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Air Quality Impacts from Prescribed Burning Karsten Baumann, Venus Dookwah, Sangil Lee, Mei Zheng, Michael Chang, and Ted Russell Funded in part by DoD/EPA/State P2 Partnership Small Grants Program
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Clean Air Act Endangered Species Act The Conflict
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Issues on Local to Global Scales In the continental U.S. prescribed burns and forest fires contribute ~37 % to the total direct fine PM emissions of ~1 Mio t per year * * Nizich et al., EPA Report 454/R-00-002 (NTIS PB2000-108054), RTP, NC, 2000 Effects on Health Visibility Air Quality Climate Do prescribed burns reduce the risk of wild fires?
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To what extent does prescribed burning impact local and regional air quality? VOCs PM NOx O 3, SOA
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Secondary organic aerosol (SOA): Organic compounds, some highly oxygenated, residing in the aerosol phase as a function of atmospheric reactions that occur in either gas or particle phases. SOA formation mainly depends on: Emissions & forming potential of precursors aromatics (BTX, aldehydes, carbonyls) terpenes (mono-, sesqui-) other biogenics (aldehydes, alcohols) Presence of other initiating reactants O 3, OH, NO 3, sunlight, acid catalysts Mechanisms (with half hr to few hr yields): Gas-to-particle conversion/partitioning e.g. terpene oxidation Heterogeneous reactions aldehydes via hydration and polymerization, forming hemiacetal/acetal in presence of alcohols Particle-phase reactions acetal formation catalytically accelerated by particle sulfuric acid (Jang and Kamens, ES&T, 2001)
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Biomass Litter Composites MHFF… mixed hardwood (oak) forest foliage FPSP… Florida palmetto & slash pine WGLP… wiregrass & longleaf pine BUT also Primary PM Emissions from Foliar Fuel Combustion Hays, Geron et al., ES&T 36, 2281-2295, 2002
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Other Organic Carbon {SOA} 30% Wood Combustion 39% Meat Cooking 6% Vegetative Detritus 2% Gasoline Exhaust 3% Diesel Exhaust 20% Source Contributions to Organic Carbon (OC) in Ambient PM 2.5 Pensacola, FL October 1999 Measured average [PM 2.5 ] = 16.6 g m -3 [OC] = 4.6 g m -3 Zheng et al., ES&T 2002
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FAQS Observations: Regional Problem of PM 2.5 Period 2001+ 02 MAY-OCT NOV-APR
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Seasonal Differences in Diurnal Cycles: O 3 & PM 2.5 PM 2.5 Sources Near Columbus Driving Nighttime Averages in Winter 2001/02 WinterSummer
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PM 2.5 Eceedance at Columbus-OLC near Fort Benning for SE winds in Winter 2001/02 Despite regional character of PM 2.5, local PM sources on military installations dominant in winter half.
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PM 2.5 Exceedances at Columbus-OLC in Oct-Nov 2001
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Objectives and Outlook In this initial pilot study, establish understanding of the direct and indirect impact of current burn practices on sub-regional Air Quality. Lay foundation for more comprehensive and better focused Phase II Study to optimize burn practices toward minimum AQ impact. Create results of general applicability for the benefit of LMBs on other military installations in the SE-US and beyond. Learn lessons that help create and implement new revised land management strategies for the benefit of other agencies and institutions that face often times devastating wild fires in other parts of the Nation.
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OLC site upgrade Research site at Oxbow Meadows Environmental Learning Center upgraded for PM source apportionment and in situ gas phase sampling 3’ 4’ a/c 11’ 8’ Stair step 4’14’ Guy wired 8m Tower tilt down 10’ Gate 45’ x 40’ Fence N 10’ x 12’ Shelter 4 additional 20 A circuit breakers 33’ x 7’ level Platform ~ 1’ above ground 4 quadruple outlets on individual breakers
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Particle Composition Monitor “PCM” Channel 1: NH 3 Na +, K +, NH 4 +, Ca +2 Channel 2: HF, HCl, HONO, HNO 3, SO 2, HCOOH, CH 3 COOH, (COOH) 2 F -, Cl -, NO 3 -, SO 4 =, HCOO -, CH 3 COO -, C 2 O 4 = Channel 3: EC, OC, WSOC, “SVOC” Additional higher resolution CO, NO, NOy, O 3, PM-mass, and basic meteorology
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High-Vol Sampling and GC/MS Analyses Quantification of >100 Particle-phase Organic Compounds n-alkanes, branched alkanes, cycloalkanes n-alkanoic acids, n-alkenoic acids alkanedioic acids PAHs, oxy-PAHs retene steranes hopanes resin acids pimaric acid abietic acid sandaracopimaric acid aromatic acids levoglucosan POC
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Canister Sampling and GC/FID Detection of Volatile Organic Compounds VOC Collaborating with Prof. Don Blake, UC Irvine, CA 92697 http://fsr10.ps.uci.edu/GROUP/group.html C 2 -C 6 n-alkanes, alkenes, branched alkenes, alkynes isoprene Cyclic compounds monoterpenes ( -, -pinene) Aromatics, organic nitrates, halogenated species methylchloride Quantification of >60 compounds, incl. CO 2 for “fire” samples
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OLC Preliminary PM 2.5 Mass & Composition No-Burn Background 937 acres 1256 acres 3770 acres 4006 acres JanuaryApril 2003
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Preliminary Results March 2003 Progressively increasing fine PM mass and organics fraction correlate with increased temperature, solar radiation, and O 3, indicating increased oxidizing potential, hence formation of SOA.
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Preliminary POC Results: February 2003
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Still to do Evaluate regional PM from previous years relative to regional burn activity and precipitation Collect few more PCM samples into summer Analyze VOC samples Analyze POC High-Volume samples QA/QC all met, gas and PM data Do source apportionment for select samples Integrate ECMI met data from Ft Benning Merge all AQ data with fuel data Evaluate fuel-type – AQ relationship Prepare data for model integration Develop strategy for phase II
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For more information Dr. Karsten Baumann (PI) kb@eas.gatech.edu Dr. Mei Zheng mzheng@eas.gatech.edu Dr. Michael Chang chang@eas.gatech.edu Dr. Ted Russell trussell@ce.gatech.edu Find this presentation as 030520 RWCA Seattle in ppt-format at http://arec.gatech.edu/Presentations
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Acknowledgement Collaborators and Contributors CSU-OLC: Jill Whiting, Jim Trostle, site operators Becky Champion, director, “courier” Ft Benning:Polly Gustafson, EMD, reporting to J Brent Jack Greenlee, LMB, reporting to R Larimore Hugh Westbury, SERDP, contractor, reporting to D Price, US Army, Vicksburg, MS Ft Gordon:Allen Braswell, ENRMO, reporting to S Willard Augusta RP:Shari Mendrick, Col.Cty.Eng.Dept., Evans, GA
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Supplementary Material
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Progressively Increasing PM 2.5 Mass & %-Organics
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Gas-phase Emissions from Biomass Burning From laboratory combustion experiments by Lobert et al. [1990], published by Crutzen PJ and MO Andreae, Biomass burning in the tropics: impact on atmospheric chemistry and biogeochemical cycles, Science 250, 1669-1678, 1990. CO 2, NO x, SO 2, N 2 O, CH 3 Cl ( not measured ) mainly during flaming, CO, Nitriles (HCN, CH 3 CN), HC mainly during smoldering. Emission ratios (mol/mol) averaged for entire burning process: CO/NO x ~ > 25 CO/SO 2 ~ 200 Lobert JM, DH Scharffe, WM Hao, and PJ Crutzen, Nature 346, 552-554, 1990.
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