Ultrafine characterisation of emission and impact of ultrafine particulate

The aim of this project was to provide understanding of emissions and environmental impacts of fine (inferior 2.5 μm) and ultrafine (inferior 0.1 μm) particulate matter (PM) from iron and steelmaking processes enabling abatement strategies to be focused in the most appropriate areas. This is needed because of increasing evidence of adverse health effects from such particulate leading to greater legislation on air quality. A major aspect of this project was to develop a method for novel sampling using analytical techniques. Real-time in situ techniques were used including the Dekati electrical low pressure impactor (ELPI) for analysis of size-segregated particle mass and number concentrations. Aerosol mass spectrometry techniques that deliver size-resolved aerosol composition with high time-resolution were used including the TSI aerosol time-of-flight mass spectrometer (TSI ATOFMS) and new aerodyne time-of-flight aerosol mass spectrometer (ToF-AMS). The ToF-AMS was characterised in the laboratory and data processing algorithms were developed, allowing successful deployment to analyse aerosol emissions and impacts. Offline and online particle analysis based on laser-induced breakdown spectroscopy (LIBS) provided elemental analysis of size-fractionated size fractionated PM. A new analytical method was developed to measure PAHs by thermal desorption - gas chromatography - mass spectrometry (TD-GC-MS) in size-segregated PM collected with an ELPI. These techniques were applied to characterise fugitive and primary emissions, as well as ambient air samples. Source apportionment was applied to a combined TSI ATOFMS and Aerodyne ToF-AMS dataset. The processes associated with ironmaking and slag processing contributed the most to local ultrafine PM concentrations. Fine particulate was dominated by the transport of aged aerosol to the region, whereas ultrafine particulate concentrations were highly influenced by blast furnace and sintering processes.