Use of Zircon in the Physicochemical Process of Defluorination of Hyperfluorinated Brackish Water from the Diouroup Borehole (Senegal)

Abstract

In phosphate-producing countries (United States, Commonwealth of Independent States, North and West Africa including Senegal), the presence of phosphate ores (hydroxyapatite) is often associated with that of fluorine ores (fluoro apatite). In these regions, water from confined aquifers may have excessive fluoride contents. While the potability standards in tropical climates are 0.7 mg/L at a temperature of 25°C In the central zone of Senegal, hyperfluorinated brackish water constitutes a public health problem. It is in this context that it was decided to make our contribution to the purification of drinking water in this area. In our study, we used as an element in the physicochemical defluorination process. The results obtained, by this physicochemical treatment by filtration on the zircon column, showed overall a reduction in fluoride contents of 67.55% (i.e. from 6.41 mg/L to 2.08 mg/L) in chlorides of 10.44%. We can therefore affirm that zircon can be used for the defluorination of hyperfluorinated brackish waters. However, these results can be improved by lowering the pH of the water before treatment and increasing the retention time.