Comparison of the defluoridation capacity of zeolites from Ethiopia and Mexico

Fluorosis, either dental or skeleton, is often due to the high fluoride content of well waters. In this work, using solutions which contain different amounts of fluoride, natural zeolites from Ethiopia and Mexico were tested. It is shown that, although zeolites are known to be cationic exchangers, their extra-framework aluminum and their high calcium contents determine their performance. A mechanism involving adsorption and ion exchange is proposed. KEY WORDS : Ion exchange, Purification, Fluorosis, Clinoptilolite, Stilbite, Heulandite, Analcime Bull. Chem. Soc. Ethiop. 2015 , 29(1), 53-62 DOI: http://dx.doi.org/10.4314/bcse.v29i1.5