Atmospheric Deposition of Mercury, Trace Metals and Major Ions in the Pensacola Bay Watershed Jane...

Atmospheric Deposition of Mercury, Trace Metals and Major

Ions in the Pensacola Bay Watershed

Jane CaffreyCenter for Environmental Diagnostics and Bioremedation

University of West Florida

and William M. LandingDepartment of Oceanography

Florida State University

Acknowledgements• EPA PERCH project• Melissa Overton, Autumn Dunn, Nathaniel Davila,

Tanner Martin, Fran Aftanas, Elizabeth Gaige , Brad Kuykendall for their dedication in the field

• Sara Cleveland, Kati Gosnell, and Nishanth Krishnamurthy at FSU

• Dr. Sikha Bagui and Jessie Brown at UWF Computer Science for database development

• Dr. Subhash Bagui and Arup Sinha at UWF Mathematics and Statistics

Escambia County 9th in total toxic emissions nationwide, 16th in air

emissions• Coal fired power plant• Papermill (coal for some

power generation) • Other industrial activities

(Solutia, Air Products, etc.)• 8 Superfund sites• Partnership for

Environmental Research and Community Health (PERCH) – EPA funded– Human health effects – Environmental effects

From Mark Cohen, NOAA ARL

Mercury emissions sources in the Gulf of Mexico region, based on the 1999 National Emissions Inventory (U.S. EPA)

Generally higher mercury deposition in the SE, most driven by higher rainfall

along the Gulf Coast

Mercury deposition is an international problem

Worldwide emission estimates

US coal fired power plants represent about 1% of Hg emissions globally53% of emissions come from Asia, 18% from Africa, 11% from Europe, 9% from North America

What is the atmospheric wet deposition of mercury, trace metals and major ions

to the lower Pensacola Bay Watershed?

• Are there seasonal patterns in deposition?

• How do prior weather conditions affect deposition?

• Are there hot spots?

• How important are Local sources?

Sampling Locations

Precipitation

Nov May Nov May Nov May Nov

cm

0

4

8

12

16

EllysonMolinoPace

Sample collection began in November 2004 and will continue

through March 2010

HurricaneDennis

~ 565 samples from 225 rain events to Feb 2008

2004 2005 2006 2007 2008

Analyses

UWF -WRL• pH• Sulfate• Nitrate+nitrite• Chloride• Ammonium• Sodium• Calcium• Phosphate

FSU - Oceanography• Mercury• Trace metals

– mineral/crustal elements: Al, Si, Sc, Ti, Mn, Fe, Rb, Y, Nb, Cs, La and all rare earth elements, Th, U

– Sea Salt aerosols: Li, Na, Mg, Sr

– urban pollution, fossil fuel combustion: V, Ga, Sb, Pb, Bi, P, Cu, Zn

– As, Se, Sn

Rain is generally acidic, sometimes highly acidic

VW

M p

H

3.6

4.0

4.4

4.8

5.2

5.6

6.0

Nov May Nov May Nov May Nov

pH

3

4

5

6

7

EllysonMolinoPace

2004 2005 2006 2007 2008

Sulfate Flux

Ellyson Molino Pace11/04 5/05 11/05 5/06 11/06 5/07 11/07

SO

42- fl

ux

mg

SO

42-/m

2/e

vent

0.1

1

10

100

1000 EllysonMolinoPace

Sulfate fluxes are higher in Pensacola and AL sites

0

500

1000

1500

2000

2500

3000

LA12 LA30 AL02 AL24 M E P FL14 FL23

SO

4 fl

ux

mg

SO

4/m

2/y

2005

2006

2007

Highest fluxes at EllysonLowest at FL14 and FL23

Counties with higher sulfate emissions have higher sulfate deposition

Sulfate

AL24 AL02

FL23

FL14

SREsc

r = 0.68

500

1000

1500

2000

100 1000 10000 100000

Emissions 2002 lbs/yr

Deposi

tion m

g/m

2/y

.

Based on EPA TRI estimates for 2002

Nitrate flux


NO

3- flux

mg

NO

3- /m2 /e

vent

0.1

1

10

100

1000EllysonMolino

Pace

Fluxes were similar at Pensacola Bay sitesHigher fluxes in spring and summer

Regional Nitrate Flux

0

500

1000

1500

2000

2500


NO

3 fl

ux

mg

NO

3/m

2/y

2005

2006

2007

Higher nitrate fluxes at Pensacola sites than at any NADP sites

Counties with higher nitrate emissions had higher nitrate deposition

Nitrate

AL24 AL02FL23

FL14

SREsc

r = 0.80

500

1000

1500

2000

0 10000 20000 30000 40000 50000 60000

Emissions 2002 lbs/yr

Deposi

tion m

g/m

2/y

.

Based on EPA TRI estimates for 2002

Chloride Flux


Cl- fl

ux

mg

Cl- /m

2 /eve

nt

0.1

1

10

100

1000

10000EllysonMolinoPace

Sodium and Chloride fluxes are high relative to other sitesP

0

500

1000

1500

2000

2500


Na

flu

x m

g/m

2/y

2005

2006

2007

Higher sodium and chloride fluxes when closer to Gulf of Mexico

R2 = 0.70

0

200

400

600

800

1000

1200

1400

0 20 40 60 80 100 120 140 160

Distance from Gulf, km

Ave

rage N

a+ fl

ux

mg/m

2/y

.

Conclusions

• Low pH in some rain events (pH usually < 5, sometimes less than 4)– Ellyson and Pace sites had significantly higher H+

fluxes than NADP sites

• Sulfate and nitrate fluxes higher at Pensacola Bay sites than most NADP sites

• Sulfate and Nitrate fluxes are highest in counties that have high SO2 or NOx emissions

• Sodium and Chloride fluxes higher at Pensacola Bay sites. Sea salt aerosols are important component of rain in the region

Mercury and trace elements in rainfall from the Pensacola airshed: local,

regional, and distant sources

William M. LandingDepartment of Oceanography

Florida State University Jane Caffrey

Center for Environmental Diagnostics and Bioremedation

University of West Florida

Acknowledgements• EPA PERCH project (2005-2008)• EPRI funding for 2008-present.• FSU Graduate students: Sara Cleveland, Kati Gosnell,

Nishanth Krishnamurthy• UWF students: Nathaniel Davila, Tanner Martin, Brad

Kuykendall, Fran Aftanas, Elizabeth Gaige

Geographic Distribution of Largest Anthropogenic Mercury Emissions Sources in the U.S. (1999) and

Canada (2000); from Mark Cohen NOAA/ARLGulf coast is not loaded with Hg point sources

Generally higher mercury deposition in the Southeastern US and along the Gulf coast.

Is this due to long-range transport of GEM and GEM-> RGM conversion during summer months? (Yes)

Escambia County:• Coal fired power plant• International Paper mill (coal

for some power generation) • Other industrial activities

(Solutia, Air Products, Sacred Heart medical waste incinerator, etc.)

EPA National Emissions Inventory shows that Plant Crist is the largest air emitter of mercury in the region.

-- Need reliable mercury speciation profile for each source

(RGM, GEM, Hg-p)

1999 2002 2005Mercury Mercury Mercury

Emissions Emissions Emissions(lb/yr) (lb/yr) (lb/yr) RGM GEM Hg-p

Plant Crist 220.0000 183.0000 191.0000 68% 25% 6%International Paper Company 46.5000 1.8600Sacred Heart Hospital 2.5600 0.0103 0.0020Perdido Landfill & Mrf 0.0395 0.0395 0.0395Naval Air Station Pensacola 0.0017 0.0000Baker & Son Construction Co. C&D Lf 0.0017 0.0017 0.0017Panhandle Paving & Grading (Long Lf) 0.0010 0.0010 0.0010Beulah Landfill 0.0010 0.0010 0.0010Camp Five Landfill 0.0008 0.0008 0.0008Auto Shred Industries Dump 0.0004 0.0004 0.0004Solutia Inc 0.1820

What is the atmospheric wet deposition of What is the atmospheric wet deposition of mercury, trace metals and major ions to the lower mercury, trace metals and major ions to the lower

Pensacola Bay Watershed? Pensacola Bay Watershed? Rainfall chemistry in the Pensacola region is impacted by multiple local and regional emission sources.

Rainfall mercury deposition in the southeastern US and along the Gulf of Mexico coast is already elevated due to long-range transport and transformation of Gaseous Elemental Mercury (GEM) to Reactive Gaseous Mercury (RGM); can we reliably quantify the impacts from individual local and regional sources of RGM (and particulate Hg-p)?

What is the seasonal pattern in mercury and trace element deposition? (Completed)

What are the relationships to local and regional meteorology? (On-going)

Are there hot spots? (Not apparent)

What is the atmospheric wet deposition of What is the atmospheric wet deposition of mercury, trace metals and major ions to the lower mercury, trace metals and major ions to the lower

Pensacola Bay Watershed? Pensacola Bay Watershed?

Can we use other trace elements to “fingerprint” specific emissions sources?

Installation of Hg emission control technology on the local CFPP (Plant Crist) in late 2009 may change local rainfall chemistry and trace element deposition.

Project is monitoring rain events at multiple sites for multiple years to obtain a statistically-significant number of such events both before and after new Hg emission control technology is installed.

Rainfall impact from a point-source plume requires simultaneous presence of the plume and rainfall.

Sampling Locations:1. Ellyson2. Pace3. Molino

a. b.

Modified AerochemMetrics Wet/Dry samplers:

1. Plexiglas splash guard on leading edge of roof to eliminate splash contamination.

2. Foam seal inside FEP Teflon film bag.

3. Three replicate “nested” funnel/bottle sets (one for pH, N-species and major ions; two for Hg and trace elements).

Analyses: Samples collected on an “event” basis (within 24 hours).

UWF -WRL• pH• Sulfate• Nitrate+nitrite• Chloride• Ammonium• Sodium• Calcium• Phosphate

FSU - Oceanography• Mercury• Trace metals

– mineral/crustal elements: Al, Si, Sc, Ti, Mn, Fe, Rb, Y, Nb, Cs, La and all rare earth elements, Th, U

– Sea Salt aerosols: Li, Na, Mg, Sr

– urban pollution, fossil fuel combustion: V, Ga, Sb, Pb, Bi, P, Cu, Zn, As, Se, Sn

0

10

20

30

40

50

60

0 10 20 30 40 50 60

Hg-A (ng/L)

Hg

-B (

ng

/L)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0

Se-A (ng/L)

Se

-B (

ng

/L)

0

2000

4000

6000

8000

10000

0 2000 4000 6000 8000 10000

Ba-A (ng/L)

Ba

-B (

ng

/L)

0.0

0.1

0.2

0.3

0.4

0.0 0.1 0.2 0.3 0.4

As-A (ng/L)

As-B

(n

g/L

)

Duplicate receiving bottles allows evaluation of analytical reliability. As concentrations approach the detection limit, scatter increases (Ba).

Sample collection:November 2004 through December 2007; ~ 500 samples

from 175 rain events at three sites.

Hg concentrations consistent with regional MDN sites.Generally higher in summer; small-volume winter events

have concentrations up to 55 ng/L.

Nov Mar Jul Nov Mar Jul Nov Mar Jul

Mer

cury

ng/

L

0

10

20

30

40

50

60

EllysonMolinoPace

2005 2006 2007

Monthly Mercury Deposition

0

100

200

300

400

500

N-04 M-05 O-05 M-06 O-06 A-07 O-07

Month beginning Nov 2004

ng

/cm

2/w

ee

k

EllysonMolinoPace

Mercury deposition per month: Mercury deposition per month: summertime deposition dominates due mostly to summertime deposition dominates due mostly to

higher rainfall Hg concentrations.higher rainfall Hg concentrations.

Pensacola sites are not significantly different from each other, and not significantly higher than

regional MDN sites

-

5,000

10,000

15,000

20,000

25,000

LA28 MS22 AL24 AL02 Molino Ellyson Pace

Rai

nfal

l Hg

Flu

x (n

g/m

^2)

2005

2006

2007

Plant CristUnits and In-Service Dates: 94 MW (1959), 94 MW (1961), 370 MW (1970), 578 MW (1973)

The increase in Hg sedimentation since 1965 (-45 years) also coincides with increased industrialization and coal-fired electricity generation throughout the southeast, nationally, and globally.

Need better local coring sites to define deposition history over the past 150 years.

Should we expect to be able to measure significant differences in Hg rainfall deposition due to Plant Crist?

1. “Background” rainfall Hg deposition is already elevated along the gulf coast (15-20 ug/m2/year).

2. RGM from CFPP may convert to GEM in near-field plume.

3. Individual CFPP impact from RGM emissions typically <15% of existing rainfall Hg deposition within 50 km in the southeastern US (Mark Cohen at NOAA/ARL).

So, rainfall Hg deposition may not be significantly elevated from Plant Crist. What other tools do we have?

Can we use multi-element analysis to “fingerprint” various sources of mercury and other trace elements in

Pensacola Bay rainfall?

Simple correlation and multi-variate statistical analysis used to examine relationships among mercury and trace

metals data (Factor Analysis and Positive Matrix Factorization).

Important to convert to “deposition” (Conc. x Rain depth) since small volume events have high concentrations of

all tracers and skew regression analysis.

Pensacola Rainfall (3 sites combined)

10

100

1000

10000

100000

10 100 1000 10000

Al Deposition (ug/m2)

Si d

epos

ition

(ug

/m2)


10

100

1000

10000

10 100 1000 10000

Al Deposition (ug/m2)

Fe

depo

sitio

n (u

g/m

2)

Crustal Factor: alumino-silicate aerosols (mineral dust)

Al, Si, Mn, Fe, Co, REE, Rb, Cs, Th, U


1

10

100

1000

10000

1 10 100 1000

Zn Deposition (ug/m2)

P d

epos

ition

(ug

/m2)


0.1

1

10

100

1000

1 100 10000 1000000

Mg Deposition (ug/m2)

Sr

depo

sitio

n (u

g/m

2)

Cd/Zn Factor: P, Cr, Zn, Cd Sea Salt Factor: Na, Mg, Sr


0.1

1

10

100

0.01 0.1 1 10

Hg Deposition (ug/m2)

As

de

po

sitio

n (

ug

/m2

)


0.1

1

10

0.01 0.1 1 10


Sn

de

po

sitio

n (

ug

/m2

)


0.01

0.1

1

10

100

0.01 0.1 1 10


Se

depo

sitio

n (u

g/m

2)

“Pollution” Factor: Hg vs. As, Sn, Se, Sb (volatiles in coal)Pensacola Rainfall (3 sites combined)

0.01

0.10

1.00

10.00

0.01 0.10 1.00 10.00


Sb

depo

sitio

n (u

g/m

2)R2 = 0.46

R2 = 0.54 R2 = 0.45

R2 = 0.27

Using volatile trace element concentrations to estimate Hg input from regional coal combustion (assumes volatile TE comes only from coal combustion):

1. Use Hg/TE vaporization ratios from CFPPs and “excess” rainfall TE and Hg deposition (adjust for RGM+Hg-p fraction (74%); assumes Hg/TE ratio is maintained until deposition):

%Hg from coal = Annual XS-TE deposition x (Hg/TE)coal x 100

Annual XS-Hg deposition

2. Or, use minimum observed XS-Hg/XS-TE ratios for volatile elements in rain samples to approximate Hg/TE from coal burning (average of 10-14 lowest ratios for each element).

%Hg in rainfall from regional coal combustion:

TE CFPP Hg/TE ratios Observed min. Hg/TE ratiosAs 29% 23%Se 38% 22%Sn 30% 14%Sb 40% 14%

Future Goals:

Use of meteorological data to understand the chemistry of individual rain events

Tags in Florida, updated simulation

35

44

Total Hg deposition (2001)= 25 ug/m2/yr

Wet Deposition (2005-2007)= 14-19 ug/m2/yr

Inferred Dry Deposition = 6-11 ug/m2/yr

78% of total Hg deposition from “background”

7.2% Plant Crist

8.2% from CFPP in Florida

45REMSAD results courtesy of Dwight Atkinson (EPA) and Tom Myers (ICF)

Conclusions and Future research• Rainfall mercury deposition in the Pensacola Bay watershed is similar to

deposition across the northeastern Gulf of Mexico.

• Factor Analysis and other statistical tests can be used to identify source “types”, but not individual point sources. Pensacola rainfall Hg deposition appears to be impacted by coal combustion sources (14-40%). Is this true along the entire Gulf coast? Need trace element analyses at MDN sites. New Gulf Breeze site will help.

• We will conduct detailed meteorological analysis of individual storms affecting all four monitoring sites within the region (includes EPRI/OLF site).– Back trajectories– Cloud-top heights (indicator of tall convection)– Prior meteorological history– Hg isotopes in large-volume samples (Summer 2010)

Atmospheric Deposition of Mercury, Trace Metals and Major Ions in the Pensacola Bay Watershed Jane...

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