AWWA ACE90142

A new experimental procedure for conducting adsorption isotherm test is introduced as a result of discovery of molecular oxygen interference with the adsorption process. The presence of molecular oxygen in the test environment induces increased removal of adsorbate from the liquid phase due to polymerization reactions catalyzed by the surface of activated carbon. Since the polymerization of adsorbate on the surface of activated carbon is a slow process, the influence of molecular oxygen on adsorption kinetics becomes apparent only if the kinetic experiment is sufficiently long. Aerobic adsorption parameters (adsorptive capacity, external, and internal mass transfer coefficients) predict working capacity of a GAC adsorber (up to 50% of the full breakthrough) very accurately. The total capacity of a GAC adsorber agrees very well with the aerobic isotherm prediction is the full breakthrough is accomplished.