1. Mercury Emission Ratios from Coal-Fired Power Plants in the Southeastern United States during NOMADSS.
- Author
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Ambrose JL, Gratz LE, Jaffe DA, Campos T, Flocke FM, Knapp DJ, Stechman DM, Stell M, Weinheimer AJ, Cantrell CA, and Mauldin RL 3rd
- Subjects
- Air Pollutants analysis, Atmosphere chemistry, Carbon Dioxide analysis, Linear Models, Southeastern United States, Sulfur Dioxide analysis, Aerosols analysis, Coal analysis, Mercury analysis, Nitrogen analysis, Oxidants chemistry, Power Plants
- Abstract
We use measurements made onboard the National Science Foundation's C-130 research aircraft during the 2013 Nitrogen, Oxidants, Mercury, and Aerosol Distributions, Sources, and Sinks (NOMADSS) experiment to examine total Hg (THg) emission ratios (EmRs) for six coal-fired power plants (CFPPs) in the southeastern U.S. We compare observed enhancement ratios (ERs) with EmRs calculated using Hg emissions data from two inventories: the National Emissions Inventory (NEI) and the Toxics Release Inventory (TRI). For four CFPPs, our measured ERs are strongly correlated with EmRs based on the 2011 NEI (r(2) = 0.97), although the inventory data exhibit a -39% low bias. Our measurements agree best (to within ±32%) with the NEI Hg data when the latter were derived from on-site emissions measurements. Conversely, the NEI underestimates by approximately 1 order of magnitude the ERs we measured for one previously untested CFPP. Measured ERs are uncorrelated with values based on the 2013 TRI, which also tends to be biased low. Our results suggest that the Hg inventories can be improved by targeting CFPPs for which the NEI- and TRI-based EmRs have significant disagreements. We recommend that future versions of the Hg inventories should provide greater traceability and uncertainty estimates.
- Published
- 2015
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