International Journal of Environmental Sciences

Volume 4 Issue 3 2013- November 2013    Pages: 250-258  <<Previous    Next>>

Freundlich, Langmuir adsorption isotherms and kinetics for the removal of malachite green from aqueous solutions using agricultural waste rice straw

Author Information:

Jagdish Singh, Gagndeep Kaur

Department of Biotechnology, Mata Gujri College Fatehgarh Sahib Punjab, India


Malachite (N-methylated diamino triphenyl methane), a green menace, is extensively being used as dye for colouring silk, leather and paper. It is carcinogenic and catalyzes allergic problems. In this work agricultural waste rice straw as adsorbent was employed to remove Malachite green from aqueous solutions. Effects of pH, concentration of the dye, temperature and adsorbent dosage was determined for maximum removal of dye. Equilibrium isotherms for the adsorption of the dye were well fitted to the Freundlich and the Langmuir isotherm models. Thermodynamic parameters, Gibb’s free energy (∆G◦), change in enthalpy (∆H◦) and change in entropy (∆S◦) have revealed spontaneous and endothermic nature of adsorption process. Kinetic measurements established that the adsorption of Malachite green over rice straw follows first-order kinetics

Keywords: Adsorption, Malachite green, Isotherm, Kinetics, Dye


© 2013 Copyright by the authors, licensee Integrated Publishing Association.This is an open access article distributed under the Creative Commons Attribution License (3.0) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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