Waste gas cleaning for road tunnels and underground car parks with carboxidotrophic mixed population

Motor vehicle emissions contribute significantly to the local air pollution problem near road tunnels and underground car parks. The most unhealthy components of the waste gas are carbon monoxide (CO), nitrogen oxides (NOx) nitric oxide (NO), and nitrogen dioxide (NO2). Recently physical and chemical purification methods for road tunnel waste gas have been tested, but no appropriate purification system has been developed yet. The application of a biological treatment system is primarily based upon the microbial degradability of the compounds in the waste gas. A pilot plant of a microbiological purification system was presented. The study on the microbiological degradation of emissions compounds was focused on carbon monoxide because aerobic and anaerobic bacteria oxidize CO, and using the CO2 released during this process as carbon source for the. Bacteria which grow with CO at the expense of energy released during the oxidation are characterized as carboxidotrophs. Nitrification, the oxidation of reduced nitrogen compounds and denitrification, the reductions of oxidized nitrogen compounds are two of the dominant driving forces in the microbiological nitrogen metabolism. The major recent advance has been to establish that nitric oxide is an intermediate in the denitrification pathway. Pure and mixed cultures have been proved to eliminate NO from waste gas by aerobic. Potential microorganisms for aerobic NO consumption are autotrophic...(this text has been cut automatically)