Synthesis of Zeolite-X from Coal Fly Ash and Its Application in Removal of Methylene Blue Dye

Abstract

Fly ash is an industrial by product which is generated by combustion of coal. During the combustion minerals partially melt to form fly ash particles which is heavy burden on the land because of dumping. The present concern over fly ash is to convert value added products such as zeolite type of materials on proper treatment. Fly ash is having silica, alumina in core and glass phase is on the surface which is more soluble in the alkaline phase to form aluminosilicate gel, so that fly ash having the potential to form zeolite type of material. In the present study, synthesized zeolite X type of material from coal based fly ash. Synthesized zeolite X was characterized by various techniques such as X-ray diffraction (XRD) analyzer, scanning electron microscope (SEM) and BET analysis. Surface area of the zeolite, pore volume, pore radius of the synthesized zeolite was measured and it has been found that synthesized zeolite having mesoporous pores. The synthesized zeolite using as adsorbent in the removal of methylene blue dye from the aqueous solution. The wastewater containing dyes, generated by the textile, printing and papermaking industries, pose major hazard to the environment and the public health. The influences of five dominant parameters of pH, temperature, time, initial dyes concentration, and adsorbent mass on dyes adsorption were investigated for synthesized zeolite X (from fly ash), Commercial zeolite (13X) and Raw fly ash. The percentage of dye removal was mathematically described as a function of experimental parameters and was modeled through central composite design (CCD). According to the predicted experiments, optimum conditions of 10, 32.7°C, 47.87 min, 50 ppm, and 0.25 g, for pH, temperature, time, initial dyes concentration, and adsorbent mass were resulted, respectively for synthesized zeolite X as adsorbent and the maximum dye removal percentage obtained 82. Optimum conditions of 10, 27.08 °C, 54.13 min, 50 ppm, and 0.66 g, for pH, temperature, time, initial dyes concentration, and adsorbent mass were resulted for raw fly ash as adsorbent and the maximum dye removal percentage obtained 42.66. Optimum conditions of 10, 46.96 °C, 32.61 min, 50 ppm, and 0.25 g, for pH, temperature, time, initial dyes concentration, and adsorbent mass were resulted for commercial zeolite (13X) as adsorbent and the maximum dye removal percentage obtained 64.02. Among these three adsorbents, synthesized zeolite gave the maximum percentage of dye removal.