Adsorption of heavy metal ions from aqueous solutions by MgCl_2 modified orange peel

Orange peel(OP) was modified by MgCl2 to prepare a novel orange peel adsorbent named as MgOP.The effects of pH,temperature,solid/liquid ratio,adsorption time and metal ion concentration on the removal behavior of individual heavy metals such as Cu2+,Cd2+,Pb2+,Zn2+ and Ni2+ from aqueous solution with single component by MgOP were investigated.The results show that pH and solid/liquid ratio have positive effects on the adsorption efficiency;temperature has little impact on the adsorption efficiency.All adsorption processes can attain equilibrium within 20 min,and the kinetics data of five kinds of metal ions are fitted to pseudo-second-equation.The MgOP can increase the maximum adsorption capacities of Cu2+,Cd2+,Pb2+,Zn2+ and Ni2+,compared with those of OP.The MgOP can be used for more than 10 cycles.The effect of coexisting metal ions on adsorption can be neglected.