Adsorption of Ni (II) Ions from aqueous solutions by kaolinite

Heavy metal ions have very serious harmful effects on human health, living creatures and ecological system. Heavy metal ions from water sources and waste water should be removed and reduced to allowable levels. Several methods are used to remove heavy metal ions from aqueous solutions. Among these methods, adsorption is one of the most common and widely used methods. In this study, the adsorption of Ni (II) heavy metal ion from aqueous solutions was aimed by using kaolin as a low-cost alternative adsorbent source. The effects of parameters such as the amount of adsorbent, the concentration of initial Ni(II) ions, temperature, the initial pH of the solutions and contact time the effect of on adsorption were investigated. It has been determined that the adsorption efficiency decreases with increasing initial Ni (II) ion depending on the duration of the contact, the adsorption efficiency increases with increasing pH value and the adsorption capacity of kaolin decreases with increasing temperature. The efficiency of adsorption increased with increasing the adsorbent dosage. The isotherm and kinetic studies relating to this adsorption process show that the equilibrium data follow the Langmuir isotherm while the process kinetic obeys by the pseudo-second order kinetic model