Published: July 20, 2010

Environmental engineering faculty and students at the University of Colorado at Boulder are launching a study this month to determine the environmental fate of chemical dispersants being used in the Gulf oil spill cleanup.

Professor and water treatment expert Karl Linden will lead the one-year study, which is funded by an $82,319 RAPID-response grant from the National Science Foundation. Linden will work with Assistant Professor Fernando Rosario-Ortiz, who brings additional expertise in environmental chemistry and oxidation processes.

"Dispersants are designed to break up large globules of oil into smaller droplets that enhance biodegradation," Linden said. "However, the use of dispersants is being carried out in ways never envisioned."

Dispersants are being sprayed onto the ocean in larger quantities than ever before and injected deep underwater at the source of the oil leak, a new practice with unknown consequences, according to Linden.

The investigations will focus on Corexit, a proprietary chemical being used by BP, and on photochemical degradation -- driven by sunlight -- which is believed to be an important mechanism in the breakdown of the dispersant.

"Our research will focus on how efficient sunlight-driven processes are at degrading these compounds," Rosario-Ortiz said. "This represents a significant challenge based on the chemical complexity of these dispersants, and the different environmental factors that will interfere with these processes."

The team plans to travel to the Gulf area in late August to obtain water samples and coordinate with other studies in the area. Prior to that, the researchers will develop an analytical method to monitor the chemical constituents in the dispersant, and investigate fundamentals of the dispersant's decay in the laboratory using model ocean water and a solar simulator.

At the conclusion of the study, the team will model and estimate the half-life of identifiable chemicals in the dispersant based on sunlight conditions experienced in the Gulf of Mexico and predict their photochemical fate.

Linden and Rosario-Ortiz also plan to integrate their activities and findings into their fall undergraduate and graduate classes on environmental engineering and water chemistry.