Microbiology of domestic wastes. 3. Metabolism of LAS-type detergents by bacteria from a sewage lagoon.

Abstract

Linear alkylate sulfonate (LAS) detergents Liqui-nox, commercial LAS, C11.3 LAS, C13.3 LAS, α-11 LAS, and α-14 LAS were metabolized very readily by mixed cultures of bacteria recovered during summer from a sewage lagoon; at least 97.5% of each LAS detergent was biologically removed under the experimental conditions used. The organisms were sensitive to temperature changes; α-14 LAS and Liqui-nox were used more slowly at 10 °C than at 25 °C but were not metabolized at 2 °C. Liqui-nox, the only detergent tested anaerobically, was not degraded in the absence of molecular oxygen. ABS was not metabolized under any of the experimental conditions.Bacteria recovered from under an ice cover during winter were not able to metabolize any of the detergents under any of the experimental conditions tested.The significance of these results is discussed for lagoon management in respect to seasonal change.