Web-based Class Project on Geoenvironmental Remediation

1. BIOREMEDIATION Web-based Class Projecton Geoenvironmental Remediation Prepared by: Report prepared as part of course CEE 549: Geoenvironmental Engineering Winter 2013 Semester Instructor: Professor Dimitrios Zekkos Department of Civil and Environmental Engineering University of Michigan Sophia Alliota Josh Colley With the Support of:

2. What is Bioremediation? • Bioremediation refers to a number of technologies that treat contaminated soil and groundwater by using microorganisms

3. Applicability • To contaminants: • Organic • Excellent for biodegrading organic contaminants e.g. petroleum hydrocarbons, chlorinated and non chlorinated compounds, wood treating agents • Inorganic • Metal sulphides such as those found in Acid Mine Drainage (AMD) can be treated easily using passive anaerobic wetlands • Heavy metals can also be immobilized

4. To ground conditions: • Soil treatment • Almost all soils can be treated using bioremediation as long as the moisture content is adequate to support microorganisms • Low permeability soils can be hard to treat when trying to permeate amendments through the soil mass • Groundwater treatment • Soils of k=10-4 cm/s or greater are treatable • Again, soils with low k are hard to treat

5. Common Contaminants • Organic contaminants include: • Polycyclic Aromatic Hydrocarbons (PAHs) • E.g. benzene, toluene • Polychlorinated Biphenyls (PCBs) • Pesticides and herbicides • Chlorinated solvents • E.g. perchloroethene, trichloroethene • Inorganic: • Heavy metals • AMD effluent containing metal sulphides

6. Common Sources of Contamination • Underground Storage Tanks (USTs) • Leakage of fuels e.g. petroleum • Wood treating facilities • Preservatives such as creosote common • Arsenals • Chemical manufacturing plants

7. Theory • Fundamentally bioremediation uses microorganisms (e.g. bacteria, yeast and fungi) to break down harmful contaminants • This can be facilitated by using native indigenousmicrobesor by adding foreign exogenous ones to populate the soil • Different types of microorganisms function well in different conditions: • Oligotrophs function well in low carbon environments • Eutrophsfunction well in high carbon environments

8. (USEPA, 2012)

9. Microorganisms can break down contaminants: • Under aerobic (oxygen present) conditions: • Under anaerobic (oxygen not present) conditions: • E.g. fermentation, denitrification • Sulfate reduction in anaerobic wetlands

10. Conditions must be suitable to promote microbial activity • Temperature 15-45°C • pH ~7 • Moisture content 40-80% of field capacity • Oxygen >2mg/l (aerobic) or <2mg/l (anaerobic) • Nitrogen, Carbon, Phosphorous etc • Conditions can be improved be adding amendments • Oxygen Releasing Compounds, Nitrogen, Phosphorous

11. Flexible methods • Treatment methods can be: • In-situ (i.e. in the ground) • E.g. injection of amendments • Ex-situ (i.e. out of the ground) • E.g. composting, land farming • Aerobic or anaerobic Landfarming(ETec, 2013)

12. An example of an in-situ aerobic method for treating soil and groundwater (USEPA, 2001)

13. Advantages • Organic contaminants can be broken down into other nontoxic chemicals • Minimal equipment requirements • Can be used in-situ or ex-situ • Can treat wide range of contaminants • Low cost • $30-750 per cubic yard of soil • $33-200 per 1000 gallons of water • Good public perception since ‘natural’ process

14. Disadvantages • Contaminants may only be partially broken down creating toxic by-products • Sensitive to ground conditions • Monitoring to accurately track degradation • In ex-situ processes VOCs need to be controlled

15. Field Setup: In-situ Bioremediation  (Tlusty, 1999)

16. Field Setup: Ex-situ Bioremediation  (USEPA, 1995a)

17. Field Setup: Land Farming  (ETec, 2013)

18. Field Setup: Windrow  (Proper, 2013)

19. Case Study: French Limited Superfund Site • French Limited in Crosby, Harris County, Texas (EPA Region 6) was a 25-acre sand mining site from 1950-1965 • The primary contaminants in this waste were benzo(a)pyrene, vinyl chloride, and benzene • In 1987, the EPA decided to try bioremediation, which was the first time that technology was used at a Superfund site

20. Case Study: French Limited Superfund Site (EPA, 1993)

21. Case Study: French Limited Superfund Site • Bioremediation was chosen because it offered a less expensive option to destroy the same amount of waste as an incinerator in the same amount of time • In-situ slurry-phase bioremediation was conducted to remedy the site

22. Case Study: French Limited Superfund Site (EPA, 1993)

23. Case Study: French Limited Superfund Site • Treatment process took 11 months to treat 300,000 tons of soil and sludge • Post-treatment benzene concentrations 7-43 mg/kg • After initial remediation, the French Limited site has been revisited several times to mitigate contamination from floods

24. References • ETec Environmental Technologies LLC (2013). "Landfarming". ETec LLC. http://www.etecllc.com/landfarming-bioremediation.asp (March 13th 2013) • Tlusty, B. (1999) "In Situ Bioremediation of Tricholoroethylene". Resoration and Reclamation Review, Student Online Journal - Department of Horticultural Science, University of Minnesota, Vol 5, Number 2, 1-8. • Proper (2013). "PROPER Gallery - Bioremediation Gallery". Proper. http://proper.menlh.go.id/proper%20baru/html/menu%205/proper%20galery/biore%20galery.htm (March 13th 2013). • USEPA. (1993). "Superfund at Work: Hazardous Waste Cleanup Efforts Nationwide". USEPA. • USEPA. (2001a, September). "Use of Bioremediation at Superfund Sites". EPA 542-R-01-019. • USEPA. (2012, September). "A Citizen's Guide to Bioremediation". EPA 542-F-12-003.

25. More Information More detailed technical information on this project can be found at: http://www.geoengineer.org/education/web-based-class-projects/geoenvironmental-remediation-technologies