title: Studying the fate of non-volatile organic compounds in a commercial plasma air purifier.
abstract: Degradation of non-volatile organic compounds-environmental toxins (methyltriclosane and phenanthrene), bovine serum albumin, as well as bioparticles (Legionella pneumophila, Bacillus subtilis, and Bacillus anthracis)-in a commercially available plasma air purifier based on a cold plasma was studied in detail, focusing on its efficiency and on the resulting degradation products. This system is capable of handling air flow velocities of up to 3.0m s(-1) (3200Lmin(-1)), much higher than other plasma-based reactors described in the literature, which generally are limited to air flow rates below 10Lmin(-1). Mass balance studies consistently indicated a reduction in concentration of the compounds/particles after passage through the plasma air purifier, 31% for phenanthrene, 17% for methyltriclosane, and 80% for bovine serum albumin. L. pneumophila did not survive passage through the plasma air purifier, and cell counts of aerosolized spores of B. subtilis and B. anthracis were reduced by 26- and 15-fold, depending on whether it was run at 10Hz or 50Hz, respectively. However rather than chemical degradation, deposition on the inner surfaces of the plasma air purifier occured. Our interpretation is that putative "degradation" efficiencies were largely due to electrostatic precipitation rather than to decomposition into smaller molecules.
authors.affiliation: ETH Zürich, Department of Chemistry and Applied Biosciences, CH-8093 Zürich, Switzerland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schmid
authors.forename: Cornelia
authors.initials: C
authors.lastname: Seiler
authors.forename: Andreas C
authors.initials: AC
authors.lastname: Gerecke
authors.forename: Herbert
authors.initials: H
authors.lastname: Hächler
authors.forename: Hubert
authors.initials: H
authors.lastname: Hilbi
authors.forename: Joachim
authors.initials: J
authors.lastname: Frey
authors.forename: Simon
authors.initials: S
authors.lastname: Weidmann
authors.forename: Lukas
authors.initials: L
authors.lastname: Meier
authors.forename: Christian
authors.initials: C
authors.lastname: Berchtold
authors.forename: Renato
authors.initials: R
authors.lastname: Zenobi
mesh_terms: D061808:Air Filters; D000393:Air Pollutants / Q000737:chemistry*; D000397:Air Pollution / Q000517:prevention & control; D001408:Bacillus anthracis; D001412:Bacillus subtilis; D003300:Copper / Q000737:chemistry; D004566:Electrodes; D016952:Legionella pneumophila; D010616:Phenanthrenes / Q000737:chemistry*; D058626:Plasma Gases; D012710:Serum Albumin, Bovine; D013171:Spores, Bacterial; D014260:Triclosan / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: D000393:Air Pollutants; D010616:Phenanthrenes; D058626:Plasma Gases; D012710:Serum Albumin, Bovine; C031181:phenanthrene; D014260:Triclosan; C502486:methyl triclosan; D003300:Copper