2.5. Developing Bioremediation Technology for the Cleanup the Oil-Contaminated Onshore Areas in the Arctic

The Project Goal was to (i) develop bioremediation technology for the cleanup the oil-contaminated onshore areas that could be applied in both the Russian and foreign areas in the Arctic; and (ii) disseminate successful experience of the Project.

The Project was implemented by Limited Liability Company "NavEcoservis" (OOO "NavEks").

The Project Duration:                                   01 July 2008 - 16 June 2009;

The Project Activities

The following activities were carried out to meet the Project goal:

• Analysis of the Russian and international experience in bioremediation of soils polluted with oil products at low temperatures;
• Selection of a bioremediation site and equipment;
  

  
  Figure 12. Overview of the Site

• Field studies and laboratory essay of the samples;
• Review of the sample laboratory essays to identify the best types of biological products and their application methods for different types of oil products;
• Review of the results and development of the draft Guidelines for Bioremediation of Oil-Contaminated Soils in the Arctic;
• Preparing and holding workshop to discuss the results, draft Guidelines and dissemination of best practices for Bioremediation of Oil-Contaminated Soils in the Arctic.

The Project Outcomes

1. The soil texture, which is characteristic of northern latitudes, is neither toxic nor pathogenic;
2. The soils, that are the most typical of northern latitudes, have low biogenic levels and as such they have very low self-purification capacity;
3. It was noted that the soil natural microflora demonstrated resistance to the lowering of temperature;
4. Activation of the native flora can trigger a positive effect only where contamination levels are low (1-2%);
5. In the main section of the remediation site, the biological product "Roder" was the best performer (4,5-5,3%) in the treatment of mazut contaminated soil, DEVOROIL performed best in the treatment of diesel fuel contaminated soil (4,8-5,9%), while Mikrozim (tm) «PETRO rub" and "Roder" did the best job in the treatment of oil contaminated soils (6,7%).
6. In the engineering section of the bioremediation site, because of the constant above-zero temperature of the soil, the biological products demonstrated a higher degree of decomposition of petroleum products as compared with the main section. The best result in the treatment of soil from fuel oil and diesel fuel was shown by "Mikrozim (tm) “PETRO rub", while DEVOROIL worked best on oil.
7. In the Arctic conditions, microbial agents are more effective as compared with agricultural method of remediation.
8. Biological products have a positive enhancing effect on the biological activity of soil and, consequently, accelerate decomposition of oil spills;
9. Pre-activation of biological products is recommended (preparation of working suspensions), reducing the period of bacteria activation in the soil;
10. The soil peat serves as: (i) a natural sorbent agent, which reduces the penetration of oil into the soil; (ii) water-holding substance, supporting the soil humidity levels required for bacteria; and (iii) natural organic fertilizer, contributing to the intensification of remediation in the soil;
11. Application rates of fertilizers and biological products are to be strictly calculated and controlled since excessive doses of mineral fertilizers cause soil acidification and this reduces the remediation capacity of contaminated soil substrates.
12. It is important to maintain the necessary (40-70%) soil moisture, since soil overwetting can have a negative effect on soil phytoremediation.

Figure 13. Layout of Soil Heating and Aeration System

1. Soil aeration (loosening, milling, etc.) contributes to the uniform distribution of hydrocarbon-oxidizing microorganisms within soil, to aeration and, as a result, to еру intensification of oil biodegradation;
2. If it is no possible to do aeration by loosening or milling (permafrost is very close to the works site, of the remediation area can not be accessed by machinery), in addition to biological products, we recommend that natural sorbents (peat, sawdust, moss, etc.) be applied into the soil.
3. Biological products are most effective at above-zero temperatures.
4. The microbiological analysis suggests that bacteria keep on working as temperatures go down even if soil freezes. However, their activity decreases as soil temperature goes down.
5. It is recommended to use phytoremediation phase at the final stage of bioremediation (seeding oil pollution resistant plants).

The results of the studies suggest that bioremediation of oil-contaminated soils in the Arctic is a promising method. This conclusion was also confirmed by the project outcomes meeting, which was held on June 16, 2009 in the Murmansk Oblast Committee of Natural Resources Management and Ecology.

One of the main achievements of this work is the application of special technologies and engineering solutions to bioremediation, enabling the continuation of the oil products biodegradation process throughout the calendar year.

The experiment proved that it was possible to use biological products in the Arctic.

The limited period of the studies did not permit any final or unequivocal conclusions about advantages of this or that biological product as applicable to a type of pollution in the Arctic conditions. It is also rather difficult to determine deadline for the completion of the bioremediation process full cycle. Based on the results, one may suggest that the soil remediation process at the remediation site may take from two to four and a half years depending on the technologies applied and provided all the specifications for the use of biological products and soil remediation process in the Arctic conditions are complied with (Figure 15).

Phytoremediation should be the final stage of biological remediation. This stage include the following steps: (i) selecting remediation grass species; (ii) calculating seeding rates; (iii) seeding and monitoring germinating capacity and growth of the grass. Depending on the contamination levels and climatic conditions, there might be a need in overseeding.

The existing phytoremediation methods could remediate soils till they reach the permissible residual concentrations (PRC) for oil and oil products.

Establishing PRC for soils in Murmansk Oblast was one of the issues that was raised when discussing remediation practice in other constituent subjects of the Russian Federation. With no PRC, one has to remediate soil till there is zero concentration of oil or oil products in the soil and this poses a problem in the Arctic conditions.

Figure 14. Map of Environmentally Hazardous Facilities in Murmansk Oblast and Oil and Oil Products Transportation Routes

Table of Contents