The Effect of Bottle Scratches and Lime Juice on Natural Solar Radiation Disinfection (SODIS) Techniques on Different Bacterial Colonies at ShoaRobit and Surrounding Rural Kebeles

Over one billion people on Earth do not have access to clean drinking water. Several nonprofit and government organizations are promoting low cost, household methods for water purification [1, 2]. One of best alternative approach for equator and temperate region including Ethiopia is solar water disinfection or SODIS. The previous work done at Shoarobit and Surrounding Rural Kebeles, shows that SODIS treatment with clear 1.5 bottles and low turbidity, disinfection is efficient at the end of six hours [3]. However frequently use of the same bottle cause for scratch on the surface of the bottle. Hence this paper addresses effect of bottle scratch and lemon juice (as a catalyst) on solar disinfection. Different level of scratches, Less scratch bottle (LSB), Slightly Scratch Bottle (SSB) and Highly Scratch Bottle (HSB) was analyzed. Since SODIS treatment is mainly due to UV radiation, causes for lysis the DNA of microorganisms, if it is not passes through the surface of the bottle the method became inefficient. From the result it was obtained that there is significance statistical difference between densities of scratched bottles. The disinfection efficiency different scratch bottle is decreases as the following order LSB > SSB > HSB. In addition it was tested that effect of lemon juice on solar disinfection. The pH decrease (acidity increase) and solar disinfection has a synergic effect. This was shown the disinfection efficiency increase accordingly the following pH order: pH = 3 > pH = 5 > pH = 7. In conclusion at the end of six hours almost all bacterial colonies was disinfected in all forms of scratching bottles and this disinfection efficiency of the method enhance with adding lemon juice.