Kumie, Abera(PhD)Kaba, Mirgissa(PhD)Mekonnen, Tamrat2018-07-112023-11-052018-07-112023-11-052015-09http://etd.aau.edu.et/handle/123456789/8046Background: Among all liquids, water is a unique substance and one of the most important natural resources. In the absence of safe and adequate drinking water supplies, diseases such as diarrhea, skin and eye infections are common. Treatment methods were thus required in order to protect the health of consumers. Currently seed of tropical plant Moringa Olifeira is being recommended as cost effective technology for water treatment in developing countries. The pH at which coagulation occurs is the most important parameter for proper coagulation performance as it affects the surface charge of colloids. Objective: The present study was carried out to determine effect of water pH on turbidity removal and bacterial load reduction using Moringa Olifeira for water treatment. Methods: During this study, ground water from open well and tap water were collected for treatment by Moringa Olifeira seeds in powdered form. Primarily the minimum dose of Moringa Olifeira for effective treatment was identified. Then coagulation ability of Moringa Olifeira seed extract was assessed at different pH values (4, 5, 6, 7, 8, and 9) of water. Parameters which may influence coagulation effectiveness of Moringa Olifeira were kept under control during experimental procedure. Result: The result showed that 60mg of Moringa Olifeira is the optimum dose to treat water with 167NTU initial turbidity and 310 total coliforms. The effect of water PH on total coliforms reduction and turbidity removal effectiveness of Moringa Olifeira was studied and its removal effectiveness is also found to be 90.32% and 90.34% respectively. The pH evaluated has statistically significant effects on the turbidity removal and total coliform reduction with the p-values much lower than 0.05(1.2*10-11). Conclusion: Effectiveness of Moringa Olifeira in reducing turbidity and bacterial load is significantly affected by water pH values. Therefore effect that could arise from variation in the pH of water should be considered. Sequentially, since Moringa Olifeira does not guarantee impurity removal as World Health Organization guidelines, additional disinfection of coagulated water to remove pathogens is necessary in order to achieve standard quality before the water is drunkenBacterial load reduction using Moringa Olifeira for water treatmentThesis