Removal Of Noxious Fluoride Ion From Wastewater Using Granular Activated Carbon (Gac): Kinetics And Absorption Studies

Abstract

Concentration of a Fluoride over a permissible limit is now a worldwide problem and often referred to as 21st century calamity. Almost 372 million people of around 24 countries including Australia, Brazil, Canada, Chile, Ireland, Malaysia, the U.S., and Vietnam are affected by high concentration of Fluoride .The removal of Fluoride from industrial waste water by granular activated carbon(GAC) has been found to be dependent on concentration, pH, contact time, adsorbent dose and temperature .Langmuir and Freundlich isotherm models were used to determine the adsorption parameters. The adsorptive power of fluoride ions on granular activated carbon satisfies not only the Langmuir assumptions but also the Freundlich assumptions i.e. multilayer formation on the surface of the adsorbent with an exponential distribution of site energy. The optimum pH, adsorbent dose, initial concentration and contact time were found to be 4,32g/l, 20mg/l, 120 min respectively.