Assessment Of Selected Borehole Water Quality And Efficiency Of Homemade Water Filter Purification Devices In Mariental Rural, Hardap Region.

ABSTRACT

Approximately 6.6% of Hardap Region has unsafe drinking water according to WHO (2018) guidelines. Consuming this water can cause serious illness. Three filters, namely the bucket filter, sand filter, and charcoal filters were constructed and tested for physico-chemical and bacteriological removal efficiencies. More than 500 000 people in developing countries use filters to treat drinking water. Regardless of this positive implementation, there is limited knowledge to improve its design and operation. This study reports that the filters were efficient in removing carbonate hardness, total coliforms, and E. coli. When statistically tested, the filters showed more or less the same removal capacity, only differing from the carbonate hardness and total coliforms content. The serial dilution tests that were conducted showed that the filters were effective at removal of total coliforms and E. coli at an average of 84.2% and 96.2% for the bucket filter, 91.9% and 99.6% for the sand filter and 74.9% and 98.1% for the charcoal filter respectively. However, complete removal of total coliforms and E. coli was not achieved. It was also reported that there was no relationship between the flow rates and the removal efficiencies. The charcoal filter had the highest removal efficiency of carbonate hardness but did not meet the daily flow rate requirement, therefore it would not be recommended. The sand filter had the highest total coliform and E. coli removal efficiency and it met the daily flow rate requirements, so it would be recommended, but alternative disinfection should be followed. This study recommends that filters be adjusted with smaller holes on the diffuser plates, increased filtrate depth and using granular activated charcoal. Filters should also be used with a disinfection process like boiling or chlorination.