A comparative study of Cu(П) and Pb(П)adsorption by Iranian bentonite (Birjand area) in aqueous solutions

Abstract One of the hazardous pollutants which lead to sever toxic effect in living organism and ecological problems is heavy metals such as Cu(II) and Pb(II). Cu(II) and Pb(II) removal by Iranian bentonite experiment were conducted in single component and multi component systems. The bentonite from Birjand area was characterized by X-ray diffraction and FTIR spectroscopy. The effect of initial Cu(П) and Pb(П) concentration have been investigated on adsorption process. The equilibrium study was performed and followed by five different isotherm models which include two parameters (Langmuir, Frendlich, Temkin and D-R) and three parameters (Khan) models. From the Langmuir isotherm, the equilibrium adsorption capacity for Cu(П) is 21.10 to 22.17 mg/g and that for Pb(П) is 27.80 to 40.49 mg/g in single component and multi component systems. Comparative adsorption of Cu(II) and Pb(II) onto bentonite showed that the affinity for Pb(II) to interact with bentonite is higher than that of Cu(II). Base on free energy of adsorption value for Cu(П) and Pb(П), interaction between these ions and Iranian bentonite is chemical adsorption, that is to say, ion exchange.

Keywords:

Cu(II) and Pb(II) removal , Comparative adsorption , Isotherm models