Estudos microbiológicos para tratamento de água subterrânea de áreas contaminadas por hidrocarbonetos

Abstract

The compounds known as TPH (Total Petroleum Hydrocarbon) and BTEX (Benzene, Toluene, Ethylbenzene and Xylene) contaminants are derived from petroleum products like gasoline and diesel. They are problems that occur from the underground storage of fuels, especially in gas stations. They are found in areas of groundwater contaminated with hydrocarbons, which cause environmental impact. Examples of these impacts may include: destruction of the points of capitation of drinking water, the death of aquatic flora and fauna, destruction of crops and plantations, soil sealing, reduction of soil microorganisms, death of plants and trees, and hazards of explosion due to the evaporation of the product. This research evaluated through microbiological methods, such as: microbial growth, selective medium for fungi, isolation, detection ramnoli and biodegradability test, the processes involved in the recovery of degraded sites by hydrocarbons through at the isolation and characterization of microorganisms present on the site contaminated. Different concentrations of diesel oil (1%, 2%, 3%, 5%, 10%, 30% and 50%) were tested to assess the growth of microorganisms indigenous of contaminated gas station, and to identify the potential degradation of hydrocarbons. Accompaniments visual and microscopic, in addition to monitoring the reduction of the parameter TPH in several tests were performed. The results showed that it was possible to isolate and characterize microorganisms in the contaminated site, where two different morphotypes were observed: bacteria and fungi, and 81.8% Gram-negative bacteria, Gram-positive bacteria 4.5% and 13.7% fungi. In tests with lower concentrations of diesel oil (1%) had the better growth of microorganisms resulting in greater efficiency in reduction of TPH. These results indicate the possibility of degradation of diesel in areas contaminated by biological, with exceptions for high concentrations of hydrocarbon, when microbial growth was affected.