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 deco ntamination of the waste water from a garage and car-wash that was con taminated with anionic surfactants (57 mg l(-1)) and fuel oil (183 mg hydrocarbons l(-1)). The indigenous microorganisms degraded both conta minants efficiently after biostimulation by an inorganic nutrient supp ly. 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 da ys, 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 incre ase of the hydrocarbon biodegradation during the first 3 days of decon tamination, whereas biodegradation of anionic surfactants was inhibite d during: the first 21 days following inoculation. Bioaugmentation of the nutrient-amended waste water was without any effect.