Removal of health hazards causing acidic dyes from aqueous solutions by the process of adsorption

The association of dyes, particularly acidic dyes with health related problems is not a new phenomenon. A lot of well established literature is already available on the role of dyes as a major cause in skin and respiratory diseases. The adsorbents which are of low cost, locally available and are relatively new for their acidic dyes removal capacity from aqueous solutions were investigated. Bagasse, cow dung, groundnut shells, pea shells, used tea leaves, wheat straw were used in their charcoal form whereas brick kiln ash and cement kiln ash adsorbents were used as such for the removal of acid violet 17, acid violet 49, acid violet 54, acid blue 15 and acid red 119. The effects of various experimental parameters, initial pH, dye concentration, sorbent dosage, ion strength, contact time were examined and optimal experimental conditions were decided. At initial basic pH more than 8.0, all the five dyes studied could be removed effectively. The isothermal data for adsorption followed the Freundlich and Langmuir models. The adsorption results in this study indicated that all the adsorbents were attractive candidates for removing acidic dyes from dye wastewater.