National Geographic : 1993 Aug
Ohio, among others. With John Armstrong, TGI's founder, I strolled the grassy test area above the spill. Every few feet white plastic well pipes thrust above the green like cemetery markers. Some carried air down to the pollut ed aquifer. Shorter ones drew air up through the soil-the key to bioventing. "Air pumped down to the groundwater picks up the contaminants," said Dr. Arm strong. "Then vacuum pumps draw the dirt ied air back up. As the contaminants filter through the soil they are eaten by the native bacteria, which we encourage with nutrients. "Air analyzed at the surface is clean. The microbes turn the soil itself into a bioreactor." "Bioventing is slow but cheap," said Dr. Wilson. "It can reach under buildings and other surface obstructions. It should be the technology of the future." Like fuels from leaking tanks, other pollut ants are woefully common. Microbes find growing roles with each. * Paint-stripping sites: Kelly Air Force Base in San Antonio, Texas, strips old paint from C-5s-half a million pounds of pollutants a year that few landfills will accept. Other mili tary bases and commercial aircraft contribute similar noxious debris. Bacteria:Teaching Old Bugs New Tricks HIGH-TECH TUNES Microbes make the music in a set of $4,000 headphones designed by Sony Corporation, which molds bacteria-produced cellulose (facing page) into speaker diaphragms that boast superb acoustic qualities. Tireless bio logical factories, bacteria are also capable of churning out medicines, vitamins, and even plastics that biodegrade in landfills. Could microbes star as strippers? Their show hit the road at a laboratory in Utah. "Two bacteria and a fungus remove the paint," said Gail Bowers-Irons of Technical Research Associates in Salt Lake City. "We found them at an old paint landfill." She showed me a bottle holding liquid and a chunk of painted metal. The microbes were loosening paint from the metal as if peeling a banana. "Once the paint is removed, we have a bac terium that eats it," said Mrs. Bowers-Irons. "The bacterium came from a junk pile. We look for helpful bugs wherever equipment is falling apart." A pilot plant for consuming paint is scheduled to be built at Kelly Air Force Base next year.