A Kinetic Study on the Adsorption of Chromium(VI) onto a Natural Material Used as Landfill Liner   Hai-jun Lu Institute of Poromechanics, Wuhan Polytechnic University, Wuhan, 430023, China; Institute of Geotechnical Engineering, Dalian University of Technology, Dalian, 116024, China e-mail: luhaijun111@163.com Mao-tian Luan Institute of Geotechnical Engineering, School of Civil and Hydraulic Engineering, Dalian University of Technology, Dalian, China Jin-li Zhang Institute of Geotechnical Engineering, School of Civil and Hydraulic Engineering, Dalian University of Technology, Dalian, China
			ABSTRACT

The chromium(VI) sorption to the natural clay used as liner-soil material of solid waste landfill was investigated by batch tests. The influence of physico-chemical key parameters such as the initial concentration and the temperature of solution, has been considered in batch tests. In order to understand the adsorption mechanism, the kinetic parameters of adsorption of chromium(VI) onto the natural clay were determined. The pseudo-second order kinetic model is the best choice among all the kinetic models to describe the adsorption of chromium(VI) onto the natural clay. The activation energy (Ea) value for chromium(VI) was found to be 22.7 kJ/mol according to the slop from the plot of lnk₂ against 1/T. The value of activation energy (Ea) suggests that the rise of the solution temperature favors adsorption of chromium(VI) onto the clay, and the adsorption process might be a by chemical adsorption. The thermodynamic parameters indicate that the adsorption of chromium(VI) onto the natural clay is endothermic reaction in nature.

Keywords: Adsorption; Kinetics; Thermodynamic Parameters; Landfill

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