Effect of dissolved oxygen on the adsorptive capacity of a granular activated charcoal for phenol and O-Cresol

Abstract

This study is an experimental evaluation of the effect of molecular oxygen on the adsorptive capacity of granular activated carbon (GAC) at bench scale. Adsorption isotherm studies were performed for phenol and o-cresol under room temperature (23) and controlled neutral pH. Standard bottle-point technique was used for three identical sets of bottles with modifications. A new procedure for obtaining the isotherm, denoted as oxic procedure, is introduced where molecular oxygen is purged in one bottle set. The second set, denoted as anoxic, include purging nitrogen gas for excluding the oxygen. The last set does not include any purging and only the standard procedure, aerobic, is used.

Experimental results show that the presence of molecular oxygen increases the adorptive capacity of GAC upto 167% for phenol and 141% for o-cresol. These results were signified statistically using SAS program. It is experimentally proved that the biological activity was not responsible for the increased adsorptive capacity of GAC for phenol and o-cresol. Therefore, a chemical reaction is responsible for this increase.