May 2004
STUDY DEMONSTRATES ULTIMATE BIODEGRADATION OF LAS IN SEAWATER
(Washington, DC) – Linear alkylbenzene sulfonate (LAS) and its breakdown products biodegrade rapidly in seawater, demonstrating that LAS released into marine environments through wastewater effluents should be effectively eliminated by aerobic biodegradation, according to research from the University of Cadiz in Spain.
Previous studies have demonstrated that LAS, the most commonly-used cleaning agent (surfactant) in household laundry detergents, undergoes biodegradation in marine environments. This is the first study to demonstrate that sulfophenylcarboxylic acids, or SPCs, are also biodegraded in seawater. SPCs are the breakdown products of primary LAS biodegradation.
In this laboratory study, published in the April issue of Environmental Science & Technology (vol. 38, no. 4), researchers spiked natural marine water with concentrations of LAS and SPCs similar to those found in coastal waters impacted by effluent discharges, and exposed the samples to conditions intended to mimic the coastal environment. The researchers reported biodegradation of LAS to exceed “99 percent in all tests performed.” The study concludes that “the total disappearance of the SPCs in all cases indicates that the degradation of LAS in seawater at the tested concentrations in aerobic conditions is completed.”
This new study adds to the already extensive body of research demonstrating the environmental safety of LAS. The surfactant has been shown to undergo complete and rapid biodegradation in the presence of oxygen in many other environmental compartments.
Abstracts of the study can be found on the ES&T website.