Remediation of textile industry organic dye waste by photocatalysis using eggshell impregnated ZnO/CuO nanocomposite

Heterogeneous photocatalysis using nanocomposites is of great research interest in the treatment of industrial wastewater. The impregnated photocatalyst was produced by liquid state reaction of ZnO/CuO nanocomposite with extracted eggshells. The structure, functional group, metal composition, bandgap, and photocatalytic activity of the nanocomposites were characterized by using X-ray diffraction, Fourier-transform infrared spectroscopy, atomic absorption spectrometry, and UV-Vis spectroscopy, respectively, in the absence and presence of eggshells. Photocatalytic degradation activities of the nanocomposites under UV light irradiation have been tested for a real sewage sample taken from Debre Berhan Textile Industry. From the results, the optimized degradation efficiency of the dye was 97.95% with 0.4 g dose of the photocatalyst, 120 min irradiation time, 120 °C temperature, and pH of 6.7. The results revealed that eggshell impregnated nanocomposite had better catalytic activity than the naked nanocomposite. This is due to the highly porous structure of eggshell biomasses and their sorption characteristics. In conclusion, when nanocomposites are supported by eggshell biomasses, they are excellent photocatalysts and can minimize the contamination of organic dyes from textile effluents.