Equilibrium and kinetic modeling of removal process for heavy metals using activated carbon
Document Type : Review
Abstract
Adsorption process with activated carbon is one of the most common methods for heavy metals removal from various wastewaters. In this study, modeling of of Pb2+,Cd2+,Ni2+ adsorption have been investigated with activated carbon in equilibrium and kinetic states. Langmuir, Freundlich, Redlich-Peterson and Sips isotherms were applied for study of equilibrium in single adsorption systems and multicomponent Langmuir isotherm was selected for equilibrium study in multicomponent adsorption system. All studied isotherms had good prediction for equilibrium of these systems. Pseudo-first order, pseudo second order and film-pore volume diffusion model were applied for investigation of adsorptionkinetics. According to the results, film-pore volume diffusion model based Langmuir isotherm had minimum average relative error. Effective pore volume diffusivity was determined 1.9210-6 cm2.s-1, 1.9010-6 cm2.s-1 and 1.2010-6 cm2.s-1, for Pb2+, Cd2+ and Ni2+, respectively.
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