Formation of artefacts while sampling emissions of PCDD/PCDF from open burning of biomass
| Autor: | Carly Meyer, R. R. Black, Jochen F. Mueller, Alan Yates, L. Van Zweiten |
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| Rok vydání: | 2011 |
| Předmět: |
Pollution
Environmental Engineering Polychlorinated Dibenzodioxins Health Toxicology and Mutagenesis media_common.quotation_subject Polychlorinated dibenzodioxins Lowest temperature recorded on Earth Combustion Fires Trees chemistry.chemical_compound Smoke Environmental Chemistry Biomass media_common Benzofurans geography Air Pollutants geography.geographical_feature_category Public Health Environmental and Occupational Health General Medicine General Chemistry Dibenzofurans Polychlorinated Inlet Congener chemistry Environmental chemistry Polychlorinated dibenzofurans |
| Zdroj: | Chemosphere. 88(3) |
| ISSN: | 1879-1298 |
| Popis: | Emission factors for PCDD/PCDF determined from open combustion are used to estimate national emission budgets; therefore, it is important to have confidence in their accuracy. It has been suspected that artefacts may form due to the presence of hot metal surfaces of sampling equipment, thus skewing emission factors. In this study, emissions of PCDD/PCDF from open burning of forest biomass over a brick hearth were sampled. Five experiments were carried out using a portable sampler. Experiments were designed where the key variable, sample hood and inlet temperatures were manipulated. Other variables such as fuel origin, type and density were consistent. The measured concentration of PCDD/PCDF in the smoke samples ranged from 0.01 mu g TEQ (t fuel)(-1) at the lowest maximum hood temperature (185 degrees C) to 15 mu g TEQ (t fuel)(-1) at the highest maximum hood temperature (598 degrees C). when hood inlet temperatures exceeded 400 degrees C emission factors were significantly elevated and this is attributed to the formation of artefacts that can cause the over estimation of emission factors. The increase in hood temperature also resulted in a change in the PCDD/PCDF congener and homologue profile of the emissions. For example at the lowest temperature (Fire 1) the PCDD/PCDF ratio measured was 50:1, whereas at the highest temperature (Fire 5) this ratio was about 0.53:1. When the sampler hood and inlet temperatures were kept in the normal operating range of |
| Databáze: | OpenAIRE |
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