African Journal of Biotechnology Vol. 6 (22), pp. 2541-2549, 19 November 2007   

ISSN 1684–5315 © 2007 Academic Journals        

Full Length Research Paper

Determination of levels of fluoride and trace metal ions in drinking waters and remedial measures to purify water

Mahejabeen Mukhtar* and Hajira Tahir

Department of Chemistry, University of Karachi, Pakistan.

*Corresponding author. E-mail: prime1@super.net.pk.

Accepted 16 October, 2007

Fluoride is recognized to be most effective caries-preventive agent. The main source of fluoride for people is generally food and drinking water. For this reason, fluoride and other metal ion concentrations in the drinking water samples were estimated. For the determination of fluoride, Na, Li and K an ion – meter and flame photometer were used. While the concentrations of other metal ions (Mn, Cd, Co, Ni, Pb, Fe, Zn and Cu) were estimated by flame atomic absorption spectrophotometer. Statistical parameters and multiple correlations between paired water samples were also calculated. For the purification of water, adsorption technique was adopted using Al₂O₃ and Al₂O₃ -Pb _0.1, Al₂O₃ – Pb _{0. 01} doping systems. Adsorption isotherm equations were also applied to calculate the values of respective constants. Thermodynamic parameters (DG^o, DH^o and DS^o) were also calculated. According to the results obtained, the metal ion concentration in the drinking waters in the studied area are within the safe drinking water regulation limits and also the fluoride level is lower then the permissible limit for flouride.

Key words: Water samples, statistical analysis, purification of water samples, adsorption, Na metal, alumina, doping system.