Removal of Dyes from Aqueous Solution using low cost Activated Carbons derived from Moringa Oleifera fruit shell waste

The purpose of this study is to suggest an efficient process, which does not require a big investment for the removal of dye from waste water. Activated carbon developed from agricultural waste material were characterized and utilized for the removal of dye from water. Systematic studies on dyes adsorption equilibrium and kinetics by low cost activated carbons were carried out. Adsorption studies were carried out at different temperatures, particle size, pH and adsorbent doses. Both Langmuir and Freundlich models fitted the adsorption data quite reasonably. The results indicate that the Langmuir adsorption isotherm model fits the data better as compared to the Freundlich adsorption isotherm model. Plausible mechanism was established for dye adsorption on developed adsorbent. Further, the data are better correlated with linear regression form of each model. The kinetics studies were conducted to delineate the effect of temperature, initial adsorbate concentration and particle size of the adsorbent. The adsorption of dye follows the pseudo second order rate kinetics. On the basis of these studies, various parameters such as effective diffusion coefficient, activation energy and entropy of activation were evaluated to establish the mechanisms. It is concluded that the adsorption occurs through a particle diffusion mechanism at temperature 30 to 60 °C.