Adsorption of Methyl Red on Coal Fly Ash from Aqueous Solution

Abstract

The discharge of highly colored effluents into natural water bodies is aesthetically displease impedes light penetration, as a result disrupt biological processes within stream and thus treatment is required before discharge into a water body. In the present study, coal fly ash generated from coal based thermal power plant has been used as low-cost and effective adsorbent for the removal of methylene red dye from an aqueous solution. Chemical treatment of coal fly ash was carried out before adsorption with 10% sulfuric acid to improve its surface area. The influence of adsorbent dose, initial dye concentration and contact time at room temperature and pH of 6.8 on removal of the dye has been studied. It was found that, percentage removal of the dye increases by increasing adsorbent dose, initial dye concentration and contact time. The optimum condition of contact time, adsorbent dose and initial dye concentration found were 120 min, 1 g and 25 mg/L respectively. Adsorption data was fitted well on both Langmuir and Freundlich Isotherm models.

Keywords: Methyl red dye, Adsorption, Coal fly ash, Isotherm models