Adsorption Isotherm Modeling of Toxic Heavy Metals (Pb (II)) from Wastewater by Clay Minerals

Adsorption has been shown to be an economically and environmentally acceptable method for removing toxic heavy metals from water and wastewater. In the present study we want to investigate the feasibility of using natural and synthetic clay minerals in removing Lead ions from synthetic wastewater samples. Effects of various operational parameters such as: initial pH of solution, operating temperature, salinity and presence of other ions with lead ions in the solution, and effects of clay types on adsorption efficiency have been investigated in laboratory. The ion adsorption potential of Commercial Bentonite and Kaolinite was investigated and their adsorption abilities were compared. Lead adsorption ability of clay minerals increased by increasing pH and temperature. Affinity of negatively charged clay particles to adsorb cations depends on solvated ion size. Lead adsorption ability of clay minerals increases with increasing the size of other existing ions. The most important parameter that affects Pb(II) sorption on clay particle surface was found to be pH of the solution. Data from adsorption experiments were used to see the fitness of experimental data by two common mathematical models, Langmuir and Freundlich isotherm models. Experimental data were almost fitted with the Langmuir and Freundlich isotherms in all cases.

کلیدواژه ها:

Langmuir and Freundlich Isotherm Models ، Clay Minerals ، Wastewater ، Kaolinite ، Commercial Bentonite ،