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Capabilities of a 2,5 cubic meters smog chamber for the investigation of the photodegradation of chemicals in the presence of aerosol surfaces

Möglichkeiten einer 2,5 cbm Smogkammer für die Untersuchung des Photoabbaus von Chemikalien in Gegenwart von Aerosoloberflächen
: Behnke, W.; Koch, W.; Nolting, F.; Zetzsch, C.

Troyanowsky, C.:
Air Pollutants and Plants
Weinheim: VCH Verlagsgesellschaft, 1985
ISBN: 3-527-26310-1
European Conference on Chemistry and the Environment <2, 1984, Lindau>
Fraunhofer ITA ( ITEM) ()
Adsorptionswärme; aerosol; Alkan; Aromat; Hydroxyl-Radikal; Photohalbleiter; Reaktion(heterogen); Smogkammer; Titandioxid

The construction and properties of a smog chamber designed for the study of the influence of aerosols on atmospheric reactions are described. Careful air conditioning and optimized particle diameters (0.5 mym) yield long half-lives of the aerosol mass up to two days in the dark and up to 1 day in the presence of simulated sunlight. The degradation of chemicals in the presence and absence of sunlight can be investigated in the presence and absence of aerosols in order to get information about homogeneous gas phase reactions, about heterogeneous processes forming precursors of OH radicals in a photochemical smog, about direct photolysis of the layer adsorbed on the aerosols, about the transformation of NOx and of SOs into acids in the presence of humidity, about gas to particle conversion and sedimentation among other chemical and physical processes. First results on the photodegradation of a series of alkanes in the absence and presence of aerosol particles (SiO2 or TiO2) are presented. (ITA)