KINETICS AND PRACTICAL SIGNIFICANCE OF BIODEGRADATION OF LINEAR ALKYLBENZENE SULFONATE IN THE ENVIRONMENT

This paper reviews the kinetics of biodegradation of linear alkylbenzene sulfonate (LAS) in engineered (wastewater treatment) and natural environment systems, focusing on work conducted in our environmental laboratories over the past 10-15 yr. Biodegradation studies were conducted in laboratory microcosms in which pure-chainlength [C-14]-ring-labeled LAS homologs were used to allow complete mineralization to be assessed. In general, biodegradation rates for a series of LAS homologs (C10-C14) were comparable to each other and to values for naturally occurring materials such as sugars and fatty acids. Half-lives for LAS mineralization ranged from 1-2 d in aerobic and anaerobic sewage sludges, river water and sediments, to 1-3 wk in surface and subsurface soils and estuarine environments. The half-life for LAS degradation in different environmental compartments, relative to its residence time in these compartments, makes biodegradation a practically significant removal mechanism in a broad range of aquatic, benthic and terrestrial habitats.