1. Bioremediation: The current and the future
Graeme Paton
Technical Director, Remedios
Diarmuid O’Sullivan
Senior Environmental Consultant

2. Bioremediation
“ The act of stimulating the metabolism or co-metabolism of contaminants in the natural environment. Can be ex-situ, in-situ or involve natural attenuation”
6 months - 3 years (ex-situ usually quicker)

3. Decomposition of biopolymers
Endoenzyme
Exoenzyme
Extracellular
enzymes ??
Endoenzyme
Exoenzyme
Dimers
Monomers
Cell
Oxidation
CO2
½ O2
H2O

4. Tool Kit
3 components
Induction
Constraints
Community

5. Induction
Catabolic biosensors enable a prediction of the bioavailability of the target molecule in that matrix
Hence if the genes for degradation are in the matrix, degradation is very likely

6. Tool Kit
3 components
Induction
Constraints
Community

7. Procedure for lux-based assay
100 %
% of the control luminescence
10 %
Increasing toxicity

8. Tool Kit
3 components
Induction
Constraints
Community

9. MPN- Tetrazolium
Paton et al 2003

10. Site Location- Oil spill 1

11. Tool Kit- at oil spill
Toxicity
Induction
mpn
TPH

12. Kuwait Oil Lake- Oil spill 2
During the first Gulf war ( ) 50 million tonnes of soil was contaminated
Air-borne oily material contaminated one thousand square kilometres of soil.

13. Systematic Grid

14. Can we predict? BF= Bioremediation
(f) [TPH] (f) availability (f) degraders (f) constraints
Induction x [TPH]
mpn
BF=
x (1-EC)

15. Prediction
Once all of the data have been integrated an estimation of the likely case for degradation can be made
Iroegbu et al., 2003

16. TPH
Week 0
Week 15

17. Prediction v Actual

18. Prediction
There is a close relationship between the predicted value and the actual hydrocarbon concentration.
This could define the end-point
Regular monitoring confirmed the progress of this work
This has been extended to over twenty trials to assess the value of the data

19. Prediction
Max specific
deg rate mg TPH/ day
Bioremediation Factor

20. Prediction
Max specific
deg rate mg TPH/ day
Bioremediation Factor

21. Gaswork Site- 10,000 tonnes

22. Bulk chemical- 2,500 tonnes

23. Coupling Technologies

24. The Big Issues
On four occasions we have been required to seed/ augment a biological treatment process. This is a growing issue and a commercial opportunity.

25. Bioaugmentation Agents
Inoc. Source
Pre-condition
1, 2, 3, 4
Substrate
Remedios
Nutrients
Soil
Solution

26. Examples of Data

27. What does this mean? Oil Technics- cfu= 108; mpn- 107
Supplier 1- cfu= 106; mpn- 104
Supplier 2- cfu= 106; mpn- 105
Supplier 3- cfu= 104; mpn- 103
Oil Technics and precondition- cfu= 109; mpn- 107
Supplier 1 and precondition- cfu= 108; mpn- 105
Supplier 2 and precondition- cfu= 107; mpn- 106
Supplier 3 and precondition- cfu= 105; mpn- 103

28. Respiration
Respiration
Days

29. Degradation
TPH
Days

30. Prediction
Max specific
deg rate mg TPH/ day
Bioremediation Factor

31. Prediction
Max specific
deg rate mg TPH/ day
Bioremediation Factor

32. What does this mean Augmentation is possible
Steps are required to refine
Immobilisation of wood is not ideal
Cost issues and value of application need to be considered
Need to focus and develop the skill-base