Adsorption of safranin from wastewater using coal fly ash

摘要: The discharge of highly colored effluents into natural water bodies not only is aesthetically displeasing, but also impedes light penetration, thus upsetting biological processes within stream and thus required treatment before discharge into a water body. In the present study, fly ash generated from coal based thermal powers station had been converted into a low-cost adsorbent and characterized for by SEM, EDEX, XRD and FTIR. It was used as low cost adsorbent for the removal of Safranin dye from wastewater of textile industry. Batch studies were carried out to study the effect of pH, adsorbent doses, adsorbate concentration, temperature and contact time. The results of batch studies revealed that the adsorption of Safranin was strongly pH dependent and maximum Safranin removal was observed at equilibrium pH of 9. Optimum adsorbent dose and contact time were found to be 20 g/l and 120 minutes respectively. Kinetic studies have been were performed to have an idea of the mechanistic aspects and to obtain the thermodynamic parameters of the process. The results also show that adsorption decreases with increase in temperature thereby showing the process exothermic in nature. Adsorption data have also been correlated with both Langmuir and Freundlich isotherm models.