Preliminary Investigation of an Inexpensive Method to Remove Fluoride in Rural Water: A Case Study of Luwini Spring, Limpopo Province, South Africa
43 Pages Posted: 20 Oct 2013
Date Written: October 17, 2006
South Africa has scarce surface water and consequently groundwater is the only other means of meeting drinking water demand. It is estimated that approximately 15 million people in South Africa rely on groundwater for domestic purposes. However, groundwater often has some undesired solutes. The concentration of fluoride in drinking water is of concern because excessive fluoride can result in dental decay to users. This was the case in the majority of villagers using groundwater at Dididi village in the Thulamela Municipality in the Limpopo Province of South Africa. The assessment of groundwater quality is therefore of critical importance in order to determine the fitness of water for domestic use. Groundwater samples were taken from Luwini spring in Dididi village, Limpopo Province. Sample results showed a mean fluoride concentration of 4.6 mg/l, which is significantly higher than the fluoride level of 0.75 mg/l recommended in South Africa and the 1.5 mg/l recommended by WHO for domestic water use.
Defluoridation was attempted using wood ash, which is a naturally produced material following wood burning. pH adjusted and pH unadjusted experiments were undertaken to assess the effects of pH in defluoridation. The adjusted pH was 5.38, while the unadjusted pH was measured at 9.37.
The experimental results showed a relative effect of adjusted pH versus unadjusted pH during fluoride removal. The wood ash treatment resulted in a significant drop in fluoride levels from 4.6 mg/l to 0.3 mg/l, which is well within acceptable standards. This shows that wood ash materials are capable of fluoride removal and further studies need to be done to assess the potential of other natural, viable and cost effective materials that can also be used in defluoridation.
Keywords: Groundwater, Fluoride, Wood ash, Defluoridation, Fluorosis
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