“The concentration of detergents and other chemicals used to clean up sites contaminated by oil spills can cause environmental nightmares of their own,” says Terry Hazen, a microbial ecologist in Berkeley Lab’s Earth Sciences Division who has studied such notorious oil-spill sites as the Exxon Valdez spill into Alaska’s Prince William Sound.
“It is important to remember that oil is a biological product and can be degraded by microbes, both on and beneath the surface of the water,” Hazen says. “Some of the detergents that are typically used to clean-up spill sites are more toxic than the oil itself, in which case it would be better to leave the site alone and allow microbes to do what they do best.”
The Deepwater Horizon oil rig leased by energy giant BP that exploded on April 20, is now estimated to be disgorging some 210,000 gallons of oil a day into the Gulf of Mexico. To contain the spreading oil slick and keep it from polluting the fragile ecosystems of the Gulf coast and the Mississippi delta, clean-up crews have deployed an array of chemical dispersants, oil skimmers and booms. They have also attempted to burn off some of the surface oil. Such aggressive clean-up efforts are fraught with unintended consequences, Hazen warns. He cites as prime examples the Amoco Cadiz and the Exxon Valdez disasters.
In 1978, an oil tanker, the Amoco Cadiz, split in two about three miles off the coast of Normandy, releasing about 227,000 tons heavy crude oil that ultimately stained nearly 200 miles of coastline. The spill-site was so large that only the areas of greatest economic impact were treated with detergents. Large areas in the more remote parts of the coast went untreated.
“The untreated coastal areas were fully recovered within five years of the Amoco Cadiz spill,” says Hazen. “As for the treated areas, ecological studies show that 30 years later, those areas still have not recovered.”
In March of 1989, the oil supertanker Exxon Valdez spilled 11 million gallons of crude oil into the Prince William Sound and impacted some 1,300 miles of coastline. It remains the largest oil spill in U.S. history. A combination of detergents and bioremediation were used in the clean-up. The detergents were nutrient rich, being high in phosphorous and nitrogen compounds. In addition, as part of the bioremediation effort, fertilizers were also used to promote microbial growth. After the first year, the treated areas were dramatically cleaner, Hazen says, but after the second year no improvements were observed. Long-term prospects for the treated area are grim.
Terry Hazen is a scientist with Berkeley Lab’s Earth Sciences Division where he heads the Ecology Department and Center for Environmental Biotechnology, and co-directs the Virtual Institute for Microbial Stress and Survival.
“What happened was that we took an oligotrophic (low nutrient) environment, and added lots of nutrients to it to speed up the degradation of the oil, which we probably did,” Hazen says. “However, we upset the ecological balance of the system, which could not handle the influx of nutrients. As a result, the severe environmental damage resulting from the spill is expected to persist for decades to come.”
While improvements to detergents have been made, including some degree of biodegradability, they remain nutrient rich and in some cases more toxic to the environment than crude oil.
“From a clean-up standpoint, right now we should be using sorbents to take up as much of the oil as possible,” Hazen says. “Then we need to gauge how quickly and completely this oil can be degraded without human intervention.”
Berkeley Lab is a U.S. Department of Energy national laboratory located in Berkeley, California. It conducts unclassified scientific research and is managed by the University of California. Visit our website at http://www.lbl.gov.
A public lecture by Terry Hazen entitled “Bioremediation: The Hope and the Hype for Environmental Cleanup” can be viewed on the Berkeley Lab YouTube site at http://www.youtube.com/watch?v=MT0qY3_n1kI
For more about the research of Terry Hazen, visit the Website at http://esd.lbl.gov/about/staff/terryhazen/
Lynn Yarris | EurekAlert!
Preservation of floodplains is flood protection
27.09.2017 | Technische Universität München
Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research