AEROSOL MODELING

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AEROSOL MODELING

• Kee-Youn Yoo
• University of Houston
• kyyoo_at_math.uh.edu

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Todays Lecture

• Atmospheric Inorganic Aerosol Description
• Box Model Simulation

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Typical Inorganic Aerosol Constitutes(Secondary)
Water
Sulfate
Nitrate
Sea Salt
Ammonium
Soil Dust
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Water - Hygroscopic Property
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Aerosol Water ?g/M-3
Solid
Liquid
RH
DRH Deliquescence Relative Humidity
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DRH
DRH
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DRH
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Sulfate
In the air
SO2 OH?
H2SO4 HO2?
Nucleation
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Continued
In the air
H2SO4

• Concentration difference between aerosol surface
  and air
• Particle size, etc.

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Nitrate, Ammonium

• Condensation and Evaporation
• HNO3, NH3

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Sea Salt
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H2O
Combustion Emissions Primary OC, EC
SO2 Emissions
Gas-Phase Photochemistry
HCl Emissions
S(IV)
H2SO4
HCl
Primary H2SO4
H, SO4- HSO4-
Cl-
Primary OC, EC
Na
NH3
Sea-Salt Emissions
NH3, OH-
Dust, Fly Ash Metals
NH3 Emissions
Condensible Organics
Secondary OC
NO3-, H
Ca2, Mg2 Fe3, etc.
HNO3
Gas-Phase Photochemistry
Gas-Phase Photochemistry
Gaseous Organics Emissions
Dust, Fly Ash Emissions
NOx Emissions
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Surface Chemical Reactions
Solid Particle
NH4HSO4
(NH4)2SO4

• Surface Chemical Reaction Rates
• Particle size, etc.

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Aerosol Simulation Structure
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Dynamic Module
Aerosol Dynamic Equation
Thermodynamics Ex. SCAPE2
Gas-Phase Reaction Ex. CB4 with sulfate chemistry
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Internal vs. External mixtures

• Internal Mixtures

• External Mixtures

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Thermodynamic Module
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• SCAPE2

Typical Urban Aerosol
NH3 - 3.4 ?g/m3, H2SO4 9.143 ?g/m3, HNO3
1.953 ?g/m3
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Typical Marine Aerosol
Na 1.967 ?g/m3, NH3 0.020 ?g/m3, H2SO4
0.510 ?g/m3, HNO3 0.163 ?g/m33 HCl 3.121
?g/m3
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Continued

• Key features
• Number of Chemical Species Treated
• Thermodynamic Models Activity Coefficients
• Solution Method to Thermodynamic Equilibriums

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BOX model simulation

• Sulfate Nucleation Only Gas Phase

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• Sulfate Nucleation Only Aerosol Phase (Smaller
  Section)

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• Sulfate Nucleation Only Aerosol Phase (Larger
  Section)

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T 5 hr
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T 15 hr
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• Sulfate Nucleation NH3 condensation Gas Phase

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• Sulfate Nucleation NH3 condensation Smaller
  Section

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• Sulfate Nucleation NH3 condensation Larger
  Section

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T 5 hr
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T 15 hr
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• Pre-existing Aerosol Effect Gas Phase

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• Pre-existing Aerosol Effect Smaller Section

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• Pre-existing Aerosol Effect Larger Section

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T 5 hr
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T 15 hr
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Tomorrows Lecture

• Aerosol Thermodynamic Formulation
• Introduction to the UHAERO Core Part

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Quiz

• What is this acid?

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Tableau Method

• Linear algebraic approach to solving chemical
  equilibrium problems
• Basis for computer codes that solve chemical
  equilibrium problems
• Another means of getting a TOTH equation
• Key think of reactions as mathematical
  equations H2O H OH- OH- H2O - H

François M.M. MorelIts a non-trivial problem.
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Tableau Method

• Pure water
• H2OT 55.5 M
• Reactions (Nrxn 1)
• H2O H OH-
• Species (Nspecies 3)
• H2O, H, and OH-
• Components
• Ncomp Nspecies Nrxn 2
• choose H2O and H

Its just a sign error.
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Tableau Method

• Cant have three components for pure water
• Choose too many componentsH2O, H, and OH-
• Cant have more than one way to make H2O with
  components H2O (H2O) and H2O
  (H) (OH-)

You must learn to think logarithmically.
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Tableau Method

• Add HAc to water
• H2OT 55.5 M
• HAcT 10-3 M
• Reactions (Nrxn 2)
• H2O H OH-
• HAc H Ac-
• Species (Nspecies 5)
• H2O, H, OH-, HAc, Ac-
• Components
• Ncomp Nspecies Nrxn 3
• choose H2O, H, HAc

I hope to have at least generally resisted a
natural propensity for reducing lively chemical
concepts to cold mathematics.
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Tableau Method

• Le tableau

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Tableau Method

• Mass Balances
• TOTH20 H2O OH- 55.5 M
• TOTHAc HAc Ac- 10-3 M
• TOTH H OH- Ac- 0
• Proton Condition

H OH- Ac- 0
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Tableau Method

• Use TOTH to solve for pH graphically
• TOTH H OH- Ac- 0

H ? Ac-
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Tableau Method

• Add NaAc to water
• H2OT 55.5 M
• NaAcT 10-3 M
• Reactions (Nrxn 2)
• H2O H OH-
• HAc H Ac-
• Species (Nspecies 6)
• H2O, H, OH-, HAc, Ac-, Na
• Components
• Ncomp Nspecies Nrxn 4
• choose H2O, H, Ac-, Na

I hope to have at least generally resisted a
natural propensity for reducing lively chemical
concepts to cold mathematics.
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Tableau Method

• Le tableau

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Tableau Method

• Mass Balances
• TOTH20 H2O OH- 55.5 M
• TOTAc HAc Ac- 10-3 M
• TOTNa Na 10-3 M
• TOTH H OH- HAc 0
• Proton Condition

H OH- HAc 0
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Tableau Method

• Use TOTH to solve for pH graphically
• TOTH H OH- HAc 0

HAc ? OH-
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Tableau Method

• Add sodium bicarbonate to water
• H2OT 55.5 M
• NaHCO3T 10-3 M
• Reactions (Nrxn 3)
• H2O H OH-
• H2CO3 H HCO3-
• HCO3- H CO32-
• Species (Nspecies 7)
• H2O, H, OH-, Na, H2CO3, HCO3-, CO32-
• Components
• Ncomp Nspecies Nrxn 4
• choose H2O, H, Na, HCO3-

For our purposes, the Boltzmann distribution may
be considered asGod-given.
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Tableau Method
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Tableau Method

• Mass Balances
• TOTH20 H2O OH- 55.5 M
• TOTHCO3 H2CO3 HCO3- CO32- 10-3 M
• TOTNa Na 10-3 M
• TOTH H OH- H2CO3 CO32- 0
• Proton Condition

H OH- H2CO3 CO32- 0
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Tableau Method

• Use TOTH to solve for pH graphically
• TOTH H OH- H2CO3 CO32- 0

H2CO3 ? CO32-
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More Religion (and Academic Ancestry)
James J. Morgan Marvin L. Goldberger Professor of
Environmental Engineering Science, California
Institute of Technology
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More Academic Ancestry
Werner Stumm Swiss Federal Institute for
Environmental Science and Technology
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Next Lecture

• Friday a lecture on the web, maybe
• Monday -- Alkalinity