Microbiological Oxidation of High Viscosity Bitumen in Soil

Abstract

This paper presents the results of an investigation of microbiological oxidation in the model soil system of high viscosity bitumen from the Bayan-Erkhet deposit (Mongolia) with a high content of heteroelements. It is shown that bitumen, being a mixture of high molecular weight components, has no inhibitory effect on the indigenous soil microflora. Its active growth in the presence of oil products starts without adaptation and lasts for a good part of experiment resulting in 15-30 fold excess of microorganisms over its reference number. The enzymatic activity of the contaminated soil increases by a factor of 1.5-2.0, which indicates an assimilation of various hydrocarbon compounds. The weight analysis revealed that the biodegradation of oil products after 180 days of the experiment was 50% of the initial contamination at initial waste oil concentration 50 g/kg (5%). The analysis by IR spectroscopy revealed an accumulation of oxygen-containing compounds which are intermediate products of bio-oxidation of bitumen components. The method of chromatography-mass spectrometry (GC-MS) revealed the ability of aboriginal soil microflora to mineralize virtually all hydrocarbons contained in the bitumen under study. Their biodegradation ranges from 18 to 97%. It was shown by the GC-MS method that high-molecular heteroatomic components of bitumen (resins and asphaltenes) also undergo a microbial degradation, since their molecular structure changed after the destruction. Thus, the number of structural units in a hypothetical molecule and that of heteroatoms increased due to the high content of oxygen-containing structures. In addition, the ratio of hydrocarbons (oils), resins, and asphaltenes contained in the sample is also changed.

Pre-evaluation of contaminated soil for oil field reactivation in Moloacan, Veracruz, Mexico

“…Likewise, a frequent characteristic detected was that the contaminants were below the rhizosphere or mixed with it (d and e of Figure II). This phenomenon coincides with that reported by Filatov et al (2018) (d and e) Waste pits, hydrocarbons were observed outside, all in the form of hardened and viscous aggregates (2-5 cm) throughout the profile and until reaching the phreatic level (90-110 cm). High stoniness, roots do not go beyond 20 cm, hydrocarbon contact was also observed with groundwater outside the waste pit and near the well.…”

Bacterial Diversity in the Asphalt Concrete Lining of the Upper Water Reservoir of a Pumped-Storage Scheme

“…In contrast with the bacterial strains isolated from natural asphalt sources, which were anaerobic, the abovementioned bacteria are facultatively anaerobic or aerobic [19]. According to the literature [28,[41][42][43][44][45], all bacterial genera identified in this work in the investigated blisters (Pseudomonas, Bacillus, Lysinibacillus, Staphylococcus, Rhodococcus, and Micrococcus) contain species that degrade polycyclic hydrocarbons/oil/asphalt. Bacteria of the genera Pseudomonas, Bacillus, and Rhodococcus show the ability to degrade and transform a wide variety of natural organic compounds via diverse catabolic pathways [24,44,46,47].…”