Use of Natural and Modified Jordanian Zeolitic Tuff for Removal of Cadmium(II) from Aqueous Solutions

The possibility of using natural and modified Jordanian zeolite for removal of cadmium as a model component of heavy metals has been considered. Bench-scale tests using both aqueous solutions and real water under different experimental conditions have been employed. Different parameters, including metal ion concentration, modifier type, water quality and pH, have been studied. Synthetic Zeolite Molecular Sieve (4A) as control material has been also considered for the purpose of comparison. Zeolite characterization has been investigated via XRD, XRF, BET Surface Area/pore size, TGA, FTIR analyses for the samples under consideration. The metal concentration and modification salts were found to have significant effect on sorption of cadmium by zeolite and thus on zeolite efficiency. Hardness in water was found to highly impede adsorption. Sorption equilibrium was achieved within 250 min. The equilibrium isotherm data of cadmiumzeolitic tuff were represented by Langmuir and Freundlich isotherm models, but they were well represented by Langmuir model.