Adsorption of heavy metal ions in water on kuluncak (Malatya) vermiculite

Investigation for cheap sorbents led to using clay minerals in the removal of heavy metal ions in water. In this study, adsorption mechanism of Zn2+, Pb2+ and Cr3+ ions on Kuluncak (Malatya) vermiculites was investigated. In this regard, the adsorption mechanism was evaluated under various conditions in batch adsorption tests to determine the optimum process parameters. The resultant data were fitted to common adsorption models.The effect of adsorbent dosage, stirring time, initial metal ion concentration, pH etc on Zn2+, Pb2+, and Cr3+ ions removal was determined. Additionally, metal hydroxylformation and its effect on adsorption and removal were evaluated. It was found that the heavy metal ion removal by vermiculite mineral can be represented well by Langmuir adsorption isotherm.The optimum parameters in 100 mL of total solution was determined to be as 1 g adsorbent, 2 hours of stirring time and pH 7.0 for Zn2+, and pH 5.5 for both Pb2+ and Cr3+ ions. The maximum adsorption capacity for vermiculite under the mentioned conditions was determined as 15.32 mg/g, 29.59 mg/g and 27.70 mg/g for Zn2+, Pb2+ and Cr3+ ions, respectively.Finally, It was concluded that, when optimum conditions ensured, Kuluncak vermiculites can be comparable a good adsorbent and can be used in practical applications of heavy metal ion removal.