Emissions of gaseous pollutants from laboratory-basedfires of vegetationfromfive common vegetation types in Western Australia

Özet

This study investigated emission factors (EFs) for CO2, CO, NO and carbonyls from laboratory-based combustionoffive typical vegetation types of Western Australia. A range of combustion conditions was obtained by con-trolling the vegetation moisture content and airflow rate. CO2, CO and NO were measured using a multi-gasmonitor MultiRAE. Six carbonyls were collected using 2,4-DNPH sorbent tubes and analysed using HPLC-UV.Burns of woodland (Banksia) and forest (Jarrah) had significantly higher EFCO, with lower modified com-bustion efficiency (MCE) than those of tropical grass (Spinifex). Temperate grass (Veldt)fires had lower EFCO2and higher EFCOand EFcarbonyls, and a much lower MCE than those of the tropical grassfires. EFNOwere similarfor woodland, forest and tropical grass but large differences in EFNOwere observed for Spinifex and Veldt grass.Formaldehyde was the most abundant carbonyl emitted.Combustion conditions influenced the EFcarbonylswith larger EFs from burns with higher fuel moisture con-tents and/or at higherflow rates. Functions to extrapolate EFs for infrequently measured carbonyls (acet-aldehyde, acetone and propionaldehyde) from EFformaldehydewere developed. The EFCO2and EFCOwere similar tovalues reported fromfield measurements for similar ecosystems in Australia, indicating the applicability of theselaboratory-based results. EFs for other gases differed to those reported from bushfires in other parts of the worldsuggesting that to improve prediction of bushfire emissions and impacts in Australia, EFs of allfire-proneAustralian vegetation types should be determined, particularly for those in close proximity to densely populatedareas