Fluoride concentrations in groundwater and impact on human health in Siloam Village, Limpopo Province, South Africa

Monitoring of fluoride concentrations in groundwater, identification of sources, and monitoring of the impact of fluoride on human health was undertaken in Siloam Village, Limpopo Province, South Africa. Most of the inhabitants of Siloam Village rely on groundwater for domestic use due to inadequate pipe-borne water supply. A preliminary survey showing that some community members in Siloam Village have mottled teeth motivated the study. Temperature and pH were measured in the field while fluoride and calcium in groundwater were analysed in the laboratory. A survey was conducted to obtain information on the impact of fluoride on human health. 40% of the households and 1 primary school in Siloam Village were interviewed. Fluoride concentrations in groundwater samples were found to be higher than the Department of Water Affairs and World Health Organization recommended values for domestic use of 1 mg/. and 1.5 mg/., respectively. The results of paired two-tailed t-tests showed significant differences between mean values of pH, temperature, calcium and fluoride concentrations for all paired comparisons between 3 sites, with the exception of comparisons between sites GW1 (community borehole) and GW2 (artesian spring). Alkaline pH, low calcium concentrations, high groundwater temperatures and semi-arid climatic conditions of the study area may cause elevated fluoride concentrations in groundwater, by increasing the solubility of fluoride-bearing formations (fluorite). A survey revealed that 87% of the households use groundwater while 85% of these have family members with mottled teeth. 50% of children between the ages of 11 and 14 in Siloam Primary School also have mottled teeth. There is thus evidence suggesting negative human health impacts of high fluoride concentrations in groundwater in Siloam Village. The majority of the community was found to be aware of the fluorides in groundwater and the health impacts thereof making interventions easy to promote

Coagulation efficiency of Dicerocaryum eriocarpum (DE) plant

A study was conducted to investigate coagulation efficiency of the plant Dicerocaryum eriocarpum (DE) in the removal of turbidity from raw water. Widespread poor land use practices contribute to high turbidity in river water, making turbidity management or removal critical, particularly before the water is used for drinking or subjected to chemical treatment. In this study, mucilage from DE was extracted with deionized water and different chloride solutions. A coagulation efficiency of 99% using modified mucilage coagulant was achieved. The modified mucilage of potassium crude extract and sodium crude extract displayed higher coagulation efficiencies than unmodified mucilage of deionized water crude extract. An increase in coagulant dosage and initial turbidity influenced the coagulation efficiency of DE coagulant. A large reduction in turbidity levels of the treated water samples resulted in an improvement in water quality.Keywords: coagulation, Dicerocaryum eriocarpum plant, mucilage, optimise, turbidit

Physico-chemical assessment of borehole water used by schools in Greater Giyani Municipality, Mopani district, South Africa

In the present study, the physical and chemical quality of several borehole water sources, used by rural schools in Greater Giyani Municipality, were assessed to determine their safety for human consumption. Atomic absorption spectroscopy and ion chromatography were used to determine the chemical quality of water sources. The pH of the water samples varied between 5.29 and 8.3 and tended to be lower in summer and higher in winter. The turbidity values varied between 6.17 and 44.7 NTU in some of the schools. High concentrations of magnesium and total hardness were obtained from all water sources. Calcium concentrations were high in some schools. Anions such as chloride and sulphate were within the recommended Department of Water Affairs and Forestry (DWAF) limits except for two sampling points. High concentrations of nitrates were obtained from all schools except in Nyanisi high school. There were no fluorides and phosphates from all schools. Heavy metals like arsenic, iron, cadmium and lead were within the recommended DWAF limits. The results obtained in this study indicate that the water from the studied boreholes is not suitable for human consumption based on hardness and nitrate content and may pose a serious threat to the health of the consumers and therefore calls for urgent intervention in order to reduce such chemicals and preserve the health of the children.Keywords: Physico-chemical water quality, borehole, primary schools, Giyani, South AfricaAfrican Journal of Biotechnology Vol. 12(30), pp. 4858-486

Yield-reliability analysis and operating rules for run-of-river abstractions for typical rural water supply: Siloam Village case study

The study focused on yield-reliability analysis and operating rules for optimum scheduling of run-of-river (ROR) abstractions for typical rural water supply schemes using Siloam Village, Limpopo Province, South Africa, as a case study. Efficient operation of water supply systems requires operating rules as decision support tools. System operation methods have hardly been developed or applied to water supply to rural communities that depend on ROR abstractions. Simulated runoff was used to derive unregulated river yield at different levels of assurance of supply (LAS) for Nzhelele River at Siloam Village using 1-day flow duration curves. Yield-reliability analysis results were used to derive operating rules. The results show that Nzhelele River can meet domestic and low-flow requirements at 50–80% (1:2-1:5) LAS. The low-flow and domestic water requirements can be partially met at 90% (1:10) LAS. The generic operating rules for ROR abstractions were consequently derived from the procedure used in developing operating rules for Nzhelele River. This enables generation of operating rules for ROR abstractions in any typical rural water supply system