Treatment of garage wastewater using activated carbon made from khat (Catha edulis) and neem (Azadirachta indica) leaves

Abstract

This paper compares the effectiveness of activated carbon prepared by khat and neem leaves in treating the wastewater collected from automobile service stations. Wastewater was collected from service stations in the Haramaya city of Ethiopia. Proximate analysis of different leaves, such as khat, neem and gudhal, was tested, and the fixed carbon percentage is 81, 78 and 72, respectively. On the basis of high percentage of fixed carbon, khat and neem activated carbon are selected for further study. Zinc chloride is used for activation, and the samples khat and neem activated carbon are characterized by X-ray diffraction, scanning electron microscopy, thermo-gravimetric analysis and Fourier transform infrared spectroscopy. The turbidity and pH of wastewater was tested before and after the treatment. In the case of khat activated carbon, turbidity was reduced up to 30 mg/lit and the combination of khat and neem activated carbon removed up to 15 mg/lit. In both the cases, khat activated carbon is effective in neutralizing pH and reducing turbidity.