REMOVAL OF HEXAVALENT CHROMIUM BY ADSORPTION ONTO FIRECLAY AND IMPREGNATED FIRECLAY

Abstract

The removal of hexavalent chromium from its aqueous solutions by adsorption onto fireclay (FC) and impregnated fireclay (IFC) has been studied at 30°C. The adsorption process follows the Langmuir-type adsorption behavior, and the extent of adsorption is more for impregnated fireclay. It is found that electrostatic and H-bonding interactions play a key role in binding the adsorbate molecules to the adsorbent surface. The adsorption process is affected greatly by variation in pH and temperature of the system. Low pH and high temperature favor the adsorption process.

Various kinetic and adsorption parameters such as rate constant for adsorption, intraparticle diffusion rate constant, diffusion coefficient, and adsorption capacity have been evaluated to reflect the experimental findings.

Keywords:

• Adsorption
• Fireclay
• Impregnated fireclay
• Hexavalent chromium

Acknowledgments