Low-temperature bioremediation of a waste water contaminated with anionic surfactants and fuel oil

We conducted a laboratory study at 10 degrees C on the biological decontamination of the waste water from a garage and car-wash that was contaminated with anionic surfactants (57 mg l(-1)) and fuel oil (183 mg hydrocarbons l(-1)). The indigenous microorganisms degraded both contaminants efficiently after biostimulation by an inorganic nutrient supply. after 7 days at 10 degrees C, the residual contaminations were 11 mg anionic surfactants l(-1) and 26 mg hydrocarbons l(-1). After 35 days, only the anionic surfactants had been further reduced to 3 mg l(-1). Bioaugmentation of the unfertilized waste water with a cold-adapted inoculum, able to degrade both hydrocarbons (diesel oil) and anionic surfactants (sodium dodecyl sulphate), resulted in a significant increase of the hydrocarbon biodegradation during the first 3 days of decontamination, whereas biodegradation of anionic surfactants was inhibited during: the first 21 days following inoculation. Bioaugmentation of the nutrient-amended waste water was without any effect.