tekran ® automated mercury speciation f.h. schaedlich 1, robert k. stevens 2, d.r. schneeberger 2,...
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TekranTekran®® Automated Mercury Automated Mercury SpeciationSpeciation
F.H. Schaedlich1 , Robert K. Stevens2,
D.R. Schneeberger2 , Eric Prestbo3,
Steve Lindberg4 , Gerald Keeler5
F.H. Schaedlich1 , Robert K. Stevens2,
D.R. Schneeberger2 , Eric Prestbo3,
Steve Lindberg4 , Gerald Keeler5 1 Tekran Inc., 1-132 Railside Rd. Toronto, Canada M3A 1A3, 1 Tekran Inc., 1-132 Railside Rd. Toronto, Canada M3A 1A3, 2 Florida Dept. Environmental Protection at USEPA, Res Triangle Park, NC 27711,2 Florida Dept. Environmental Protection at USEPA, Res Triangle Park, NC 27711,3 Frontier Geosciences Inc., 414 Pontius Ave. N., Suite B, Seattle, WA 981093 Frontier Geosciences Inc., 414 Pontius Ave. N., Suite B, Seattle, WA 981094 Oak Ridge National Lab. PO Box 2008, Oak Ridge, TN 37831-60384 Oak Ridge National Lab. PO Box 2008, Oak Ridge, TN 37831-60385 University of Michigan, School of Public Health, 109 Observatory Street, MI 48109.5 University of Michigan, School of Public Health, 109 Observatory Street, MI 48109.
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
ObjectivesObjectives
Development of Development of automated methodsautomated methods to to measure and differentiate between:measure and differentiate between: Reactive Gaseous Mercury (Reactive Gaseous Mercury (RGMRGM) in ambient ) in ambient
airair Total Particulate Mercury (Total Particulate Mercury (TPMTPM) in ambient air ) in ambient air Elemental mercury (Elemental mercury (HgHg00) in ambient air) in ambient air
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Ambient Air Mercury SpeciationAmbient Air Mercury Speciation
Different forms of gaseous Hg have very Different forms of gaseous Hg have very different behaviors.different behaviors.
Forms can interconvert in the atmosphere Forms can interconvert in the atmosphere and in various reservoirs.and in various reservoirs.
Classes of mercury in ambient air:Classes of mercury in ambient air: Elemental mercury: Elemental mercury: HgHg00.. Reactive mercury: Reactive mercury: HgHgIIII, , RGMRGM, , HgHg2+2+.. Particulate mercury: Particulate mercury: HgHgPP, , TPMTPM..
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Model 2537A Mercury AnalyzerModel 2537A Mercury AnalyzerProvides continuous total gaseous (Provides continuous total gaseous (TGMTGM) )
readings with update rate as low as readings with update rate as low as 2.52.5 minutes.minutes.
Detection limit Detection limit < 0.1 ng/m< 0.1 ng/m33 (5 min. samples).(5 min. samples).
Automatic recalibration with internal HgAutomatic recalibration with internal Hg00 permeation source.permeation source.
Capable of unattended operation for extended Capable of unattended operation for extended periods.periods.
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Model 2537A AnalyzerModel 2537A Analyzer
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Flow Diagram of Model 2537A Flow Diagram of Model 2537A Mercury AnalyzerMercury Analyzer
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Elemental Mercury: HgElemental Mercury: Hg00
Typically 90+% of atmospheric Hg Typically 90+% of atmospheric Hg loadings.loadings.
Relatively inert. Long residence time.Relatively inert. Long residence time.
HgHg00 sources impact large areas. sources impact large areas.
Sources: chlor-alkali plants, gold and Hg Sources: chlor-alkali plants, gold and Hg mining, thermal power plants.mining, thermal power plants.
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Why Bother Measuring RGM ?Why Bother Measuring RGM ?
RGMRGM (as (as HgClHgCl22) is emitted from power ) is emitted from power
plants and incinerators.plants and incinerators.
RGMRGM is removed rapidly via wet and dry is removed rapidly via wet and dry deposition.deposition.
Often responsible for contamination of Often responsible for contamination of sensitive nearby ecosystems. sensitive nearby ecosystems. (Florida (Florida Everglades, Arctic).Everglades, Arctic).
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Reactive Mercury: Hg(II) or RGMReactive Mercury: Hg(II) or RGMConsists of reactive, water soluble forms, Consists of reactive, water soluble forms,
primarily HgClprimarily HgCl22..
Usually only a few percent of total gaseous Usually only a few percent of total gaseous mercury present in the atmosphere.mercury present in the atmosphere.
Short range: deposits relatively close to the Short range: deposits relatively close to the source of emission.source of emission.
Primary sources: Coal burning power plants, Primary sources: Coal burning power plants, waste incinerators. waste incinerators. ((Chlor-alkali plantsChlor-alkali plants??))
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Difficulties Measuring RGMDifficulties Measuring RGMMethod must be 1-2 orders of magnitude Method must be 1-2 orders of magnitude
more sensitive than total mercury more sensitive than total mercury methods.methods.
Reject much larger Reject much larger elementalelemental component. component.
Exclude Exclude particulateparticulate bound mercury, bound mercury, however, particulate filters have problems however, particulate filters have problems passing passing RGMRGM..
Apparatus must pass Apparatus must pass RGMRGM to the collector to the collector quantitatively.quantitatively.
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Model 1130 - Principles of OperationModel 1130 - Principles of Operation
Quartz, specially coated annular denuder is Quartz, specially coated annular denuder is thermally desorbed and regenerated.thermally desorbed and regenerated.
Sampling Phase.Sampling Phase. Absorbs RGM while passing all elemental Hg.Absorbs RGM while passing all elemental Hg. Model 2537A reads Model 2537A reads HgHg00 during this phase. during this phase.
Desorption/Analysis Phase.Desorption/Analysis Phase. Zero air used as carrier.Zero air used as carrier. RGM released as RGM released as elementalelemental mercury. mercury.
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
RGM Sampling PhaseRGM Sampling PhaseDenuder is slightly warm.Denuder is slightly warm.
Inlet slightly warm.Inlet slightly warm.
Denuder captures all Denuder captures all RGM while passing HgRGM while passing Hg00..
Total sample flow is Total sample flow is 10 10 lpm.lpm.
Analyzer measures HgAnalyzer measures Hg00 during this time.during this time.
ZeroAir
SamplePump
MERCURY VAPOUR ANALYZER 2537A
AnnularDenuder
InletHeater
9 lpm 1 lpm
off
DenuderHeater
Ambient Air
OptionalModel 1135
Particulate Unit
Sampling Phase
Warm 50 ºC
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Analysis PhaseAnalysis PhaseDenuder is heated to Denuder is heated to
500500C.C. Inlet heated to clean Inlet heated to clean
upstream glassware.upstream glassware.Denuder releases captured Denuder releases captured
RGM as HgRGM as Hg00..Excess zero air flow cleans Excess zero air flow cleans
upstream components.upstream components. Instrument measures Instrument measures
accumulated RGM as Hgaccumulated RGM as Hg00..
ZeroAir
SamplePump
MERCURY VAPOUR ANALYZER 2537A
AnnularDenuder
InletHeater
off 1 lpm
6 lpm
DenuderHeater
ExcessZero Air
Heated 500 ºC
Desorption Phase
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Lab RGM ApparatusLab RGM Apparatus
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Quartz Denuder AssemblyQuartz Denuder Assembly
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Model 1130Model 1130Denuder & Denuder & Pump ModulePump Module
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Preliminary Results - TorontoPreliminary Results - Toronto RGM Comparison: SN:001, SN:002
May-23 12:00 May-24 00:00 May-24 12:00 May-25 00:00 May-25 12:00 May-26 00:00 May-26 12:00
1998
0
10
20
30
40
50
60
RG
M (
pg
/m3
)
RGM SN:001 (y)
RGM SN:002 (x)
SuccessiveDesorption (Blank Test)
Denuder Clean
Operation
Outdoor Air(Sampling through long inlet manifold)
Indoor Airy = 1.0595x - 0.5374
R2 = 0.9959
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Preliminary Results - TorontoPreliminary Results - TorontoElemental Mercury: SN:001 & SN:002
0
2
4
6
8
10
12
14
16
18
May-23 12:00 May-24 00:00 May-24 12:00 May-25 00:00 May-25 12:00 May-26 00:00 May-26 12:00
Date
Hg0 (
ng
/m3 )
Hg0 SN:001Hg0 SN:002
Outdoor Air
Indoor Air
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Lab Testing: Frontier GeosciencesLab Testing: Frontier Geosciences
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Seattle RGM DataSeattle RGM DataAmbient Air - Downtown SeattleAmbient Air - Downtown SeattleAmbient Air Hg(0) and RGM in Downtown Seattle
0
2
4
6
8
10
12
:30
00
:30
12
:30
00
:30
12
:30
00
:30
12
:30
00
:30
12
:30
00
:30
12
:30
00
:30
12
:30
00
:30
12
:30
00
:30
12
:30
00
:30
12
:30
August 22-31, 1998
Hg
(0)
(ng
/m3)
0
50
100
150
200
250
300
350
RG
M (
pg
/m3)
Hg(0) Tek-043 RGM Tek-043
Courtesy: Frontier GeosciencesCourtesy: Frontier Geosciences
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Mercury Levels - Rural MichiganMercury Levels - Rural Michigan
0
5
10
15
20
25
30
35
21:1
0
23:1
0
01:1
0
03:1
0
05:1
0
07:1
0
09:1
0
11:1
0
13:1
0
15:1
0
17:1
0
19:1
0
21:1
0
23:1
0
02:4
0
04:4
0
06:4
0
08:4
0
10:4
0
12:4
0
14:4
0
16:4
0
18:4
0
Time of Day (EDT)
RG
M (
pg
/m 3 )
.
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Hg
(0)
(ng
/m 3 )
.
Hg(II)Hg(0)
Dew Rain
27-Aug-98 29-Aug-9828-Aug-98
Courtesy: UMAQLCourtesy: UMAQL
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Summary - RGMSummary - RGM A quartz annular denuder coated with KCl A quartz annular denuder coated with KCl
quantitatively collects HgClquantitatively collects HgCl22 but does not retain but does not retain
HgHg0.0.
HgClHgCl22 collected on a denuder is thermally collected on a denuder is thermally
desorbed as Hgdesorbed as Hg0.0.
The automated instrument that uses this denuder The automated instrument that uses this denuder technology measures RGM concentrations down technology measures RGM concentrations down to 1 pg/mto 1 pg/m33..
Denuder lasts 1 - 2 weeks between recoatings.Denuder lasts 1 - 2 weeks between recoatings.
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Why Bother Measuring TPM ?Why Bother Measuring TPM ?
Particulate bound mercury (Particulate bound mercury (TPMTPM / / HgHgPP) is ) is created directly by some industrial created directly by some industrial processes and also formed downwind of processes and also formed downwind of sources by the combination of mercury sources by the combination of mercury with existing particulates.with existing particulates.
TPMTPM is removed rapidly via wet and dry is removed rapidly via wet and dry deposition.deposition.
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Particulate Mercury: TPMParticulate Mercury: TPMConsists of various compounds of mercury Consists of various compounds of mercury
bound onto particles.bound onto particles.Size range: Generally < 3 um.Size range: Generally < 3 um.Usually only a few percent of total mercury Usually only a few percent of total mercury
present in the atmosphere.present in the atmosphere.Short range: deposits relatively close to the Short range: deposits relatively close to the
source of emission.source of emission.
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Difficulties Measuring TPMDifficulties Measuring TPMMethod must be 1-2 orders of magnitude Method must be 1-2 orders of magnitude
more sensitive than total mercury more sensitive than total mercury methods.methods.
Must reject much larger Must reject much larger elementalelemental component.component.
Method must exclude Method must exclude reactive gaseous reactive gaseous mercury, however, normal particulate mercury, however, normal particulate filters have problems in that they retain filters have problems in that they retain RGMRGM..
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Model 1135 - Principles of OperationModel 1135 - Principles of Operation
Sampling PhaseSampling Phase Quartz, regenerable particulate filter (Quartz, regenerable particulate filter (RPFRPF) )
captures fine fraction (captures fine fraction (< 2.5 um< 2.5 um) particulates ) particulates after air has passed through impactor and after air has passed through impactor and denuderdenuder
Desorption/Analysis PhaseDesorption/Analysis Phase Zero air used as carrierZero air used as carrier Downstream Downstream pyrolyserpyrolyser is activated first is activated first RPF is heated to desorb captured particulatesRPF is heated to desorb captured particulates
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Model 1135 – Particulate Mercury MonitorModel 1135 – Particulate Mercury Monitor
Unit stacks on top of Model Unit stacks on top of Model 11301130
Allows simultaneous deter-Allows simultaneous deter-mination of Hgmination of Hg00, RGM and , RGM and HgPHgP
Detection limit ~ 1 pg/mDetection limit ~ 1 pg/m33
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Restrictor(100 ml/min)
MFM-1
CNCNO
ParticulateFilterPacks
Back PressureRegulator
BufferTank
ZeroScrubber
V2
500
75 35
Fan
CaseHeater
Zero Air (to Denuder Module)
Control & StatusSignals
ZeroScrubber(1st stage)
INLET
AirInlet
Vent
Heater &Temperature
SensorLeads
ZeroInlet
SampleInlet
PUMP MODULE
DENUDERMODULE
Model 2537AANALYZER
SamplePump
Control Cable
(Heated)
HEATED LINE
Interchangeable inlets: Impactor for ambient air or'Tee' piece for manifold
V1
50
MFM
CONTROLLER
ZeroOut
SampleIn
DenuderModuleControl
cable
NC C
NO
ZEROAIR
SAMPLE
600 40600
OvenCooling Fan
FritFilter
Wool
Dimples
QuartzChips
Pyrolyzer
ParticulateFilter
Teflon Union (90º)Tail
QuartzWool
OvenExhaust
CaseExhaust
Fan
SampleLine
CaseHeater
PARTICULATEMODULE
OvenExhaust
CaseExhaust
ControlConnector
ControlCable
GL14-GL18 Union
Thermal Safety Switch
Model 1135
Model 1130
Model 1130
Model 1130
Model 1130Model 1130& Model 1135 & Model 1135
Flow PathFlow Path
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Ambient Air SpeciationAmbient Air Speciation
Mercury Species: Hg°, TPM & RGM St.Anicet (Quebec)
0.0
1.0
2.0
Jan-26 Jan-27 Jan-28 Jan-29 Jan-30 Jan-31 Feb-01 Feb-02
Ele
me
nta
l Me
rcu
ry -
ng
/m³
.
0
100
200
300
400
RG
M &
TP
M -
pg
/m³
.
Elemental Mercury - Hg°
Total Particulate Mercury - TPM
Reactive Gaseous Mercury - RGM
Model 1130 & Model 1135Model 1130 & Model 1135
Model 1130 - Reactive Gaseous Mercury (RGM)
Model 1135 - Total Particulate Mercury (TPM)
Model 2537A - Elemental Mercury (Hg0)
Model 1130 - Reactive Gaseous Mercury (RGM)
Model 1135 - Total Particulate Mercury (TPM)
Model 2537A - Elemental Mercury (Hg0)
Tekran Automated Mercury SpeciationTekran Automated Mercury Speciation
Conclusions - HgPConclusions - HgP
A quartz RPF quantitatively collects particulate A quartz RPF quantitatively collects particulate mercury but does not retain Hgmercury but does not retain Hg00
HgP collected on a denuder is thermally HgP collected on a denuder is thermally desorbed and converted to Hgdesorbed and converted to Hg00 in the pyrolyzer in the pyrolyzer
Carbon based particulate matter on the filter is Carbon based particulate matter on the filter is oxidized to COoxidized to CO22 during desorption cycle during desorption cycle
Filter is usable for 1 – 2 weeks before requiring Filter is usable for 1 – 2 weeks before requiring restuffingrestuffing