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UB device "sterilizes" contaminated air
By ELLEN GOLDBAUM
Contributing Editor
A team of UB scientists and engineers has developed a device that in minutes, instead of months, could safely and inexpensively destroy airborne biological agents in buildings as large as the Hart Senate Office Building in Washington, D.C., which was closed for several months after anthrax was detected there in October 2001.
A scanning electron microscope (SEM) image (top) shows a sample teeming with viable Bg spores; bottom SEM image shows dead residue of spores after passing through the BioBlower™ at 250 degrees C.
The device, called the BioBlower™, has immediate homeland-security applications, with the potential to eradicate a wide range of biological pathogens, such as anthrax, smallpox, SARS, influenza, tuberculosis and other toxic airborne species.
It destroys pathogens by rapidly heating contaminated air and could be employed either as a portable air-purification unit for first responders at the site of a biological attack or installed as a permanent part of a building's air-handling system to be activated immediately as soon as biological toxins are detected.
UB has filed for a provisional patent on the Bioblower™ and is negotiating a licensing arrangement with B3, a Buffalo company that its developers have formed to commercialize it.
In addition to homeland-security applications, the BioBlower™ also could provide a continuous clean air supply in hospitals, as well as military command centers and other battlefield facilities.
"The BioBlower™ destroys airborne biological agents essentially by sterilizing the air," said Jim Garvey, professor in the Department of Chemistry in the College of Arts and Sciences and a co-inventor of BioBlower™. The other co-inventors are John Lordi, research professor, James D. Felske, professor, and Joseph C. Mollendorf, professor, all in the Department of Mechanical and Aerospace Engineering in the School of Engineering and Applied Sciences.
Garvey noted that the invention represents a quantum leap ahead of the current conventional technology, HEPA (High-Efficiency Particulate Air) paper filters, which are used to trap large airborne spores and need to be changed frequently, stored carefully and subsequently destroyed.
"With our device, there are no filters to change and very minimal maintenance," said Garvey. "The BioBlower™ indiscriminately destroys all airborne biotoxins via the extreme heating of the gas."
In a series of recent tests performed by scientists in the Department of Microbiology and Immunology and the Calspan-UB Research Center (CUBRC), the BioBlower™ successfully destroyed more than 99.9 percent of aerosolized spores of a benign anthrax simulant, Bacillus globicii (Bg).
"Bg spores are considered the gold standard for biotesting," explained Garvey. "Now that we can completely eliminate these hardy bacteria, we can kill any and all airborne biological toxins."
To conduct the tests, Richard Karalus, director of microbiology for CUBRC and senior scientist in the Department of Microbiology and Immunology, and his colleagues devised techniques to inject an aerosol of the Bg spores into the BioBlower™ and recapture them on the exhaust side to see if they were still alive.
At temperatures of 50, 100 and 150 degrees Centigrade, most of the spores came through unscathed, Garvey said.
"But above 200 degrees, in just milliseconds of exposure to that heat, we killed 99.9 percent of them in a single pass," he said.
The BioBlower™ heats the contaminated air, Garvey explained, by mechanically compressing it as it is being blown rapidly through a mechanical rotary pump.
"This recompressive process uniformly increases the temperature of the entire volume of gas, almost instantaneously," he said, adding that the same type of compressive heating occurs when a tire gets hot as it is inflated with air.
"The dramatic effect we observed is due to chemical combustion; these spores simply get burned away to ash," he said.
The BioBlower™ is well-suited to applications in hospitals and other health-care settings, where airborne infections can be a leading cause of disease and even death.
"This technology continuously cycles the air," said Garvey, "making it ideal for use in isolation wards because it will kill infectious agents in the air before they can be released outside of the isolated area."
The device also is applicable to battlefield operations, such as tents, command headquarters and enclosed armored vehicles, where a continuous supply of clean air is essential, he added.
According to its developers, the BioBlower™ is based on a modification of a Roots blower, a mechanical air-pump technology that has been in existence for more than 100 years and has been used for a range of applications—from vacuum pumps in research laboratories to superchargers for drag-racing "funny cars."
"It's a deceptively simple idea," said Lordi.
Roots blowers, he explained, consist of two rotating, stainless-steel cams that turn in opposite directions so that air is sucked in at one end and pushed out at the other end.
Lordi had been conducting research with Mollendorf and Felske on using a Roots-type mechanism to compressively heat gases.
The BioBlower™ is a modified Roots blower pump capable of extremely high gas-flow rates—up to hundreds of cubic feet per minute, Lordi explained.
"In the BioBlower™, the entire volume of air ingested by the rotary pump is rapidly compressed and heated to between 200 and 250 degrees Centigrade," he said. "Then, it's expanded and cooled before being returned—free of any biotoxins—to the area being remediated."
The UB team is seeking government and private funding to further test the BioBlower™ on viruses and other bacteria and also to modify it for destruction of chemical agents as well.
Biotesting with Bg was funded by UB's Center for Advanced Technology, which promotes development and commercialization of UB research with the support of the New York State Office of Science, Technology and Academic Research (NYSTAR).
The BioBlower™ is a direct result of collaborations between chemists in the College of Arts and Sciences, engineers in the School of Engineering and Applied Sciences, and microbiologists in the School of Medicine and Biomedical Sciences.