Air Quality Impacts from Prescribed Burning Air Quality Impacts from Prescribed Burning Sangil Lee 1, Karsten Baumann 2, Mei Zheng 2, Fu Wang 2 1 School

0

100

200

300

400

500

600

700

Co

ncen

trati

on

, n

g/m3

n-Alkanes Hopanes Steranes PAHs Resin scids Aromatic carboxylic acidsOther compounds Levoglucosan Branched alkanesn-alkanoic acids Alkenoic acids Alkanedioic acids

Mixing ratio enhancements above background

1.0E-02

1.0E-01

1.0E+00

1.0E+01

1.0E+02

1.0E+03

1.0E+04

1.0E+05

1.0E+06

1.0E+07

CH

4

CO

CO

2

CH

Cl3

CH

2C

l2

C2

HC

l3

C2

Cl4

CH

3C

l

CH

3B

r

Me

ON

O2

EtO

NO

2

i-P

rON

O2

n-P

rON

O2

2-B

uO

NO

2

Eth

an

e

Pro

pa

ne

i-B

uta

ne

n-B

uta

ne

i-P

en

tan

e

n-P

en

tan

e

2-M

eth

ylp

en

tan

e

3-M

eth

ylp

en

tan

e

n-H

exa

ne

n-H

ep

tan

e

n-O

cta

ne

Eth

en

e

Eth

yn

e

Pro

pe

ne

1-B

ute

ne

i-B

ute

ne

tra

ns-2

-Bu

ten

e

cis

-2-B

ute

ne

1,3

-Bu

tad

ien

e

Be

nze

ne

To

lue

ne

Eth

ylb

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ne

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p-X

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Iso

pro

pylb

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ne

Pro

pylb

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3-E

thly

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e

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thylto

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2-E

thylto

lue

ne

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pre

ne

alp

ha

-Pin

en

e

be

ta-P

ine

ne

CH

4, C

O (

pp

mv)

O

thers

(p

ptv

)

Flamming Smoldering

Air Quality Impacts from Prescribed BurningAir Quality Impacts from Prescribed BurningSangil Lee1, Karsten Baumann2, Mei Zheng2, Fu Wang2

1School of Civil and Environmental Engineering, 2School of Earth and Atmospheric SciencesGeorgia Institute of Technology, Atlanta, Georgia

ObjectiveObjectiveGuided by the Endangered Species Act (ESA), the DOI through the Fish and

Wildlife Service mandates that most army and air force bases in the South-

Eastern US use prescribed burning to maintain the health of its native long

leaf pine forest and thus protecting the habitat of the endangered red-

cockaded woodpecker. In recognition of the conflicting requirements between

the ESA and the Clean Air Act (CAA) statutes, the “Study of Air Quality

Impacts Resulting from Prescribed Burning on Military Facilities” was initiated

and sponsored by the DOA/CERL in support of the DOD Pollution prevention

Partnership.

Prescribed BurningPrescribed Burning Develops, maintains, and enhances wildlife habitat.

Protects endangered plants and animals.

Preserves and protects cultural resources and wilderness.

Minimizes potentials of catastrophic wildfires that could result from heavy

accumulations of vegetative fuels.

Air Quality Issues associated with Prescribed BurningAir Quality Issues associated with Prescribed BurningEmissions from prescribed burning are important primary sources of gases

and particulate matter (PM) to the atmosphere.

fine particles and gases are main contributor to smoke, impairing visibility.

particles less than 2.5 m are released, which are respirable.

organic compounds make a large portion of particles, which might have

potential of adverse health effects.

25%

6%

7%

2%

28%

12%

5%

3%

12%Sulfate

Nitrate

Ammonium

EC

OC

OOE

LOA

Others

UnID

Average mass = 10.4 +-2.6 g m-3

Period 20 - 22 January

Measurement Site (Oxbow Learning Center) and Prescribed Burning Site (Fort Benning) near Columbus, GAMeasurement Site (Oxbow Learning Center) and Prescribed Burning Site (Fort Benning) near Columbus, GA

18%

4%

12%

2%

35%

14%

8%

3% 4%


Period 2 - 6 February

24%

5%

3%

4%

34%

14%

3%

8%5%


Period 10 - 11 March

17%

2%

7%

2%

42%

17%

4%

8%1%


Period 24 - 27 March

26%

1%

12%

1%31%

12%

4%1%

12%


Period 13 - 17 April

30%

1%

8%

1%

27%

11%

4%1%

17%


Period 28 April - 01 May

17%

1%

8%

1%

35%

13%

4%

1%

20%


Period 28 - 31 May

Measurements of particle-phase organic compounds (POC) have been made by a

High Volume Sampler with pre-baked quartz filters. Sampled quartz filters were

extracted by organic solvent and then analyzed by Gas Chromatography/Mass

Spectrometry (GC/MS). Total 105 POCs are identified: n-alkanes (20), hopanes (10), steranes (4), polycyclic

aromatic hydrocarbons (19), resin acids (9), aromatic carboxylic acids (3), branched

alkanes (3), n-alkanoic acids (17), alkenoic acids (3), alkanedioic acids (19). Cellulose, which provides structural strength to plants, constitutes 40-50 % dry

weight of wood. Thermal decomposition of cellulose produces mainly levoglucosan,

a good marker for biomass burning. Burning conifers containing resin produce resin

acids. Samples for the February event have been analyzed so far. Levoglucosan is

dominant among organic compounds identified by GC/MS. Two biomass tracers have

very similar trend of concentrations. Their concentrations 5 hours after burning is a

factor of 2 to 5 higher than those of background and right after burning, respectively.

This increase is associated with relatively calm conditions at nighttime.The contribution of wood smoke to total organic carbon increases from 11 +- 2 %

before to 53 +- 5 % after the flaming phase of the prescribed burn, conducted ca. 28

km to the east of the sampling site. A wind shift from strong westerly to weaker

easterly component causes to impact the samples collected after 1700.

Time Series Plot of Measured Gases and Particulate MatterTime Series Plot of Measured Gases and Particulate Matter

Organic Compounds Organic Compounds of PMof PM2.52.5 and Source Apportionment from Chemical Mass Balance Approach and Source Apportionment from Chemical Mass Balance Approach

Weekly Average Diurnal Cycles of Weekly Average Diurnal Cycles of

Meteorological Parameters and Air Pollutant Concentrations in MarchMeteorological Parameters and Air Pollutant Concentrations in March

Larger differences between the daily minimum and maximum air T and RH were observed on two burn weeks

in March, indicating overall less cloud coverage, more stably stratified nocturnal BL and generally drier conditions.

An overall increasing warming trend leads to more intense atmospheric photochemical activity and higher daytime

O3 maxima. The two burn weeks were also characterized by elevated nighttime PM2.5, CO and NOy concentrations

associated with calmer conditions under weak easterly component winds. Continued emissions from smoldering

fuel of the prescribed burnings likely account for this nighttime increase, since the relatively cold plumes

(compared to daytime flaming condition) are being mixed into the shallow nocturnal boundary layer.

Non-burn week Non- burn weekBurn week Burn week

Background measurement

without prescribed burning.

Low pressure system with showers

and T-storm from 3rd to 4th. Cold

air moved into the region at early

morning of the burn day.

Highest PM2.5 event associated

with relatively calm and clear

conditions on 25th.

Decrease in temperature and PAR

plus increase in wind speed in the

wake of a front lead to decreasing

O3 maxima and PM2.5 levels.

937 acres 1256 acres 3770 acres 4067 acres 504 acres 251 acres

Build-up in PM2.5 and O3 maxima

after record rainfalls earlier in May;

strong daytime winds.

Relatively stagnant

conditions all week.

January February March April May

Increasing fractions of Unidentified

Mass (grey) with time progressing

into warmer season, indicates likely

larger OOE (turquoise) fraction,

reflecting an organic mass to

organic carbon ratio (OM/OC)

increasingly larger than 1.4 possibly

due to higher oxygenated PM.

Quantification of water-soluble OC

fraction pending!

34.4

34.2

34.0

33.8

33.6

33.4

33.2

33.0

32.8

32.6

32.4

32.2

32.0

-85.5 -85.0 -84.5 -84.0 -83.5 -83.0 -82.5 -82.0

Atlanta

FAQS measurement sites GA-EPD monitoring sites coal burning power plants point sources w/ CO:NOx > 1

20x20 km

N

E

S

W9 18

µg m-316.7

15.5Macon SBP

N

E

S

W9 18

µg m-3

Columbus OLC 16.6 19.3

N

E

S

W9 18

µg m-3

15.8 13.4 Griffin

N

E

S

W9 18

µg m-315.0

14.2Augusta RP

300

200

100

0

PA

R (

W/m

2 )

100

80

60

40

20

RH

(%

)

December

50

40

30

20

10

0PM

2.5(

g/m

3) N

O N

Oy

O3

(pp

bv

)

00:00 06:00 12:00 18:00 00:00

Time (EST)

January February March April

450

400

350

300

250

200

CO

(pp

bv

)

May 30

20

10

Air T

(°C)

3

2

1

WS

(m/s

)

June

1600

1400

1200

1000

800

600

400

200

CO

(

ppbv)

30min avgslope = 10.6 ± 0.1i-cept = 152.9 ± 2.5

R2 = 0.920

1600

1400

1200

1000

800

600

400

200

CO

(

ppbv)

120100806040200

NOy (ppbv)

y = 8x + 140 reference

December

30min avgslope = 8.5 ± 0.1i-cept = 166.4 ± 2.0

R2 = 0.876


March

30 min avgslope = 9.0 ± 0.2i-cept = 183.9 ± 2.8

R2 = 0.745


February


January


R2 = 0.778


R2 = 0.815


April


R2 = 0.653


May

30min avgSlope = 16.9 ± 0.3i-cept = 181.1 ± 1.9

R2 = 0.701


1.0

0.8

0.6

0.4

0.2

0.0

NO

/NO

y

0.00

350

300

250

200

150

100

50

0

Win

d D

irect

ion

(d

eg

N)

1.0

0.8

0.6

0.4

0.2

0.0

NO

/NO

y

1.00

00:00

06:00

12:00

18:00

00:00

Tim

e o

f D

ay (

ES

T)

Monthly Diurnal Patterns and CO/NOy RelationshipsMonthly Diurnal Patterns and CO/NOy Relationships

Dec’02

Feb’03

Jan’03

Mar’03

May’03

Jun’03

Wind Rose Plots of Major pollutantsWind Rose Plots of Major pollutants

Emission Factors (dVOC/dCO2)

1.0E-03

1.0E-02

1.0E-01

1.0E+00

1.0E+01

1.0E+02

1.0E+03

1.0E+04

CH

4

CO

CH

Cl3

CH

2C

l2

C2H

Cl3

C2C

l4

CH

3C

l

CH

3B

r

MeO

NO

2

EtO

NO

2

i-P

rON

O2

n-P

rON

O2

2-B

uO

NO

2

Eth

ane

Pro

pane

i-B

uta

ne

n-B

uta

ne

i-P

enta

ne

n-P

enta

ne

2-M

eth

ylpenta

ne

3-M

eth

ylpenta

ne

n-H

exa

ne

n-H

epta

ne

n-O

ctane

Eth

ene

Eth

yne

Pro

pene

1-B

ute

ne

i-B

ute

ne

trans-

2-B

ute

ne

cis-

2-B

ute

ne

1,3

-Buta

die

ne

Benze

ne

Tolu

ene

Eth

ylbenze

ne

m-X

ylene

p-X

ylene

o-X

ylene

Isopro

pyl

benze

ne

Pro

pyl

benze

ne

3-E

thly

tolu

ene

4-E

thyl

tolu

ene

2-E

thyl

tolu

ene

Isopre

ne

alp

ha-P

inene

beta

-Pin

eneC

H4,

CO

(p

pm

v/p

pm

v)

O

thers

(p

ptv

/pp

mv)

0.1

1.0

10.0

100.0

Sm

old

eri

ng

/Fla

mm

ing

Rati

o o

f E

mis

sio

n F

acto

rs

Flamming Smoldering Ratio (S/F)

VOC Emissions at Prescribed Burning SiteVOC Emissions at Prescribed Burning Site

0

1

2

3

4

5

6

7

02/02 00-1200 02/05 12-1700 02/05 17-2200 02/06 22-0300 02/06 03-0800 02/06 08-1300

Day, Sampling Period (mmdd hh-hhmm)

Co

nc

en

tra

tio

n, u

g/m3

Diesel exhaust Gasoline exhaust Wood combustion Vegetative detritus Other OC

Apr’03

N

E

S

W6 12

N

E

S

W2 4

N

E

S

W9 18

N

E

S

W150 300

N

E

S

W4 8

N

E

S

W6 12

N

E

S

W2 4

N

E

S

W8 16

N

E

S

W160 320

N

E

S

W6 12

N

E

S

W4 8

N

E

S

W2 4

N

E

S

W7 14

N

E

S

W180 360

N

E

S

W9 18

N

E

S

W8 16

N

E

S

W9 18

N

E

S

W200 400

N

E

S

W14 28

N

E

S

W2 4

N

E

S

W9 18

N

E

S

W170 340

N

E

S

W7 14

N

E

S

W2 4

N

E

S

W7 14

N

E

S

W2 4

N

E

S

W11 22

N

E

S

W190 380

N

E

S

W7 14

N

E

S

W6 12

N

E

S

W2 4

N

E

S

W12 24

N

E

S

W150 300

N

E

S

W4 8

N

E

S

W6 12

WD Frequency (%) WS (m/s) PM (g/m3) CO (ppbv) NOy (ppbv)

Distinct increase of PM concentration at Columbus is associated

with air masses coming from southeast during Nov-Apr, which is

the prescribed burning period.

Period 2001+ 02MAY-OCTNOV-APR

Nighttime (18:00 - 11:00)

Daytime (11:00 - 18:00)

Measurement site is

characterized by weak easterly

component flow at night, and

stronger westerly component

flow at daytime. Weak SE flow

carries pollutant emissions from

prescribed burning at military

installation during active burn

period (Dec-Apr), however, for

May & June (little burn activity)

no distinct increase of pollutants

in air masses coming from SE.

VOC sampling was conducted at different stages of

burning (i.e., pre-ignition, flaming, smoldering) and locations (i.e.,

upwind, downwind, burn unit) at prescribed burning sites for

each burning event. The collected samples were analyzed at the

University of California, Irvine, for total 47 gas species including

CO, CO2, and CH4. Mixing ratio enhancements were calculated

by subtracting mixing ratio of upwind (background) from that of

flaming or smoldering stage. As seen by higher CO2/CO ratio,

flaming is more efficient combustion than smoldering, leading to

larger mixing ratio enhancement. However, less efficient

combustion (smoldering ), which has longer duration (8-12 h)

than flaming (2-3 h), makes higher emission factors. The

prolonged emissions at higher relative rates during smoldering

potentially causes the observed increase of pollutant

concentrations at night under calm conditions in a stable

nocturnal BL.

Acknowledgement

This work was sponsored by the Department of the Army/ U.S. Army Construction Engineering Research Laboratories (CERL) via subcontract with the University of South-Carolina (USC), Grant No. DACA42-02-2-0052, in support of the DOD Pollution Prevention Partnership. The authors gratefully acknowledge the collaboration and field support received by Jill Whiting, Jim Trostle, and Becky Champion (CSU-OLC), Jack Greenlee, Hugh Westbury, Polly Gustafson, and John Brent (Ft. Benning), Frank Burch and Steven Davis (Columbus Water Works), Allen Braswell and Stephen Willard (Ft. Gordon), Venus Dookwah, Wes Younger and Michael Chang (GIT-EAS).

Background CO concentration

increases with increased

prescribed burning activities.

Peak values stay about three

months and decrease a month

after burns have largely ceased.

Background CO levels are

determined from linear CO vs

NOy regressions. Standard

errors vary between 1.5 and 2.8

ppbv. Slopes indicate mixed

influence from mobile, small

industrial and PB sources.

PB start at noon

120

140

160

180

200

220

Dec-02 Jan-03 Feb'03 Mar'03 Apr'03 May'03 June'03

Month

CO

(p

pbv)

0

2,000

4,000

6,000

8,000

10,000

12,000

Bu

rned

Acr

es

Mil Base (acr)

Surr Region (acr)

CO bkgrd (ppbv)

Impact on Regional CO BackgroundImpact on Regional CO Background

Wind shift

Documents

Air Quality Impacts from Prescribed Burning Air Quality Impacts from Prescribed Burning Sangil Lee 1, Karsten Baumann 2, Mei Zheng 2, Fu Wang 2 1 School