8Bayat B. Combined removal of zinc(Ⅱ) and cadmium(Ⅱ) from aqueous solution by adsorption onto high alcium trukish fly ash[J]. Water Air and Soil Pollution, 2002, 136 (1/4): 69-92
9Wan Ngah W S, Kamari A, Koay Y J, Equilibrium and kinetics studies of adsorption of copper (Ⅱ) on chitosan and chitosan/PVA beads[J]. International Journal of Biological Macromolecules, 2004, 34:155-161