Remediation of hydrocarbon contaminated soils in the Canadian Arctic by landfarming (original) (raw)
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On site bioremediation of hydrocarbon-contaminated Arctic tundra soils in inoculated biopiles
Applied Microbiology and Biotechnology, 2001
There is a need to develop technology to allow the remediation of soil in polar regions that have been contaminated by hydrocarbon fuel spills. Bioremediation is potentially useful for this purpose, but has not been well demonstrated in polar regions. We investigated biopiles for on-site bioremediation of soil contaminated with Arctic diesel fuel in two independent smallscale field experiments at different sites on the Arctic tundra. The results were highly consistent with one another. In biopiles at both sites, extensive hydrocarbon removal occurred after one summer. After 1 year in treatments with optimal conditions, total petroleum hydrocarbons were reduced from 196 to below 10 mg per kg of soil at one site, and from 2,109 to 195 mg per kg of soil at the other site. Addition of ammonium chloride and sodium phosphate greatly stimulated hydrocarbon removal and indicates that biodegradation was the primary mechanism by which this was achieved. Inoculation with cold-adapted, mixed microbial cultures further stimulated hydrocarbon removal during the summer immediately following inoculation. At one site, soil temperature was monitored during the summer season, and a clear plastic cover increased biopile soil temperature, measured as degree-day accumulation, by 30-49%. Our results show that on-site bioremediation of fuel-contaminated soil at Arctic tundra sites is feasible.
Bioremediation treatment of hydrocarbon-contaminated Arctic soils: influencing parameters
Environmental science and pollution research international, 2014
The Arctic environment is very vulnerable and sensitive to hydrocarbon pollutants. Soil bioremediation is attracting interest as a promising and cost-effective clean-up and soil decontamination technology in the Arctic regions. However, remoteness, lack of appropriate infrastructure, the harsh climatic conditions in the Arctic and some physical and chemical properties of Arctic soils may reduce the performance and limit the application of this technology. Therefore, understanding the weaknesses and bottlenecks in the treatment plans, identifying their associated hazards, and providing precautionary measures are essential to improve the overall efficiency and performance of a bioremediation strategy. The aim of this paper is to review the bioremediation techniques and strategies using microorganisms for treatment of hydrocarbon-contaminated Arctic soils. It takes account of Arctic operational conditions and discusses the factors influencing the performance of a bioremediation treatme...
Cold Regions Science and Technology, 2013
A laboratory feasibility study on the bioremediation of hydrocarbon-contaminated soil from an Alpine former military site was conducted over a period of 30 weeks. We determined the effects of temperature (10°C and 20°C) and of various biostimulation treatments (inorganic nitrogen-phosphorus-potassium fertilization and the two commercial products Inipol EAP22 and Terramend) versus natural attenuation on the loss of total petroleum hydrocarbons, microbial activity (soil respiration) and community composition (phospholipid fatty acids). The hydrocarbon contamination was removed almost completely (up to 92.7%) at 20°C, at 10°C losses up to 69% were obtained. Biostimulation by the addition of nutrients had a significantly stimulating effect on the biodegradation activity of the indigenous soil microorganisms, however, a considerable amount of hydrocarbon loss could be attributed to natural attenuation. Shifts in microbial community composition during bioremediation
Polar Biology, 2007
A Weld study was initiated in December 2000 in two selected sub-Antarctic soils (Kerguelen Archipelago) with the objective of determining the long-term eVects of a fertilizer addition on the degradation rate and the toxicity of oil residues under severe sub-Antarctic conditions. Two soils were selected. The Wrst site was an organic soil supporting an abundant vegetal cover while the second one was a mineral soil, free from vegetation. Both soils were located in the vicinity of the permanent station of Port-aux-Français (69°42ЈE¡49°19ЈS). Two series of Wve experimental plots (0.75 £ 0.7 5 m) were settled Wrmly into each of the studied soils. Each plot received 500 ml of diesel fuel or Arabian light crude oil and some of them were treated with a bioremediation agent: the slow release fertilizer Inipol EAP-22 ® (Elf Atochem). All plots were sampled on a regular basis over a 4-year period. The microbial response was improved by bioremediation treatments but fertilizer addition had a greater impact on the mineral soil when compared to the organic one. The rate of degradation was signiWcantly improved by bioremediation treatments. However, even after 4 years, the toxicity of oiled soils as determined by Microtox solid phase tests showed a persistent response in spite of an apparent signiWcant degradation of alkanes and aromatics. Despite the very small amount of contaminant used in this experiment, 4 years of bioremediation was not suYcient to obtain a complete return to pristine conditions
Environmental Technology, 2014
One of the preferred methods for the remediation of fuel contaminated soil today is landfarming. This is particularly true for remote sites because the method requires minimal equipment and is therefore by far the lowest cost option. The term landfarming generally refers to the process whereby hydrocarbon contaminated soils are spread out in a layer about half a meter thick, nutrients are added, and periodically the soils may be mixed. During landfarming, hydrocarbons can be lost through volatilization or bioremediation and thus landfarming refers to the combination of the two processes.
Bioremediation of hydrocarbon-contaminated polar soils
Extremophiles, 2006
Bioremediation is increasingly viewed as an appropriate remediation technology for hydrocarboncontaminated polar soils. As for all soils, the successful application of bioremediation depends on appropriate biodegradative microbes and environmental conditions in situ. Laboratory studies have confirmed that hydrocarbon-degrading bacteria typically assigned to the genera Rhodococcus, Sphingomonas or Pseudomonas are present in contaminated polar soils. However, as indicated by the persistence of spilled hydrocarbons, environmental conditions in situ are suboptimal for biodegradation in polar soils. Therefore, it is likely that ex situ bioremediation will be the method of choice for ameliorating and controlling the factors limiting microbial activity, i.e. low and fluctuating soil temperatures, low levels of nutrients, and possible alkalinity and low moisture. Care must be taken when adding nutrients to the coarse-textured, low-moisture soils prevalent in continental Antarctica and the high Arctic because excess levels can inhibit hydrocarbon biodegradation by decreasing soil water potentials. Bioremediation experiments conducted on site in the Arctic indicate that land farming and biopiles may be useful approaches for bioremediation of polar soils.
Bioremediation treatability assessment of hydrocarbon-contaminated soils from Eureka, Nunavut
Cold Regions Science and Technology, 2001
The bioremediation potential of three hydrocarbon-contaminated soil samples with diverse soil physicalrchemical characteristics from Eureka, Ellesmere Island, Nunavut, was assessed. Microbial enumeration by viable plate counts and Ž . Ž q MPN analyses combined with molecular analysis PCR and colony hybridization for hydrocarbon catabolic genes alkB , q q . xylE , ndoB demonstrated the presence of significant numbers of aerobic cold-adapted hydrocarbon-degrading organisms in the three contaminated soils. The degradative activities of the indigenous microbial populations were assessed by 14 Ž
Cold Regions Science and Technology, 2007
Full-scale in situ remediation of diesel-contaminated soils has not yet been used in Antarctica. This is partly because it has been assumed that temperatures are too low for effective biodegradation. To challenge this idea, the effects of temperature on the hydrocarbon mineralisation rate have been quantified during mesocosms, biopiles and field pilot studies carried out on an artificially contaminated subAntarctic soil. Field studies were initiated in December 2000 in a selected soil of The Grande Terre (Kerguelen Archipelago,. Four experimental plots (0.75 Â 0.75 m) were settled firmly into the studied soil. Each plot received 500 mL of diesel fuel and two of them were covered with a black plastic sheet. All plots were regularly sampled over a oneyear period. Under natural subAntarctic conditions, the field tests revealed that up to 95% of the contaminants were degraded within one year, indicating that low temperatures (0-7 8C) can still accommodate oil biodegradation by indigenous microorganisms. Covering the soil with plastic sheets induced a small but permanent increase of the temperature in the surface soil (annual mean of + 2.2 8C). The microbial response was improved by this bioremediation treatment. Mesocosm studies and pilot biopile experiments confirmed that a constant heating of soil could be an effective mean to accelerate bioremediation of diesel-contaminated subAntarctic soils. However, the microbial response was always improved by a complementary fertilizer addition. D
International Biodeterioration & Biodegradation, 2012
Under Antarctic conditions, bioremediation processes are highly limited. Although chronically contaminated soils seem to require no bioaugmentation, biostimulation proved to be beneficial although diverse results have been reported in relation to the type of nutrient source and the best experimental design. In this work we evaluated, in "on site" land plots, the effect that on the hydrocarbon removal and bacterial community structure of a fuel contaminated soil have an inorganic salts mixture, a complex organic matrix (fish meal) and a commercial product listed by the EPA. Also the effect of a surface active compound (Brij700) on biodegradation process was studied. Brij700 did not improve biodegradation in any of the studied conditions but induced relevant changes on bacterial community of soil amended with fish meal. Although fish meal significantly enhanced bacterial counts, this effect was unspecific, drastically changed the bacterial community structure and did not improve hydrocarbon removal. Salts amended systems evidenced a non significant decrease in contaminant concentration. Commercial product caused the higher reduction (49.4%, p < 0.05) of hydrocarbons compared with the control system after 45 d of treatment and cause the minor changes in bacterial community, constituting a promising alternative for some hydrocarbon-contaminated Antarctic soil restoration.