ABSTRACT
A decade ago biodegradation was measured at a worst-case level by substrate disappearance. Many reports in the area of environmental microbiology and wastewater engineering documenting biodegradation were accompanied by gas chromatographic analysis showing the net loss over time of a parent compound. In some cases, even visual disappearance of insoluble crystalline organics, such as naphthalene, was used as a gross measure of biodegradation. Most often, abiotic or sterile control samples were used in such assays of biodegradation. However, little insight was developed into nonmetabolic interactions among organisms and pollutant substrates and the measured biodegradation. In the area of wastewater treatment, BOD or COD removal measured by comparing influent and effluent concentrations was used as a measure of pollutant biodegradation, with the assumption that recalcitrant organics had essentially the same fate as labile organics in wastewater treatment.
