Changes in total oil hydrocarbon composition during degradation with sorbent bacterial preparation

  • Indrė GAILIŪTĖ


Accidental or deliberate spillage of crude oil into the environment is leading to serious pollution problems. Therefore, these areas of oil pollution can be decontaminated by microorganisms. However, biological degradation capabilities of oil and its derivatives, also their effect on living organisms and on the environment varies. Microorganisms that degrade oil hydrocarbons are found in almost all types of soil; however, their existence does not guarantee the effective degradation of oil pollutants. In order to evaluate capabilities of newly developed SORBENT bacterial preparation (SBP) to degrade heavy hydrocarbons, degradation dynamics was observed in different soil types: loam, clay and sand, using crude oil and fuel oil mixture (1 : 1). Therefore, correlation between the intensity of oil component degradation and temperature as well as a correlation between the intensity of oil fraction degradation and the amount of SBP were evaluated. According to experimental data, soil samples polluted with heavy hydrocarbons and treated with SBP, during the first 9 weeks of biodegradation were composed of: up to 20–30% of alkanes, 30–50% of aromatic compounds, 50–60% of resins and 9–44% of asphaltenes. The investigations revealed that less polluted soil (up to 100 g/kg) treated with microorganisms was degraded almost 6 times better than heavily polluted soil (350 g/kg). Therefore, it can be stated that SBP is very effective in the degradation of all types of oil hydrocarbons, including resins and asphaltenes, which are known as the most difficult ones to degrade. This paper reflects findings from the EU funded 7th Framework programme project “SORBENT” (232533). Keywords: bacterial preparation, heavy oil hydrocarbons, oil degradation, oil fractions, soil pollution