Removal of etyhl orange dye using waste eggshell

Abstract

In this study, waste eggshells were used as a low cost raw material to remove ethyl orange dye in aqueous solution. The waste eggshells were calcined at temperatures of 600, 700, 800 and 900°C in the furnace for 2 h. Further, the calcined waste eggshells were treated chemically using 2 M of potassium carbonate. The calcined waste eggshells were characterized using Thermal Gravimetric Analyzer (TGA). The surface morphology of the calcined and uncalcined (i.e. natural) waste eggshell was obtained using Scanning electron microscope (SEM). The dye concentration was determined using UV-Vis spectrometry at wavelength of 474 nm. The results obtained showed that the percentage of dye removal using natural waste eggshell was 47.1%. For the calcined waste eggshell, the removal of dye decreased as the calcined temperature increased. For the pH effect, the acidic solutions give the highest percentage of dye removal which is 54 %. As expected, the higher the dose of waste eggshell used, the higher the dye removed. The highest removal of dye was obtained by using 2.0g of waste eggshell which is 48.2%. For the temperature effect, the adsorption of dye decreased as the temperature increased. The highest removal of dye was achieved at 50°C which is 63.0%. In this study, the adsorption process was found to fit the Freundlich isotherm than of the Langmuir isotherm. © 2013 Penerbit UTM Press. All rights reserved.