A bioreactor using a tapered fluidized bed was built, characterized and tested. The test consisted of biologically removing phenol from an artificial wastewater in the absence of activated carbon. The data collected during this fermentation were logged on a PDP 11/40 minicomputer. Variables such as oxygen and carbon dioxide percent by volume evolved, the dissolved oxygen concentration, temperature, pH and volumetric air flow rate were monitored. The rate of phenol disappearance was also determined.

This system was then used to study the biological regeneration of activated carbon. The bioregeneration study showed that up to 67% of the activated carbon adsorptive capacity could be recovered. It also proved that the rate of phenol biodegradation was higher in the presence of activated carbon than in its absence.