Project Title:  Assessment of Surfactant-Enhanced Bioremediation for Soils/Aquifers Containing
Polycyclic Aromatic Hydrocarbons

Principal Investigator: Peter R. Jaffé

Source of Funding:  EPA, DoD

Project Summary:  Bioavailability of low-solubility hydrocarbons in soils is limited by their sorption onto the soil matrix.  Surfactants above their critical micelle concentration enhance desorption of these hydrocarbons, and as the investigators have shown, the fraction dissolved in the micelles can be bioavailable.  Surfactant-enhanced bioremediation of soils containing low-solubility hydrocarbons is a promising bioremediation technique, that needs further evaluation.  The surfactant /pollutant behavior in soils is complex, since surfactants may solubilize the pollutants, but may also sorb onto the soil, providing an additional phase that increases sorption, and may also have an oxygen demand.  The proper selection of a surfactant and its dose depends on site-specific conditions.  Through column experiments and modeling, we will develop a methodology to evaluate this bioremediation technique, and its design / operation for different field conditions.

Relevant Publications:
Guha, S., and P.R. Jaffé, “Biodegradation Kinetics of Phenanthrene Partitioned into the Micellar-Phase of Non-ionic Surfactants,” Environmental Science and Technology, Vol. 30, No. 2, 1996, pp. 605-611.
Guha, S., and P.R. Jaffé, “The Bioavailability of Hydrophobic Compounds Partitioned into the Micellar Phase of Nonionic Surfactants,” Environmental Science and Technology, Vol. 30, No. 4, 1996, pp. 1382-1391.
Guha, S., and P.R. Jaffé, “Determination of Monod Kinetic Coefficients for Volatile Hydrophobic Organic Compounds,”Biotechnology and Bioengineering, Vol. 50, No. 6, 1996, pp. 693-699.
Guha, S., P.R. Jaffé, and C.A. Peters, “Solubilization of PAH Mixtures by a Non-Ionic Surfactant,” Environmental Science and Technology, Vol. 32, No. 7, 1998, pp. 930-935.
Guha, S., P.R. Jaffé, and C.A. Peters, “Bioavailability of Mixtures of PAHs Partitioned into the Micellar Phase of a Non-ionic Surfactant,” Environmental Science and Technology, Vol. 32, No. 15, 1998, pp. 2317-2324.
Guha, S., C.A. Peters, and P.R. Jaffé, “Multi-Substrate Biodegradation Kinetics of Naphtalene, Phenanthrene and Pyrene Mixtures,” Biotechnology and Bioengineering, in press.
Brown, D.G., S. Guha, and P.R. Jaffé, “Surfactant-Enhanced Biodegradation of a PAH in Soil Slurry Reactors,” Bioremediation Journal, in press.
 

Project Title:  Trace Metal Bioremediation:  Assessment of Model Components from Laboratory and Field Studies to Identify Critical Variables

Principal Investigator(s):  Peter R. Jaffé, Herschel A. Rabitz

Source of Funding:  DoE

Project Summary:  The mobility and transport of trace metals in groundwater systems is strongly affected by biological activities.  Biological processes can be exploited to immobilize trace metals or alternatively mobilize them to accelerate cleanup of contaminated sites.  Ongoing efforts of researchers at DoE are focusing on the many biological and geochemical processes that impact trace metal mobility in groundwater systems.  The proposed research aims to lay the foundations for constructing reliable models.  An assessment will be made on the laboratory and field data needed to generate a hierarchy of models of varying fidelity.  The study will involve surveying the current DoE experimental efforts and contacting the PI’s as well as drawing together a prioritized host of modeling tools and issues.  The outcome of this study will be a document presenting a set of plans, needs, and recommendations for generating a set of models with the aim for coordinating with DoE experiments to assess the fate of trace metal and radionuclide contaminants in groundwaters during bioremediation processes.
 
Relevant Publications:
P.R. Jaffé, S. Wang, and H.A. Rabitz, G. Li, and S.W. Wang, “Simulating Bioremediation of Uranium Contaminated Aquifers; An Evaluation of Model Robustness,” presented at the 1999 International Symposium on Subsurface Microbiology, Vail, CO.
S. Wang, G. Li, and S.W. Wang, H.A. Rabitz, and P.R. Jaffé “New Techniques to Analyze Model Outputs; an Example of Trace-metal and Radionuclide Bioremediation,” in preparation.
S. Wang, and P.R. Jaffé, “Modeling the Bioremediation of Uranium in Groundwaters,” in preparation.
 

Project Title:  Modeling the Degradation of Hydrocarbons in Sediments; Bridging the Gap between Molecular Processes and Fate and Transport Modeling
 
Principal Investigator(s):  Peter R. Jaffé

Source of Funding:  NSF – Center for Bioinorganic Chemistry (CEBIC)

Project Summary:  Petroleum hydrocarbons can be biodegraded in marine and freshwater sediments following a spill.  The dynamics of hydrocarbon biodegradation by mixed bacterial populations, and the distribution of different hydrocarbon degraders along the sediment redoxcline are poorly understood.  Hence, major simplifying assumptions need to be made to predict the fate of hydrocarbons in sediments.  The proposed work will use molecular-scale information from ongoing CEBIC projects and in collaboration with these CEBIC PI’s develop new means to model in a more realistic and hence accurate manner the fate of hydrocarbons in sediments.  The two major new questions that this project will address, and incorporate into a numerical model to assess the fate of hydrocarbons in sediments are:  (1) What is the distribution, activity, and overlap of different bacterial populations degrading the same hydrocarbon (i.e. aerobes and denitrifiers) near and at redox transition zones, and what factors affect this distribution?  (2) For mixed populations, are the degradation mechanisms, and hence the required kinetic formulation of mineralization of the hydrocarbon dependent on the concentration of the terminal electron acceptor?

Relevant Publications:
New project to start September 1999. Related publications include:
Park, S.S., and P.R. Jaffé, “A Numerical Model to Estimate Sediment Oxygen Levels and Demand,” Journal of Environmental Quality, Vol. 28, 1999, pp. 1219-1226.
Guha, S., C.A. Peters, and P.R. Jaffé, “Multi-Substrate Biodegradation Kinetics of Naphtalene, Phenanthrene and Pyrene Mixtures,” Biotechnology and Bioengineering, in press.
 

Project Title:  Integrating Models of Citizens Perceptions, Metal Contaminants, and Wetland Restoration in an Urbanizing Watershed.

Principal Investigator(s):  Peter R. Jaffé and Robert K. Tucker (Stoney Brook Millstone Watershed Association)

Source of Funding:  EPA

Project Summary:  Watershed maintenance and restoration are critically dependent on public understanding and support for the vital role wetlands play in water quality and ecological integrity of watersheds.  Wetlands play a vital part in sequestering toxic metals, thus inhibiting non-point runoff to surface waters.  We propose an integrated systems perspective, studying the environmental quality perceptions of citizens with competing land-use interests, interactions of municipal policy, volunteer watershed restoration efforts, wetland plant community composition and trace metal behavior.  We intend to link an ecological model of metal behavior influenced by redox conditions in wetlands soils, as affected by plant species composition, with a sociological study of citizen perceptions of ecological quality.  We will investigate how such perceptions may change with benefit of information from the wetlands/metal research.

Relevant Publications:  Project to start Summer 1999.  Related publications include:
Park, S.S., and P.R. Jaffé, “Development of a Redox Potential Model for the Assessment of Postdepositional Heavy Metal Mobility,” Ecological Modelling, Vol.91, No. 1-3, 1996, pp. 169-181.
Smith, S.L., and P.R. Jaffé, “Modeling the Transport and Reaction of Trace Metals in Water-Saturated Soils and Sediments,”Water Resources Research, Vol. 34, No. 11, 1998, pp. 3135-3147.
Jaffe, P.R., S.Wang, P. Kallin, S.L. Smith, “Simulating the Dynamics of Arsenic in Saturated Porous Media:  Differences in Fate and Transport between Freshwater Sediments, Wetland Sediments, and Groundwater Environments,”  in preparation.
 

Project Title:  The Effect of Surfactants on Bacterial Transport in Porous Media.

Principal Investigator(s): Peter R. Jaffé

Source of Funding:  NSF

Project Summary:  The introduction of surfactants to groundwater has the potential to significantly enhance the transport of bacteria through porous media.  This enhanced transport has implications for environmental applications, such as facilitating the introduction of acclimated bacteria or reducing biofouling at an injection well.  Furthermore, for public health considerations, surfactants found in common industrial applications and consumer goods have the potential to increase the transport of pathogenic bacteria from waste streams and septic systems into groundwater aquifers.  Unfortunately, there are no quantitative tools to determine the effects of surfactants on bacterial transport through aquifers.  The goal of this research is to provide a fundamental understanding and predictive capability on how surfactants affect the transport of bacterial through porous media.

The results of this project will provide a means of predicting the transport of bacteria through porous media based on surfactant properties.  This predictive capability will allow further development of surfactant-enhanced groundwater remediation systems, including methods to reduce bacterial soil clogging during in situ bioremediation and to allow introduction of acclimated bacteria into a contaminant plume.  This predictive capability will also allow assessment of current policies regarding surfactant concentrations in ground and waste waters in terms of transport of pathogenic microorganisms from waste streams and septic tanks into potable groundwater supplies.

Relevant Publications:
Brown, D.G., J.R. Stencel, and P.R. Jaffé, “Bacteria transport in sand column experiments: effect of media preparation,” presented at the 1999 International Symposium on Subsurface Microbiology, Vail, CO, August 22-27, 1999.
Brown, D.G. and P.R. Jaffé, “Effects of surfactants on bacterial transport through a porous media,” presented at the 5th International In Situ and On-Site Bioremediation Symposium, San Diego, April 19-22, 1999.
Brown, D.G., J.R. Stencel, and P.R. Jaffé, “Porous media preparation for bacteria filtration experiments using sand columns,” presented at the New Jersey American Water Works Association Annual Conference, Atlantic City, March 24-25, 1999.  Received Paper Award.
Brown, D.G., J.R. Stencel, and P.R. Jaffé, “Bacteria filtration experiments: Effects of sand sieving,” in preparation.
Brown, D.G. and P.R. Jaffé, “Effects of non-ionic surfactants on bacteria hydrophobicity,” in preparation.
Brown, D.G. and P.R. Jaffé, “Surfactant-enhanced bacterial transport: Effect of surfactant structure and concentration,” in preparation.
Brown, D.G. and P.R. Jaffé, “Relationship between bacterial cell UV/Visible absorbance and size in the presence of non-ionic surfactants,” in preparation.
Brown, D.G. and P.R. Jaffé, “Determining optimal regimes for surfactant-enhanced bioaugmentation,” in preparation.
 

Project Title: Trace Metal Contamination of Ground and Surface Water from Crude Oil Spills

Principal Investigator(s):  Peter R. Jaffé

Source of Funding: Theresa Heinz Foundation  (Partial Support for Graduate Student)

Project Summary:
This research is addressing the partitioning of trace metals between the oil phase and water and between water and soil which are required to assess the potential for ground and surface water contamination.  We have determined that the metals do not leach from the oil in any significant fraction as free ions, whereas our results indicate that the metals may have the ability to dissolve into the water in a complexed form, perhaps as porphyrins, and exceed drinking water standards.  This would indicate that certain types of crude oil involved in large spills could be categorized as posing a risk of contamination by trace metals, given that curent standards do not distinguish between complexed and free trace metals.
 
Relevant Publications:
Cantu, R., R. Czernuszewicz, J.R. Stencel, and P.R. Jaffé, “Surfactant Enhanced Partitioning of Nickel and Vanadium Dexophylloerythroporphyrins from Crude Oil into Water and Their Analysis Using Surface-Enhanced Resonance Raman Spectroscopy,” Environmental Science and Technology, in press.
Stencel, J.R. and P.J. Jaffe, “Trace Metal Analysis using Ion Chromatography in Water Partitioned from Crude-Oil Spills,” First International Conference on Oil and Hydrocarbon Spills, Modelling, Analysis and Control, Southampton, UK, July 29-31, 1998, Computational Mechanics Publications, Editors, R.Garcia Martinez and C.A. Brebbia, pp. 223-230 (ISBN 183125261).