Kinetic and Isotherm Studies of Congo Red Adsorption from Aqueous Solution by Biowaste Material

Abstract

Toxicity caused by the presence of synthetic dyes in aquatic system is extremely important from the environmental point of view because most of these dyes are toxic, carcinogenic and mutagenic. In the present work the ability to remove 'Congo red' from aqueous solution has been studied by using waste material Pigeon dropping, as an adsorbent. Effects of various parameters on adsorption process such as; contact time, adsorbent dose, initial dye concentrations, pH and temperature was studied. The isotherm data was described by the Langmuir and Freundlich adsorption isotherms. The kinetic data were used for modelling from the second-order kinetic models and intra-particle diffusion model. The thermodynamic studies showed that the process is exothermic and physiosorption. The present investigation confirms that Pigeon dropping can be successfully employed as a good adsorbent for the removal of dye from effluent.