Synthesis of zeolite Y from diatomite and its modification by dimethylglyoxime for the removal of Ni(II) from aqueous solution

Zeolite Y was obtained from diatomite in a template-free system, and the product was modified by dimethylglyoxime. Characterization studies indicate that the DMG molecules were loaded onto both the exterior surfaces and channels of the zeolite Y during the modification process. Removal of Ni(II) by modified samples was investigated in batch procedure, and it was found that the modified zeolite Y has a very high capacity. The effects of various parameters such as sorbent content, contact time, concentration of nickel solution, pH and selectivity were discussed. The best removal efficiency was observed by Y-DMG at the following experimental conditions: Y-DMG dosage: 2 g L-1, C-Ni(II): 100 mg L-1 and contact time: 9 h. The Y-DMG sorbent shows good efficiency for the removal of nickel in the presence of different multivalent cations. Adsorption kinetics based on the pseudo-second-order rate equation indicates that the rate-limiting step involves chemical reaction. Adsorption isotherms of Ni(II) ions obey Langmuir equation which indicates the monolayer sorption of Ni(II). The results of thermodynamic parameters of Ni(II) on Y-DMG indicate the process was endothermic and spontaneous.