Adsorption of Pb2+ and Cu2+ with Unburned Desulphurization Slag Modified Nickel Slag

Desulphurization slag modified nickel slag adsorbent was prepared by unburned forming technology. The structure of the sample was characterized by BET, XRD, IR, SEM and EDAX. The adsorption performance of Pb2+ and Cu2+ onto the resultant adsorbent from aqueous solution was studied. Results indicated that the adsorbent possesses a network pore structure formed by the AFt and C-S-H through cross lapping; the adsorbent contains a large number of Si-OH and Al-OH functional groups. The presence of functional groups not only provides abundant adsorption sites for Pb2+ and Cu2+, but also improves the adsorption performance of Pb2+ and Cu2+ from waste water through the complexation of heavy metal ions. The result of specific surface area analysis showed that the adsorbent sample possesses mesoporous structure and the BET specific surface area is 27.15 m(2)/g. The solution pH values for the adsorption of Pb2+ and Cu2+ were optimized to be 6 and 5.5, respectively. The adsorption capacities of Pb2+ and Cu2+ gradually increase, whereas the removal rates of the two metal ions decrease with increasing the initial concentration of simulated solution. The resultant adsorbent gives a higher adsorption capacity for Cu2+ than for Pb2+ in the single ion solution. However, it shows preferential adsorption of Pb2+ rather than that of Cu2+. Meanwhile, results of recyclability indicate the remarkable regeneration capacity, re-adsorption ability and reusability performance of the adsorbent sample.