Master Thesis on the use of rainwater as drinking water using small-scale water treatment systems
From February 03rd until 24th 2014 Tatjana Wawilow a student from Darmstadt University of Technology, Faculty of Civil and Environmental Engineering, MSc. Environmental Engineering was on a research field trip in central-northern Namibia as part of the research activities of the CuveWaters project. The main question of her research conducted as part of her Master Thesis was to develop and implement a small-scale water treatment plant for drinking water purposes from harvested rainwater.
Currently the harvested rainwater at both pilot locations in Epyeshona and Iipopo cannot be used as a source of drinking water due to microbiological contamination. Two different technologies to improve the quality of drinking water were implemented next to the rainwater harvesting pilot plants in Epyeshona at Emerita Iipinges household and at the Greenhouse office at the rain- floodwater harvesting pilot plant Iipopo. The rainwater from the tanks and ponds were treated using UV radiation from sunlight using an adapted SODIS concept and by the use of two different types of ceramic filter candles.
The farmers from Iipopo and Emerita from Epyeshona were trained in how to use the filter system and how to maintain it. The systems do not need any external energy supply, only the sun in the case of the system using UV radiation and gravity in the case of the ceramic filter system and are very easy to understand. The water quality of the treated water was tested several times in the CuveWaters lab in Outapi. One type of ceramic filter candles tested removed all microbiology from the water and fully met the requirements of the “Namibian Water Act”. Probably due to manufacture problems the microbiological contamination could not be eliminated by the use of the other type of ceramic filter candles. The solar water disinfection proofed to be successful to disinfect as long as the sunrays touch the water for at least 6 hours.