Removal of copper, nickel, cobalt and manganese from aqueous solution by kaolinite

The removal of some heavy metals such as Mn(II), Co(II), Ni(II), and Cu(II) from aqueous solution is studied using a raw kaolinite. The sorption of these metals on kaolinite conformed to linear form of Langmuir adsorption equation. Langmuir C-m constants for each metal were found as 0.446 mg/g (Mn), 0.919 mg/g (Co), 1.669 mg/g (Ni), 10,787 mg/g (Cu) at 25degreesC, respectively. Also, kinetic and thermodynamic parameters such as enthalpy (DeltaH), free energy (DeltaG) and entropy (DeltaS) were calculated and these values show that adsorption of heavy metal on kaolinite was an endothermic process and the process of adsorption was favoured at high temperatures. (C) 2002 Elsevier Science Ltd. All rights reserved.