Biodegradation of sodium linear alkylbenzenesulfonates evaluated with a soil perfusion method.

In order to explain biodegradation behavior of sodium alkylbenzenesulfonate (LAS) in the soil environment, a soil perfusion method has been applied. This method is one of continuous enrichment cultures with soil. The degree of degradation of LAS was evaluated by measuring the amount of ferroin reagent active substances (FRAS) instead of methylene blue active substances (MBAS) and/or of total organic carbon (TOC) in the perfusion fluid. The biodegradation of LAS started after adsorption onto soils. At high LAS concentrations, the biodegradation occurred after some lag phase, but further added LAS was degraded readily without a lag phase. These results of biodegradation are in good agreement with those obtained from the biodegradation tests on river water and activated sludge, and reproducible results were obtained for the soil perfusion with the same soil. This proves the soil perfusion method to be a useful method for evaluation of biodegradation in the soil environment. [ABSTRACT FROM AUTHOR]