Author/Authors :
Dessie، Awrajaw نويسنده 1Department of Public Health, College of Health Science, Mekelle University, Mekelle, Ethiopia , , Alemayehu، Esayas نويسنده Department of Environmental Health Science and Technology, College of Public Health and Medical Sciences, Jimma University, Jimma, Ethiopia , , Mekonen، Seblework نويسنده Department of Environmental Health Science and Technology, College of Public Health and Medical Sciences, Jimma University, Jimma, Ethiopia , , Legesse، Worku نويسنده TREE Foundation, Texas, USA , , Kloos، Helmut نويسنده Department of Epidemiology and Biostatistics, University of California, San Francisco, California, USA , , Ambelu، Argaw نويسنده Department of Environmental Health Science and Technology, College of Public Health and Medical Sciences, Jimma University, Jimma, Ethiopia ,
Abstract :
Disinfection of contaminated water using solar radiation (SODIS) is known to inactivate bacteria. Its inactivation
efficiency depends on local conditions where the disinfection is made. This study was aiming to test the efficiency
of solar disinfection using different water parameters as low-cost household water treatment technology.
Inactivation of microbes was tested using fecal coliform as test organism. The SODIS experiment was carried out at
turbidity 2NTU, pH 7, and various water temperature (38.1°C, 41.8°C, 45.6°Cand 51.1°C) and solar intensities, using
clear and black plastic bottles filled to different depths. The results show that the rate of microbial inactivation in
relation to depth of water, turbidity, container type, intensity of light and color of container was statistically
significant (p < 0.05). However, bottle placement, exposure and water pH were unrelated to microbial inactivation.
Bacterial re-growth was not observed after solar disinfection. By adjusting the parameters, complete and irreversible
fecal coliform inactivation was achieved within an exposure time of less than four hours in the areas where the
solar irradiance is about 3.99 kW/m2 and above. Our results indicate that application of SODIS could play a
significant role in the provision of safe water in rural communities of developing countries where there is ample
sunshine, specifically in sub-Saharan African countries.
