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:

1. Laboratory bench-scale experiments
2. Meso-scale wave tank tests
3. Toxicity and persistence evaluation of the chemically dispersed OMA (CDOMA)
4. 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.

Last Updated: 04/20/2010, 03:38 PM