Yilma Tadesse (PhD)Kalkidan Minwyelet2024-07-312024-07-312022-11https://etd.aau.edu.et/handle/123456789/3335The filwoha hot spring water is used for shower, hydro-therapy massage, sauna bath and steam bath services. Although the natural hot spring water provides such services it is not used as a drinking water. This is as a result of the concentration of parameters such as the total dissolved solid (TDS), the total alkalinity and the fluoride being above the standard requirements for a drinking water. In this research a geothermal still was manufactured and experimental tests were carried out at the Filwoha Spa Service Enterprise, Addis Ababa, Ethiopia. Geothermal still is an apparatus that uses the hot spring water both as a water to be treated and as an energy source that drive the geothermal still operation. The basin area of the geothermal still was and the glass cover tilt angle was fixed at . An L shaped condensate channel of is made to collect the distillate running down the inner surface of the inclined glass cover. To prevent any heat lose, the bottom and sides of the geothermal still was insulated with thick glass wool. The geothermal still construction was contained in a wooden frame of a trapezoidal shape. The geothermal still had an outlet pipe at the front, an inlet pipe at the back and another outlet pipe on the right side for the output discharge with each pipe having a diameter of . The experiment was performed at a water depth of . The operating flow rate for the geothermal still was between . The continues flow of the hot water across the geothermal still serves the purpose of maintaining the temperature of the water stored on the basin. Temperature readings of the parameters such as the basin water and the water vapor were recorded. The geothermal still was estimated to produce 8 liters of distillate output per day. Finally, the water quality analysis reports were prepared by Addis Ababa Water and Sewerage Authority (AAWSA) and Ethiopian Conformity Assessment Enterprise (ECAE) for the distillate samples collected from the geothermal still. The laboratory results showed that the concentration of the total dissolved solid (TDS), the total alkalinity and the fluoride was reduced to the acceptable level for a drinking water.en-USFilwoha hot spring waterGeothermal stillDistillate outputThesis