Engineered Bioreactors,Dependable and Affordable Oxidation

摘要

A decade ago,biofilters installed in the United States for air pollution control failed to perform at levels acceptable to regulatory agencies.This was a surprising reality considering the large number of similar units being used in Europe(largely for odor control where objectionable emissions are only a few parts per million).Problems included intolerance of the microbes to changes in concentration or species of organic feed,inability to optimize climatological conditions for the microbe"workers,"and extended time required to replenish a damaged microbial community and the instability and air channeling that occurred in compost beds.Today's bioreactor systems bear scant resemblance to the stadium-size units of yesteryear.Improvements have been made in air distribution and moisture control as well as the substrates on which the microbial community propagates.These improvements have resulted in use of robust and mixed microbic populations that are greatly tolerant of process changes that had previously proven lethal.Although comparable in capital cost with traditional regenerative thermal oxidizers,the sustainability,slight savings in electrical power and overwhelming savings in petroleum-based fuel favorably positions bioreactors not only for growth in this country but they will be an overwhelming choice for air pollution control in fuel-expensive,developing countries.