Equilibrium, Kinetic and Thermodynamic Studies of Malachite Green Dye Removal using Activated Sludge from Common Effluent Treatment Plant

Abstract

Disposal of industrial effluents containing synthetic dyes causes a potential hazard to the land and environment and therefore dyes need to be removed before disposal. In the present study, combined effluent treatment plant (CETP) sludge was activated at 200° C for 1 hour and used as an adsorbent for the removal of malachite green dye from wastewater. The adsorbent was characterized by XRF, SEM, XRD and FTIR. Batch studies were carried out under various experimental conditions by varying contact time, dye concentration, adsorption dose, pH and temperature to assess the potentiality of activated sludge for the removal of malachite green dye from wastewater. The results revealed that the removal of malachite green dye was strongly pH dependent and maximum dye removal was observed at equilibrium pH of 8.0. Optimum adsorbent dose and contact time were found to be 10 g/l and 180 minutes respectively. Thermodynamic studies showed the spontaneous and endothermic nature of the adsorption. Adsorption data have also been correlated with different isotherm models. Hence activated sludge can be used as an effective adsorbent for the removal of malachite green dye from wastewater. It could be considered as good replacement of commercially available adsorbent like zeolites, activated carbon etc. due to its significant low cost and high sorption efficiency.