This research is in response to events subsequent to an explosion on the British Petroleum (BP) Deepwater Horizon Oil Rig in the Gulf of Mexico off the coast of Louisiana. One strategy that BP is taking to stem the flow of oil toward the shoreline is the use of dispersants. Dispersants are designed to break up large globules of oil into smaller droplets that would be more amenable to biodegradation. However, the use of dispersants is being carried out in larger quantities than ever before and being injected deep underwater at the source of the oil leak. The US Environmental Protection Agency (EPA) is extremely concerned about the toxicity of the dispersant being used and issued a directive to BP ?to identify and use a less toxic and more effective dispersant from the list of EPA authorized dispersants?. This proposal was submitted to the RAPID program to provide quick response research relating to this anthropogenic disaster. The research to be performed under this RAPID proposal is to study the photochemical fate of the dispersants used in the spill clean-up effort to determine the extent to which sunlight driven processes can degrade the chemicals used. The environmental fate of the surfactants and hydrocarbons being spread into the ocean are relatively unknown. The objectives of this study are to (1) develop an analytical method to follow the decay of the dispersant (COREXIT) in the laboratory using a mass spectral fingerprint analysis; (2) Investigate the sunlight driven degradation of COREXIT in laboratory grade water and synthetic ocean waters; (3) Obtain environmental samples of water containing the dispersant and study the sunlight decay in the presence of the background water matrix and oil from the spill; and (4) Model and estimate the half life of identifiable chemicals in the dispersant, based on sunlight fluences experienced in the Gulf on the water surface.
The intellectual merit of this proposal is to develop both fundamental and applied data that will help predict the photochemical fate of dispersants discharged into the Gulf of Mexico. Fundamental data include rate constants, quantum yields, and radical reaction rates, while the applied information relates to half-life of the chemicals and long-term potential for chemical impacts.
The broader impacts for this project will focus mostly on the dissemination of results via media, public seminars and governmental agencies concerned with the environmental impacts of the oil spill. Their activities during travel to the gulf to survey the region and collect samples will be communicated using outlets such as web postings and Twitter. These tweets and Internet activity will be communicated to classes in session at University of Colorado-Boulder such as Fundamentals of Environmental Engineering in Fall and Spring 2010/11. Given the environmental significance of this disaster event and the technologies being implemented to deal with the situation, the team will use the information from the project and incorporate it into course material as part of a newly funded GK-12 by NSF at UC-Boulder. The student funded on this RAPID project will also participate in the GK-12 grant and will incorporate the results into lessons targeting the pros and cons of oil exploration and also the need for engineers in these areas. A simple experiment where an oil leak is simulated in a beaker, complete with dispersants, will also be developed as a ?hands-on? activity.
The dispersants used in the Gulf Oil spill were released into the ocean environment in unprecedented amounts. What happened to the chemicals released is of interest in this research. Specifically how sunlight impacts the decay of these chemicals was studied by carrying out experiments on the sunlight degradation of select chemicals that make up the oil dispersant COREXIT. This project involved both analytical and experimental method development in order to evaluate the oil dispersants. Experiments were conducted in lab and natural ocean waters. Three major methods were developed and these analytical methods were used to support the evaluation of the photochemical degradation of these compounds. The major findings from this research provide information in understanding of the fate of two specific components of the dispersant COREXIT. Sunlight mediated oxidation - where sunlight interactions with the ocean water form chemical oxidants that then degrade the chemicals - appears to be the major pathway of decay, resulting in decay of 90% in about 1 day. The oxidation process occurs in natural ocean waters due to interactions between photosensitizers and light, producing oxidants (likely from nitrate and natural organic matter). These results are essential for understanding the fate of these compounds in ocean water and could be applied to predictive models. Furthermore, the results can be applied in a number of fields and industries that utilize or interact with these compounds. There were several educational outreach programs that were completed in association with this project. We put on workshops involving hands-on projects that allowed students to learn about the Gulf Oil Spill and how dispersants work. Two years in a row we participated in a workshop put on by the Broadening Opportunities for Learning and Diversity Center at CU Boulder. This workshop was designed for students from lower income backgrounds that are interested in STEM programs. At two middle schools, a similar hands-on workshop was carried out. We also participated in the 16th annual Expanding Your Horizons workshop put on by the Boulder branch of the American Association of University Women and University of Colorado Boulder. This program brought middle school girls to the university for several presentations that allowed them to see science in action. The project made use of social media to report on our findings and milestones. We set up twitter accounts and used them periodically during travel to the Gulf for our research as well as to report on interesting findings and achievements. The researchers also participated in interviews on radio, print media, and television discussing our project with the general public.
