Design and development of domestic slow sand water purification system :

Abstract

Uganda as a country is considered to be well endowed with natural water resources, with about 43,942km covered with wetlands and 16% of the total area covered with open water sources. This surface water resources act as major sources of water to communities without access to borehole, protected well and piped water especially village communities and peri urban communities, but these resources are continuously continued to be polluted by human activities and discharge of waste to them, this makes the water unsafe for consumption without any form at-treatment and as a result persistent of waterborne diseases. Kabrari landing site case study area of this project is an example of the communities who depend on surface water from Lake Kyoga and streams. Therefore, the main objective of the study was to design and develop a domestic slow sand water purification system which would therefore provide access to safe and clean water at house hold level having average number of 6 people, reducing the prevalence of water borne diseases. The quantification of contaminants from Lake Kyoga, stream and nearby pond water was done by laboratory testing where by the water was found not to be safe for consumption without treatment. The major filter components were then designed and developed and others selected. The filter components were then assembled and its performance tested on the bacterial account removal, turbidity; TDS, pH, Nitrates and EC by taking filtered water to the laboratory for tests. The filter was able to reduce E-coli and T-coli to significant level though not to standards with 80.8% and 77% removal respectively. The physical and chemical parameters were reduced to the UNWQ standards with a filter being very much effective on turbidity removal by 92.6%. The filter was able to purify 9litres of water per hour. providing 216 litres of water per day for 6 people in a house hold.