Disputas: RuiKai Xie

Prøveforelesning

Bedømmelseskomité

Professor Jozef Pacyna, NILU & Gdansk University of Technology, Gdansk, Poland
Dr. Katarina Gårdfeldt, Chalmers Tekniska högskola / Göteborgs universitet, Sverige
Professor Walter Lund, Kjemisk institutt, Universitetet i Oslo

Leder av disputas:  Tyge Greibrokk

Veileder:  Hans Martin Seip (UiO), Grethe Wibetoe (UiO), Jan Eric Hanssen (NILU)

Sammendrag

The characterization of particulate matter (PM) provides information important to the understanding of our environment and associated health risks. In this research project, experimental methods have been developed for the collection and characterization of urban PM. Samples have been collected in three cities: Guiyang and Taiyuan in China, and Sheffield in the UK. Three technical approaches have been used: microscopic analysis, bulk sample analysis, and size-resolved analysis. The results produced add to the understanding of airborne PM in the selected areas.

1. Microscopic study: samples were collected on Teflon filters. The sampling was set to get sufficient particles distributed on the surface while avoiding overloading. Individual particles collected on the filter were analyzed by Scanning Electron Microscope with Energy-Dispersive Spectrometer (SEM-EDS). This technique was applied to two sets of samples from two cities. It was concluded that Guiyang’s particulate matter was due largely to metallurgical industries, manganese smelting in particular; and in Taiyuan it was mainly from coal combustion.

2. Bulk analysis: samples were collected on Teflon filters. The sampling duration was from a few hours to one day to get optimal loading. Samples were first digested with combination of acids and afterwards analysed by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) and inductively coupled plasma-mass spectrometry (ICP-MS). The high concentrations of arsenic and selenium, and their close correlations with lithophile elements are caused by coal combustion.

3. Size-resolved analysis: samples were collected by Electric Low Pressure Impactor (ELPI). Water soluble inorganic components were analyzed by ion chromatography (IC) and ICP-MS. It concludes that, in Sheffield airborne particulate matters, water-soluble components are a mixture of secondary aerosols and sea-salt aerosols, the extent of which depends on the origins of the air mass.

Kontaktperson

For mer informasjon, kontakt Raul Boris Briceno.