1. Bioremediation of subsurface oil in a tidally-influenced sand beach: Impact of hydraulics and interaction with pore water chemistry
Xiaolong (Leo) Geng, PhD
Center for Natural Resources Development and Protection
Department of Civil and Environmental Engineering
New Jersey Institute of Technology

2. Co-authors Funding Michel C. Boufadel, NJIT
Kenneth Lee, Commonwealth Scientific and Industrial Research Organization (CSIRO)
Stewart Abrams, Langan Engineering Inc.
Funding
National Oceanic and Atmospheric Administration
National Science Foundation
Department of Fisheries and Oceans, Canada

3. Oil biodegradation in the intertidal zone of a beach in the GOM

4. Oil biodegradation in the unsaturated zonemi

5. BIOB model description
BIOB (BIO-Batch) is a numerical model to simulate the aerobic hydrocarbon biodegradation in porous media in a given volume.
Oil biodegradation
Hydrocarbon
Hydrocarbon degrader mi
Term Function:
Biodegradation
Physical removal
Biodegradation
Physical removal

6. Continued Monod kinetics Oxygen consumption Limiting factors:
Field capacity
Substrate
Nutrient
Oxygen
Oxygen consumption mi
Geng, X., Boufadel, et. al., 2013, Biodegradation, 24 (2):
Geng, X. Boufadel, et al., Marine Pollution Bulletin, 83 (1),
Torlapati and Boufadel, 2014, Frontiers in Microbiology, 5, 212.

7. Aromatics
Can you make the axes titles and numbers larger? mi

8. Aromatic Degraders
Can you make the axes titles larger? mi

9. Oxygen Consumption mi

10. Water flow and solute transport in beaches
MARUN (MARine Unsaturated) Model
Two-dimensional finite element model MARUN (Boufadel et al. 1999)
Considers water flow below and above the water table
Accounts for water salinity on water density and viscosity.
Boufadel, et al., Journal of Contaminant Hydrology, 1999, 37(1): 1-20.
Boufadel, et al., Water Resources Research, 2000, 36(9):
Boufadel and Xia, Environmental modeling and software, 2011, 26(7):

11. MARUN validation: Tide
Li and Boufadel, NATURE Geoscience, 2010, 3(2):
Guo et al., Journal of Geophysical Research, Oceans, 115, C12077, 2010.
Xia, et al., Water Resources Research, Vol. 46, W10528, 17p, 2010.

12. MARUN Validation: Waves
Geng, X. et al., Journal of Contaminant Hydrology, 165:
Geng, X., Boufadel, M.C., Journal of Geophysical Research: Oceans. doi: /2014JC

13. BIOMARUN model description
MARUN + BIOB = BIOMARUN
Eight equations: subsurface water flow, fates of dissolved salts, two types of substrate (i.e., hydrocarbon), two types of degraders, dissolved oxygen, and nutrient (nitrogen)
Oil is attached in the beach
Oxygen is replenished from atmosphere, inland and sea
Nutrient (i.e., nitrogen) is replenished from inland and sea
Indigenous microorganisms are assumed present mi

14. Simulation Conditions
100 mg/kg sediment for long-chain alkanes and 50 mg/kg sediment for aromatics
Concentration of dissolved oxygen is 8.2 mg/L from inland and sea
Background conc for alkane degraders is 6×10-2 mg/kg
Background conc for aromatic degraders is 6×10-4 mg/kg
High tide= 3.95 m
Low tide=3.35 m
Inland WT = 3.75 m
1.2 mg-N/L
0.2 mg-N/L

15. Oxygen distribution

16. Nitrogen distribution

17. Beach-wise variation using BIOMARUN

18. Intertidal zone oil biodegradation
Shallow location
You could zoom in more on the intertidal zone of the beach. You could put the x axis at the level of the low tide line.
Deep location

19. Mid intertidal zone

20. Bioremediation
Figure: Alkane biodegradation at different application rate
Figure: Alkane biodegradation at different application duration.
Figure: Biochemical residence time map (BRTM) in the beach at Cthreshold = 2.0 mg-N/L

21. Conclusion
The aerobic biodegradation of oil in tidally influenced beaches was investigated in this work using realistic beach and tide conditions.
Simulation resulted uneven oil biodegradation. In the upper intertidal zone, where the inland incoming nutrient concentration is large (1.2 mg/L), oil biodegradation occurred deeper in the beach in comparison with shallow zones.
In the mid-intertidal zone, a reversal was noted where the biodegradation was fast at shallow locations in comparison with deep locations.
Oxygen concentration in the mid-intertidal zone exhibited two peaks as function of time. One peak was associated with the high tide, and a second oxygen peak was due to replenishment of the pore by oxygen from the atmosphere.

22. Thank you
Questions?