urban and rural sources of particulate matter
TRANSCRIPT
Urban and Rural Sources of Particulate Matter
John Wenger
Centre for Research into Atmospheric ChemistryEnvironmental Research Institute
University College CorkIreland
Email: [email protected] web: http://www.ucc.ie/en/crac/
Outline
• Properties of Particulate Matter (PM)
• Linking chemical composition and sources of PM
• Case Studies- Cork City- Killarney
• Summary and Perspectives
Particulate MatterPM10 - Particulate Matter with diameter less than 10 microns
PM2.5 - Particulate Matter with diameter less than 2.5 microns
All Shapes and Sizes
• Large number of particles < 0.1 microns• Majority of mass in range 0.1-10 microns
Natural AnthropogenicPrimary Sources
• Formation and growth of particles in the atmosphere
• Ammonium, sulfate, nitrate, secondary organic aerosol
Gas +scavenging
Particle Particle
Particle Particle+coagulation
Particle
Gas Gas+nucleation
Particle
Gas condensationParticle
Secondary Sources
Fine fraction (PM2.5) Coarse fraction (PM2.5-PM10)
• Approximate composition of PM in Ireland determined by off-line analysis of filter samples
Chemical Composition
Elemental andOrganic CarbonSulphate
Nitrate
Ammonium
Chloride
Insoluble minerals
Na, K, Mg, Ca
Chemical species SourcesElemental/Black Carbon (EC or BC)
Fuel combustion (automobiles,industry, coal/wood burning)
Organic Carbon Fuel combustion, secondary organic aerosols from VOC oxidation processes
Nitrate / Sulfate Gas-particle conversion of NO2 / SO2produced from combustion processes
Ammonium Gas-particle conversion of NH3produced from agriculture
Chloride Sea sprayMinerals (Oxides of Ca, Mg, Si, Al, Fe)
Resuspension of dust/soil
Metals (K, V and Ni, Pb, Zn, Cd, Hg etc.)
Industry, combustion, often specific sources
Linking Composition and Sources of PM
Reducing PM levelsWe need to know AND quantify the sources
• How much PM is from traffic?• How much PM is from solid fuel burning?• How much PM is from other sources?• How do the emissions from these sources vary
during the day and by season?
Detailed measurements of the PM are required
• Size, concentration and chemical composition at a HIGH-TIME resolution
• Source Apportionment Modelling
Case Study: Cork Harbour
• Long-term (1 year) monitoring campaigns
• Intensive (1 month) measurement campaigns
XBB B
Tivoli Docks August 2008 and February 2009
Intensive Measurement Campaign
Healy et al., Atmospheric Chemistry and Physics 2010
Tivoli Docks August 2008 and February 2009
Intensive Measurement Campaign
A range of state-of-the-art instruments deployed for On-line monitoring of particle mass, size, number and chemical composition in real-time
Aerosol Time-of-Flight Mass Spectrometer• Detects elemental
carbon, organic carbon, metals, inorganic ions in single particles
• Provides size-resolved chemical composition(0.1-3.0 micron)
• Operates in real-time → big advantage over filter collection and off-line analysis approach
Sea-Salt Particle Mass Spectrum (Na and Cl are markers of interest)
Biomass Burning Particle Mass Spectrum (K is major marker for biomass)
Single Particle Mass Spectra
Sources in Cork Harbour: 3 Vehicular Traffic
0
500
1000
1500
2000
2500
ATO
FMS
coun
ts (h
-1)
Time
Ca-traffic EC-traffic EC-phos
Sources in Cork Harbour: Vehicular Traffic
Healy et al., Atmospheric Chemistry and Physics 2010
0
50
100
150
200
250
0
100
200
300
400
500
600
700
800
ATOFM
S counts (h- 1)ATO
FMS
coun
ts (h
-1)
Time
coal peat wood
Sources in Cork Harbour: Solid Fuel Combustion
Healy et al., Atmospheric Chemistry and Physics 2010
• State-of-the-art analytical techniques used to apportion PM mass
Source Apportionment of PM
Healy et al., Atmospheric Chemistry and Physics, 2010
PM2.5average (µg/m3)
Solid FuelBurning
%
Traffic %
Other Local
Sources %
Regional Sources
%
August 2008
9.7 5 23 24 26
February 2009
16.2 50 19 21 10
Kourtchev et al., Science of the Total Environment, 2011
Dall’Osto et al., Atmospheric Chemistry and Physics, 2013
Extent of Bituminous Coal Ban 2015
• What is the contribution of residential solid fuel burningto PM levels in towns where the Ban on Bituminous Coalis not in place?
The Burning Question
What is the contribution of each fuel type?
Sod Peat (Turf)
“Smokeless” Coal
Wood
Bituminous (Smoky) Coal
Peat Briquettes
Source Apportionment of Particulate Matter in
Urban and Rural Residential Areas of Ireland
(SAPPHIRE)
1 April 2014 – 31 March 2016
http://www.ucc.ie/en/crac/research/sapphire/
• Outside the Smoky CoalBan Area (pop. < 15,000)
• No natural gas supply
• High usage of solid fuels(coal, peat/turf & wood)
Monitoring Locations
• Killarney, Co. Kerry (Nov & Dec 2014)• Enniscorthy, Co. Wexford (Jan & Feb 2015)
K
E
• Site is located on the western side of the town, in the grounds of the Community Hospital in a residential area
Monitoring Location: Killarney
• Site is located on the western side of the town, in the grounds of the Community Hospital in a residential area
Monitoring Location: Killarney
TEOM
PM2.5 mass concentration
• PM2.5 up to 10 times higher during evening hours
PM2.5 mass concentration
• Strong diurnal pattern
Aerosol Time-of-Flight Mass Spectrometer• Detects elemental
carbon, organic carbon, metals, inorganic ions in single particles
• Provides size-resolved chemical composition(0.1-3.0 micron)
• Operates in real-time → big advantage over filter collection and off-line analysis approach
PEAT
PEAT
WOOD
COAL
COAL
ECSulfate
Potassium
Assigned on the basis of combustion experiments COAL → EC & some potassium, sulfate dominates negative spectraPEAT → EC & OC fragments, some potassiumWOOD → Potassium dominates positive spectra
EC
OC
WOOD
Mass Spectra: Solid Fuel Combustion
SEA SALT
TRAFFIC
AMINE/AMMONIUM
NaCl
NaCl2Na2Cl3 Sea salt characteristics:
→ sodium & chloride peaks, no EC
Traffic characteristics: → calcium & phosphate (lubricating oil), some EC
Phosphate
Calcium
Ammonium/amine characteristics:→ ammonium, trimethylamine, OC, large sulfate peak in negative spectra
Ammonium
Mass Spectra: Other Particle Types
Transportedsea salt
ATOFMS Particle Number
• Low wind speed – local emissions dominate• High wind speed – regional sources dominate
Particles from solid fuel burning80% of PM2.5
Particle Numbers
Particles from solid fuel burning77% of PM2.5
Particle Mass
ATOFMS: Source Contribution to PM2.5
Mass
Scaling
• Local sources account for 70-90% of PM2.5 in Cork City. Traffic accounts for ~20%; solid fuel burning 50% in winter.
• Residential solid fuel burning contributes 70-80% of PM2.5in Killarney in winter
• Similar results for Enniscorthy: also likely replicated in tens of small towns across Ireland.
• Peat, coal and wood all contribute: Extending the smoky coal ban may not be enough to deliver improvements in air quality
• No source apportionment study yet performed in Dublin!
Summary and Perspectives
Acknowledgements
John Sodeau
Ian O’Connor Eoin McGillicuddy Jovanna Arndt
Paul BuckleyStig Hellebust
Extra Slides
• Missing mass due to regional sources – organic aerosol, ammonium sulfate?
ATOFMS Particle Mass vs TEOM
Particles directly emitted from solid fuel combustion = 66% of measured PM2.5
Source contributions (% of TEOM PM2.5)
Killarney: ATOFMS Mass: Diurnal
• Particle numbers for entire sampling period averaged to 1 day → clear evening peak shows influence of solid fuel burning on total particle numbers.
• Clear evening peak in averaged mass concentration: ‒ peat (16 μg/m3)‒ wood (12 μg/m3)‒ coal (10 μg/m3)
(combined 38 μg/m3 average per night)
29/09/15 SAPPHIRE Meeting: ATOFMS (Jovanna Arndt) 37
Unidentified30%
Marine and Aged
6%Local Aged
4%Traffic3%Amines
5%
Burning52%
Preliminary Source Apportionment
• 5 factors identified• Primary emissions from
solid fuel burning = 52% of PM2.5 …….but no separation by fuel type
• PMF ME-2 using ATOFMS particle classes, EC-OC, SMPS, OPS, NOx, Aethalometer
Instrument Parameter(s) measured Temporal resolution
Aerosol time-of-flight mass spectrometer (TSI model 3800)
Single particle chemical composition (100-3000 nm)
1 min
Scanning mobility particle sizer (TSI model 3081)
Particle number concentration (10-800 nm)
3 min
Optical Particle Sizer (TSI model 3330)
Particle number concentration (300-10000 nm)
3 min
TEOM (Thermo Electron model RP 1400a)
PM2.5 mass concentration 30 min
Thermal-optical carbon analyser (Sunset Inc. model 3rd generation)
Elemental and organic carbon mass concentrations
2 hr
7-Wavelength Aethalometer(Model AE33, Magee Scientific)
Black Carbon concentration 1 min
High volume sampler (Digitel model DHA 80)
Collection of particulate matter (PM2.5)
6 hr
Key Instrumentation
TEOM Sunset ECOC
Elemental and Organic Carbon (EC/OC)
• Majority of PM2.5 during night-time pollution events is carbonaceous aerosol
Low winds – Local sources High winds – Regional sources
Influence of Meteorology
• Low wind speed – local emissions dominate• High wind speed – regional sources dominate
Enniscorthy: ATOFMS Mass: Diurnal
• Averaged ATOFMS mass concentration per day maximum = ~ 60 μg/m3
• Peak averaged daily mass concentrations: − peat (16 μg/m3)− wood (14 μg/m3)− coal (12 μg/m3)− PAH-containing (9 μg/m3)
29/09/15 SAPPHIRE Meeting: ATOFMS (Jovanna Arndt) 42
Enniscorthy: ATOFMS Mass Breakdown
29/09/15 SAPPHIRE Meeting: ATOFMS (Jovanna Arndt) 43
Solid fuel combustion particles = 89% of ATOFMS PM2.5 mass
(no comparison with TEOM yet so this % will probably decrease a bit)
PAH-containing particles associated with all three fuel types.