화학공학소재연구정보센터
Chemical Engineering Journal, Vol.163, No.3, 236-242, 2010
Application of film-pore diffusion model for methylene blue adsorption onto plant leaf powders
In the present work kinetics of methylene blue adsorption onto three low-cost adsorbents namely guava leaf powder (GLP), teak leaf powder (TLP) and gulmohar leaf powder (GUL) was predicted using film-pore diffusion model. The model equations were solved numerically by method of lines using Excel. Initial estimates of mass transfer parameters namely external-film transfer coefficient and internal diffusion coefficient were obtained using single resistance models at temperatures 303, 313 and 323 K and for initial dye concentrations 50, 100, 150 and 200 mg dm(-3). Film-pore diffusion model was then used to determine the concentration-independent values of these mass transfer coefficients. Thus, external-film transfer coefficients were found to be in the range of 3 x 10(-6) to 35 x 10(-6) m s(-1), 1 x 10(-6) to 8 x 10(-6) m s(-1) and 1 x 10(-6) to 11 x 10(-6) m s(-1) for guava, teak and gulmohar leaf powders, respectively, in the chosen temperature range. At the same time internal diffusion coefficients were in the range of 0.1 x 10(-12) to 1.9 x 10(-12) m(2) s(-1), 0.1 X 10(-12) to 0.6 x 10(-12) m(2) s(-1) and 0.2 x 10(-12) to 1.3 x 10(-12) m(2) s(-1) for guava, teak and gulmohar leaf powders, respectively. It was evident that film-pore diffusion model could satisfactorily describe kinetics of methylene blue adsorption onto the three low-cost adsorbents used. (C) 2010 Elsevier B.V. All rights reserved.