Bioaugmentation of MTBE

1
Bioaugmentation of MTBE

• Successes, Challenges and Implications

2
Background on MTBE

• Fuel Oxygenate
• Slow to Biodegrade
• Water soluble
• More mobile than other fuel constituents
• Estimated 10,000 MTBE impacted groundwater sites
  in California

3
Biodegradation of MTBE

• Players
• Consortia
• BC-1, MC-100
• Pure Cultures
• Rhodococus, Methylobacterium, Arthrobacter
• Fungi?
• Metabolism
• Used as a carbon and energy source
• Aerobic
• Incomplete gt TBA, Acetone
• Mineralization gt CO2 H2O

4
What is Bioaugmentation?

• Definition Experimental pollution remediation
  technique that employees inoculating contaminated
  soil or groundwater with microbes capable of
  metabolizing the pollutant.
• Process
• Site Characterization
• Contaminant(s)
• Soil characteristics
• Hydrology
• System Design
• Microbe selection
• Delivery methods
• System Installation
• System Operation

5

• Field Study Port Hueneme, CA
• Biobarrier Experiment
• Control untreated
• O2 Only Biostimulation - promote naturally
  occurring metabolizers
• O2 BC-4 Bioaugmentation Seeding and
  promoting MTBE metabolizer

6
Results
The Bren Question- Is it cost effective?
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Bioaugmentation Feasibility Problems

• Abiotic Factors
• Soil/Water pH
• Soil morphology
• Chemical Toxins
• Temperature
• Biotic Factors
• Cometabolism
• Predation
• Substrate suitability / Competition

8
Possible Solutions

• Abiotic
• pH - injection of HCO3- or other nontoxic buffer
• Toxins - pretreatment-bioaugmentation?
• Temperature - difficult, heat/cool air feed?
• Soil morphology - tough to change the dirt
• Biotic
• Cometabolism - Kill
• Predation - Slaughter
• Competition - Murder
• Antibiotics tried and succeeded but good idea?
• Perhaps a rapidly degrading toxin

9
Conclusion

• Bioaugmentation proven successful (MTBE)
• BUT
• Requires a great deal of further research
• Requires acceptable conditions
• Environmental heterogeneity makes wide spread
  application difficult at this time

10
How groovy is bioaugmentation?

• Questions?