Researcher to determine why oil still remains from Exxon Valdez

Mar 19, 2007

Some 18 years after the Exxon Valdez ran aground and spilled nearly 11 million gallons of crude oil into Alaska's Prince William Sound, the oil continues to cause environmental problems along some of Alaska's shoreline. To help determine why the oil continues to linger long after experts predicted it would disappear, Temple University has been awarded a three-year, $1.2 million grant by the Exxon Valdez Oil Spill Trustee Council.

"Every indication tells us that the oil should have biodegraded," says Michel Boufadel, chair of Civil and Environmental Engineering in Temple's College of Engineering and the principal investigator for the grant. "But what we've seen is there are still plenty of places where the oil still exists."

According to a recent study published in the journal Environmental Science and Technology, scientists from the National Oceanic and Atmospheric Administration (NOAA), the U.S. Geological Survey and Alaskan agencies found that oil levels in the sands around the sound are much the same as they were when tests were done five years ago. The study says oil has seeped down 4 to 10 inches.

During the next two summers, Boufadel and graduate students will travel to Prince William Sound for 20 days and 50 days, respectively, to conduct field studies, take samples and try to get an understanding of the motion of the water and effects of the waves along the beaches.

"Our goal is to understand what is happening at the oil-water interface, since that is where the biodegradation of oil typically occurs," said Boufadel, an expert in oil spill remediation. "We will be examining the biodegradation from both sides of that interface — from inside and outside the oil patches." Boufadel said the researchers currently believe that micro-organisms, which would typically consume the oil, may play a key role in the oil's lack of biodegradation along the beaches.

"You would expect that over 17 to 18 years, the micro-organisms that live in water along the beach would eat the oil; that they would consume it completely," Boufadel said. "That did happen at many locations, but at these particular locations that we will be examining, there have been some limitations on that occurring."

Boufadel hypothesizes that the micro-organisms, which live in the water and need other nutrients to be able to consume the oil, may not be getting enough nitrogen, phosphorus or oxygen in order to do that. Or, he adds, a layer or sort of "skin" may have developed around the oil patches, making them impenetrable by the micro-organisms.

Boufadel also believes that environmental factors such as temperature could be inhibiting the micro-orgamisms. "There may be enough nutrients, but the temperature may be so low that these micro-organisms cannot grow fast enough to consume the oil that lingers on these particular beaches," he said.

As part of the Prince William Sound study, the research team will be using a numerical model developed by Boufadel to account simultaneously for all the factors causing the lack of biodegradation.

Source: Temple University

Explore further: Magnitude-7.2 earthquake shakes Mexican capital

add to favorites email to friend print save as pdf

Related Stories

More, bigger wildfires burning western US, study shows

17 minutes ago

Wildfires across the western United States have been getting bigger and more frequent over the last 30 years – a trend that could continue as climate change causes temperatures to rise and drought to become ...

Thinnest feasible nano-membrane produced

1 hour ago

A new nano-membrane made out of the 'super material' graphene is extremely light and breathable. Not only can this open the door to a new generation of functional waterproof clothing, but also to ultra-rapid filtration. The ...

Clean air: Fewer sources for self-cleaning

1 hour ago

Up to now, HONO, also known as nitrous acid, was considered one of the most important sources of hydroxyl radicals (OH), which are regarded as the detergent of the atmosphere, allowing the air to clean itself. ...

Recommended for you

Magnitude-7.2 earthquake shakes Mexican capital

11 hours ago

A powerful magnitude-7.2 earthquake shook central and southern Mexico on Friday, sending panicked people into the streets. Some walls cracked and fell, but there were no reports of major damage or casualties.

User comments : 0

More news stories

Magnitude-7.2 earthquake shakes Mexican capital

A powerful magnitude-7.2 earthquake shook central and southern Mexico on Friday, sending panicked people into the streets. Some walls cracked and fell, but there were no reports of major damage or casualties.

New research on Earth's carbon budget

(Phys.org) —Results from a research project involving scientists from the Desert Research Institute have generated new findings surrounding some of the unknowns of changes in climate and the degree to which ...

Impact glass stores biodata for millions of years

(Phys.org) —Bits of plant life encapsulated in molten glass by asteroid and comet impacts millions of years ago give geologists information about climate and life forms on the ancient Earth. Scientists ...