Heavy Metal Content and Source-Receptor Reconciliation of Ambient PM_(2.5) Near a Coal-Fired Institutional Boiler

摘要

Ambient SO2 and PM_(2.5) aerosol samples were collected at three sites near a coal-fired institutional boiler at Clemson University during January and June of 2001. PM_(2.5) mass concentrations averaged 12.2 mug/m~3 in January and 21.2 mug/m~3 in June, with an overall average of 16.7 mug/m~3. Chemical characterization of the samples identified an average of 99%) of the fine particulate matter collected in January and 96%) in June. Organic carbon compounds made up approximately 49%) of the PM_(2.5) mass in January and 44%) in June, with sulfate contributing an average of 21%) of the PM_(2.5) mass in January and 33%) in June. Individual heavy metal concentrations were low, on the order of 0.01-0.14 mug/m~3, and total heavy metals on average contributed 0.3%) of the fine aerosol mass. Source-receptor reconciliation was completed for the fine aerosol using a chemical mass balance model, CMB8. In January, approximately 105%) of the measured mass was accounted for, and the major sources were soil dust, ammonium sulfate, ammonium nitrate, and a composite source of organic compounds. In June, an average of 80%) of the measured mass was accounted for, and the major sources were the same as in January, except that the contribution of ammonium nitrate was negligible. Comparisons between wind patterns and SO2, particulate matter, and heavy metal concentrations suggest that the evidence collected does not conclusively show a connection between boiler emissions and aerosol component concentrations at the sites sampled.