title: Biodegradation of VOCs from printing press air by an on-site pilot plant bioscrubber and laboratory scale continuous yeast cultures.
abstract: The volatile organic compound composition (VOCs) of printing press air was found to contain mostly ethanol, but also ethyl acetate, 1-propanol, 2-propanol, 1-methoxy-2-propanol and 3-ethoxy-1-propanol. A pilot plant bioscrubber inoculated with a mixed microbial population was constructed on-site. The bioscrubber was able to treat the polluted gas efficiently. It, however, suffered from strong wall growth and blockages in the column. The efficiencies of the pilot plant and a bioreactor is compared. The yeasts Candida guilliermondii and Saccharomyces cerevisiae known to tolerate ethanol were selected instead of mixed population to avoid the wall growth a nd blockages inthe bioreactor. The removal of the VOCs both individually and as a complex mixture was tested in a microcultivation system and in continuous chemostat cultures with and without cell recycling. The Candida yeast could use all the compounds as a carbon source while growth of S. cerevisiae was markedly slower on the methoxylated and ethoxylated propanols. Best total removal of the VOCs was 99% and achieved by C. guilliermondii. The only compound that was not totally removable in the chemostat experiment with C. guilliermondii was 1-methoxy-2-propanol. In laboratory scale the total and volumetric removal of VOCs by C. guilliermondii was more efficient compared to the pilot plant encouraging to scale up and applying the yeast bioreactor to real field conditions.
authors.affiliation: Helsinki University of Technology, Laboratory of Bioprocess Engineering, Finland. tom.granstrom@hut.fi
authors.forename: Tom
authors.initials: T
authors.lastname: Granström
authors.forename: Pia
authors.initials: P
authors.lastname: Lindberg
authors.forename: Jyri
authors.initials: J
authors.lastname: Nummela
authors.forename: Jouni
authors.initials: J
authors.lastname: Jokela
authors.forename: Matti
authors.initials: M
authors.lastname: Leisola
mesh_terms: D000395:Air Pollutants, Occupational / Q000378:metabolism*; D000397:Air Pollution / Q000517:prevention & control; D000438:Alcohols / Q000378:metabolism; D001673:Biodegradation, Environmental; D019149:Bioreactors; D004867:Equipment Design; D004952:Esters / Q000378:metabolism; D009930:Organic Chemicals / Q000378:metabolism*; D010865:Pilot Projects; D011327:Printing; D014835:Volatilization; D015003:Yeasts / Q000254:growth & development / Q000378:metabolism*
chemical_list: D000395:Air Pollutants, Occupational; D000438:Alcohols; D004952:Esters; D009930:Organic Chemicals