Equilibrium studies of manganese removal from aqueous solution by adsorption on natural zeolite

The adsorption of manganese ions from synthetic aqueous solutions was performed by using natural zeolite (clinoptilolite). In order to determine the manganese uptake at equilibrium a series of experiments were performed under batch conditions from single ion solutions. Experiments were carried out at different initial concentration of manganese ions and at different initial pH values at 20±1̊ C. Increase in initial concentration not only results in an increase in the amount adsorbed (qe) but a decrease in the efficiency of natural zeolite for the removal of Mn from solution. Increases pH value results in an increases the adsorption capacity. The adsorption of manganese ions from diluted solution onto natural zeolite occurs efficiently. The adsorption isotherm of the manganese ions on the adsorbent was determined and correlated with the Langmuir and the Freundlich adsorption isotherm models. The Langmuir isotherm exhibited a better fit for the adsorption data than the Freundlich isotherm. Key words: manganese ions, adsorption, zeolite, equilibriu