Geochemistry and water quality assessment of central Main Ethiopian Rift natural waters with emphasis on source and occurrence of fluoride and arsenic

Water defluoridation by bauxite-gypsum magnesite (B-G-Mc) based filters calcined at 350 500C

“…Fluoride has been identified as a cause of dental and skeletal fluorosis world over (Maliyekkal et al, 2010;Rango et al, 2010;Peter, 2009;Onyango et al, 2009). The World Health Organisation (WHO) set a guideline value of 1.5 mg/L as an acceptable upper limit (WHO, 2006).…”

The effect of non-fluoride factors on risk of dental fluorosis: Evidence from rural populations of the Main Ethiopian Rift

“…The study was performed in 20 rural communities located in the Ziway-Shala lake basin of the Main Ethiopian Rift (MER) region. Across this zone, large rural populations are chronically exposed to a range of naturally-occurring contaminants in groundwater (Gizaw, 1996;Kilham and Hecky, 1973;Rango et al, 2009Rango et al, , 2010aRango et al, , 2010bReimann et al, 2003), which is one of the main sources for drinking and cooking water.…”

Experimental Evaluation of Activated Termite Mound for Fluoride Adsorption

“…Fortunately, carbonate and phosphate ions are absent or very little in most groundwater sources of the Main Ethiopian Rift [3,4]. The results also revealed that the adsorption of fluoride was greatly affected in the presence of the mixture of the anions in the solution in the concentration range of 100 to 500 mg/L, indicating that the effect of PO 4 3-and CO 3 2-ions overshadowed the influence of the presence of the other anions. The presence of HCO 3 -ion in the concentration range of 100 to 500 mg/L slightly decreased the adsorption efficiency.…”

“…9. The result showed that the adsorption efficiency was significantly decreased in the presence of PO 4 3-and CO 3 2-ions in the solution at a higher concentration range of 100 to 500 mg/L. This presumably attributed to the high affinity and capacity of TTM for PO 4 3-and CO 3 2-ions [18].…”