Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10160720 | Biochemical Engineering Journal | 2005 | 11 Pages |
Abstract
Batch experiments were carried out for the sorption of methylene blue onto mango seed kernel particles. The operating variables studied were initial solution pH, temperature, adsorbent mass, initial dye concentration and contact time. Equilibrium data were fitted to Freundlich and Langmuir isotherm equation and the equilibrium data were found to well represented by Langmuir isotherm equation. The monolayer sorption capacity of mango seed kernel for methylene blue sorption was found to be 142.857Â mg/g at 303Â K. The sorption kinetics was found to follow pseudo first order kinetic model. The methylene blue uptake process was found to be controlled by both surface and pore diffusion with surface diffusion at the earlier stages followed by pore diffusion at later stages. The average effective diffusion coefficient was calculated and found to be 5.66Â ÃÂ 10â4Â cm2/s. Analysis of sorption data using Boyd plot confirms that the external mass transfer as the rate limiting step in the sorption process. Various thermodynamic parameters such as enthalpy of sorption ÎH, free energy change ÎG and entropy ÎS were estimated. The positive value of ÎH and negative values of ÎG shows the sorption process is exothermic and spontaneous. The positive value of entropy ÎS shows the increased randomness at the solid-liquid interface during the sorption of dye ions onto mango seed kernel particles.
Related Topics
Physical Sciences and Engineering
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Bioengineering
Authors
K. Vasanth Kumar, A. Kumaran,