Comparison of Two Methods for Assessment of In Situ Jet-fuel Remediation Efficiency

Abstract

In 1997, total petroleum hydrocarbon (TPH) remediation started at a former Air Force Base, which operated from 1940 to 1991. TPH had been released to soil and groundwater at the site by military activities. The TPH was 70% jet fuel and the affected area covered 28 ha. Remediation involved a combination of technologies, including removal of volatile organic compounds using soil vapor extraction and air sparging, free product vacuum recovery and aerobic biodegradation of organics with oxygen supplied by the air sparging system, along with nutrient addition. The primary remedial method was found to be biodegradation, which has removed 93% of the contaminants from the site to date. A significant aspect of the remedial action was performance monitoring, including documentation of remediation efficiency. The goal of the research was to assess the relative accuracy of methods commonly used for monitoring in situ TPH remediation. Two such methods were selected for the research: monitoring change in soil TPH concentration (specified as nonpolar extractable substances) and monitoring respiration activity in soil with a subsequent stoichiometric mass balance to estimate the mass of TPH destroyed. The study demonstrated that both of the methods provided comparable results regarding the effectiveness of in situ TPH remediation, despite the fact that their methodologies are very different.

Linking Microbial Community and Catabolic Gene Structures during the Adaptation of Three Contaminated Soils under Continuous Long-Term Pollutant Stress

“…The high stability of the microbial community in the CZE soil was expected, given that it has been under bioremediation for years (29,42), and consequently the community in this soil should have been adapted to the degradation of aromatic compounds. In agreement, catabolic genes detected on the microarray are related to those observed in proteobacteria (Fig.…”

“…The reaction in CZE mi- crocosms is slight compared to the reactions in BRA and SUI microcosms. Due to long-term remediation (29,42), the community is stable and mainly composed of Beta-and Gammaproteobacteria; however, evidence for an adaptation of the metabolic web to the novel pollutant mixtures could be given. BRA and SUI soil harbored similar bacterial communities, and in both soils, extended incubation resulted in an enrichment of members of the Actinobacteria, which was also reflected in the enrichment of genes supposedly characterizing the core genome but also specific oxygenases dedicated to the metabolism of hydrophobic pollutants.…”

“…Three different contaminated soil samples were used in this study. The Czech (CZE) soil sample was provided by AECOM CZ s.r.o., Prague, Czech Republic, and was derived from a former army airbase at Hradcany, Czech Republic (29). The CZE soil had been under bioremediation treatment and contained residual concentrations of alkanes (C 10 to C 40 ; 96 mg/kg), benzene (0.02 mg/kg), toluene/ethylbenzene/xylenes (TEX; 330.6 mg/kg), and polycyclic aromatic hydrocarbons (PAHs; 0.22 mg/kg).…”

Magnetite Formation by the Novel Fe(III)-reducingGeothrix fermentansStrain HradG1 Isolated from a Hydrocarbon-Contaminated Sediment with Increased Magnetic Susceptibility

“…This site was heavily contaminated with petroleum hydrocarbons composed mainly of jet fuel, diesel and gasoline with an estimated total volume of 7,100 tons (Machackova et al 2012). Long-term remediation was applied from 1997 until 2008 including air-sparging and nutrient application, resulting in an enhanced natural degradation of the contaminants by the indigenous bacterial community (Machackova et al 2008). A side effect observed as a consequence of the air-sparging was a fluctuation of the groundwater table leading to periodically changing oxic-anoxic redox zones.…”

Biodegradation of asphalt by Garciaella petrolearia TERIG02 for viscosity reduction of heavy oil

“…This is most likely due to the complex molecular structure of asphaltene which makes it resistant to biodegradation thereby causing their accumulation in ecosystem where petroleum and its refining byproducts are spilled in either accidental or purposeful ways (Guiliano et al 2000). The focus of many studies has generally been bioremediation of total petroleum hydrocarbon (TPH) contaminated sites (Iturbe et al 2007;Machackova et al 2008) and not much detailed work has been done on asphaltene biodegradation. This technique of microbial degradation of asphaltene to recover heavy oils is of great value and needs to be explored and studied deeply.…”