EQUILIBRIUM, KINETIC AND THERMODYNAMIC STUDIES ON ADSORPTION OF REACTIVE BLACK 5 DYE BY LACCASE MODIFIED-RED MUD FROM AQUEOUS SOLUTIONS

Due to increasing industrial activities, textile dyes lead to contamination of the water as organic pollutants. These dyes are considered to be pollutants due to their high color density, and they are toxic at even low concentrations. The presence of textile dyes in the environment is one of the major concerns because of their toxicity and threat to human life. Thus, the removal of dyes from colored wastewater, particularly from textile industries, is one of the major environmental concerns. Various techniques have been employed in the past for the removal of dyes from wastewater. Most of these conventional treatment techniques are rather expensive. But adsorption process has been found to be a more effective method for treating dye-containing wastewater. In this study, removing of Reactive Black 5 from aqueous solutions has been studied using red mud waste material after its modification with laccase from Lactarius volemus. Batch adsorption experiments have been performed as a function of pH, contact time, temperature and adsorbent dose. The results show that laccase modified-red mud has a high level of adsorption capacity. The adsorption isotherm studies reveal that Langmuir and Freundlich relations can predict good equilibrium diagrams under isotherm conditions. Consequently, it is concluded that the laccase modified-red mud can be successfully used for the removal of Reactive Black 5 from aqueous solutions.