The natural bioremediation of the groundwater contaminated with diesel oil at a petrol station was evaluated by monitoring geochemical indicators and biodegradation tests in laboratory. During two years the groundwater was collected four times. Different physic-chemical parameters and the concentration of hydrocarbons were evaluated. Microbiological analyses consisted of total heterotrophic bacteria counting, verification of the presence of hydrocarbonoclastic bacteria and the biodegradability test using the redox indicator DCPIP. It was possible to identify factors that confirm the use of the natural bioremediation technique as a treatment to the groundwater, however, hydrocarbons retained in the soil represent a continuous source of contamination, and for this reason, a long term monitoring is necessary.
Natural bioremediation; geochemical indicators; groundwater; petrol stations
