| Description |
The objective of this research is to assess the feasibility of a cold
water and Arctic marine oil spill countermeasure strategy based on the
stimulation of Oil-Mineral–Aggregate (OMA) formation in the presence of a chemical dispersant.
Evaluations will be conducted on both laboratory and wave tank systems
under controlled conditions to evaluate the potential effectiveness of
treatment of oil spills from shipboard and rig operations. Mathematical
models will be developed from the data to assess the environmental risks
of the proposed operational strategy and the effectiveness as a means to
provide guidance for field operations. The program aims to study the
applicability of combining a dispersant and common fine mineral
application to treat oil slicks in low energy regimes that are typical
in cold water and the Arctic. Our hypothesis is that this combined
treatment process would enhance the stability of the oil dispersion and
to reduce its toxicity. The fine minerals considered in this study are
readily available at oil field sites since they are common components
used in the formulation of drilling mud mixtures. The final aim of this
study is to develop new practical strategies for the use of dispersant
in low mixing energy and sensitive environments, including the Arctic.
Tasks: This research will include multiple levels of effort:
- Laboratory bench-scale experiments
- Meso-scale wave tank tests
- Toxicity and persistence evaluation of the chemically dispersed
OMA (CDOMA)
- Model simulation and analysis of the environmental risks
involved in terms of the proposed novel treatment response
technology.
To advance the research and development of this novel clean-up
technology, laboratory studies on the surface physicochemical
characteristics of oil and mineral fines in cold and icy waters, and
their interactions, are needed to clarify the factors that may influence
the oil dispersion effectiveness. The effects of the treatment factors
such as the chemical dispersant and mineral fines used, the mixing
energy levels generated during the initial breaking up stage and the
following dispersion stage, and other environmental factors such as the
seawater temperature, salinity, and dilution factor on the break up of
oil slicks into oil droplets as well as the subsequent stability of the
dispersed droplets in the water column will be investigated.
Meso-scale wave tank studies will be conducted on surface release of
oil under controlled manners to investigate the potential effectiveness
for the treatment of spills with natural mixing energy including the
initial rapid mixing stage followed by relatively low mixing energy in
the water column. Enhanced mechanical mixing energy such as what is
generated by propeller wash by comparing the break up kinetics and the
subsequent stability of dispersed oil droplets in the water column
subject to dilution through the current flow in the flow-through wave
tank will be considered.
The toxicity of the dispersed oil to selected zooplankton or fish
species by chemically dispersed OMA, and the long-term fate of these
oil-containing particles in water and sediments will be evaluated.
This task will model the transport of OMA by employing a new modeling
system which overcomes the limitations of the previous study. The
hydrodynamics will be modeled using a combined wave-current system which
simulates physical phenomena such as wave growth by action of wind,
non-linear wave-wave interaction, dissipation by white-capping,
dissipation by wave breaking, dissipation due to bottom friction,
refraction due to depth variations, and wave-current interaction. The
effect of waves on the flow field is taken into account by the radiation
stress gradients. The flow field generated by the hydrodynamic model
will then be introduced to a fate/transport model system to simulate the
transport of OMA. |
