Application of film-pore diffusion model for methylene blue adsorption onto plant leaf powders

作者：Ponnusami V^*; Rajan K S; Srivastava S N

来源：Chemical Engineering Journal, 2010, 163(3): 236-242.

DOI：10.1016/j.cej.2010.07.052

• Methylene blue
• Adsorption kinetics
• Film-pore diffusion model
• Low-cost adsorbents

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.

• 出版日期2010-10-1