/g)>zn(6.08mg/g)>ni(2.83g/g)>mn(2.29 mg/g). the adsorption kinetics was tested for the pseudo-first order and pseudo-second order.the rate constants of adsorption for all studied metal ions were calculated. good correlation coefficients (r²>0.9972) were obtained for the pseudo-second-order kinetic model showing that all metal ions uptake processes followed the pseudo-second-order rate expression. desorption studies showed the quantitative recovery of metal ions in the range of 89.4% for pb(ii) to 94% for cr(iii). according to the adsorption model applied in this work, ac-cks600 product could be recommended for the removal of cr(iii), fe(iii), cu(ii), pb(ii), and zn(ii) from aqueous solutions.