Title: Correlation between firing temperature and defluoridation capacity of brick clay

Authors: Chamara Seneviratne, Namal Priyantha

Addresses: Department of Chemistry, University of Peradeniya, Peradeniya, Sri Lanka. ' Department of Chemistry, University of Peradeniya, Peradeniya, Sri Lanka

Abstract: The amount of fluoride ions adsorbed on laboratory fired brick clay varies with the initial concentration according to Type I adsorption isotherm for firing temperatures up to 700 °C, forming inner-sphere complexes between fluoride and mineral surfaces of brick clay. Type II isotherm is valid above this firing temperature forming outer sphere complexes. The turbidity of suspensions of low fluoride concentrations is negligible with brick clay fired at 300°C to 600°C. Moreover, the removal of fluoride by brick clay fired at intermediate temperatures is high followed by a decrease at high firing temperatures.

Keywords: defluoridation; brick clay firing; pollution prevention; turbidity; fluoride–brick particle interaction; bulk properties; surface properties; Langmuir adsorption isotherm; Freundlich adsorption isotherm; fluoride ions.

DOI: 10.1504/IJGENVI.2009.026945

International Journal of Global Environmental Issues, 2009 Vol.9 No.3, pp.239 - 248

Published online: 09 Jul 2009 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article