Investigation of dye removal mecanisms of egg shells and their photocatalytic properties

Industrial wastewater from textile dyeing is considered a major environmental problem. For this reason, recycling of wastewater offers environmental and economic values, especially if the materials used originate from the recycling of other types of waste. The eggshell-based dye removal has been studied extensively in a different forms of eggshell for different dyes. This study investigates the dye removal process of eggshells for two different dyes, fuchsine and malachite green, and also the photocatalytic property of egg shell in raw and calcinated forms. Egg shell-derived photocatalysts were characterized by diffuse reclectance UV-Visible and Fourier transform infrared in addition to the electrochemical studies. Electrochemical İmpedance Spectroscopy was used to investigate the impedance and capacitance of raw egg shell and calcinated egg shell in the dark and under 365 nm UV light together with Mott-Schottky analysis. The general dye removal techniques of egg shell derivatives are their adsorption and photocatalytic properties. In this study, we investigated the photocatalytic process of egg shell for two dye molecules. The photocatalytic property of both eggshell forms, raw and calcinated egg shell, has been investigated. Raw and calcinated egg shell did not show a significant photocatalytic effect for Fuchsin dye and Malachite Green. When the same experiment was done for methylene blue, the obvious photocatalytic effect was observed. The color removal of Fuchsin Dye and Malachite Green is mainly due to the pH change of the solution. For both dyes, we observed almost % 100 color removal from the solutions, and this removal process does not depend on the photocatalytic property of the eggshell.