VATIS UPDATE Article

Scientists at the U.S. Geological Survey (USGS) have developed and patented a bioreactor to remove gaseous methyl bromide from the exhaust that results from the fumigation of shipping containers. The system makes use of specialized bacteria for efficient removal of the contaminants. Seaports all along the coasts receive thousands of shipping containers each day that are routinely fumigated with methyl bromide to prevent non-native insects and other unwanted organisms from invading the country.

The downside of this practice is that the methyl bromide (bromomethane) exhausted to the atmosphere from fumigation operations has a negative impact on the Earth’s ozone layer. In addition, methyl bromide is hazardous to human health. USGS scientists Larry Miller, Ron Oremland, and Shaun Baesman have received a patent (patent number 6,916,446) for a bioreactor that removes methyl bromide from the exhaust from fumigation operations.

The bioreactor contains a culture of specialized microorganisms (methylotrophic bacteria) that removes methyl bromide from the exhaust by oxidizing it to carbon dioxide, hydrobromic acid, and water. A 1,000-liter bioreactor is capable of removing 10 kilograms (kg) of methyl bromide in 50 hours. The development of the bioreactor is a practical application of the extensive research by these scientists on microorganisms in the natural environment that degrade methyl bromide and other methyl halides.