Impacts of aerosols on the chemistry of atmospheric trace gases:
a case study of peroxides and HO2 radicals
H. Liang1, Z. M. Chen1, D. Huang1, Y. Zhao1 and Z. Y. Li1,2
1
State Key Laboratory of Environmental Simulation and Pollution Control, College of
Environmental Sciences and Engineering, Peking University, Beijing 100871, China
2
School of Earth and Space Sciences, Peking University, Beijing 100871, China
Correspondence to: Z. M. Chen ([email protected])
Supplementary material
Equation S1. Relationship between bulk and surface concentration of HO2
Table S1. Aerosol aqueous phase reactions extended in the box model calculation
Table S2. Sensitivity of HOx and H2O2 concentration to aerosol optical depth (AOD).
Fig.S1. Dependence of j-values on aerosol optical depth (AOD).
Equation S1. Relationship between bulk and surface concentration of HO2
The relationship between bulk and surface concentration of HO2 could be expresses
by the following equation (Mao et al., 2013):
(
)
(S1)
where kI is the first-order loss constant of HO2, PHO2 is the aqueous-phase production
rate of HO2, and q = a ( kI/Daq )1/2 is the diffuso-reactive parameter, in which a is the
radius of the particles, Daq is the HO2 aqueous phase diffusion constant. According to
this correction, the surface concentration is 100% to 180% of the bulk concentration,
depending on the radius of the particles and the concentrations of TMI.
Table S1. Aerosol aqueous phase reactions extended in the box model calculation.
NO. 1
Reactions
k298
Ea/R
R1
H2O2 + Fe2+ → Fe3+ + OH + OH−
7.0×101
5050
R2
H2O2 + FeO2+ → Fe3+ + HO2 + OH−
9.5×103
2800
R3
H2O2 + Fe(OH)+ → Fe(OH)2+ + OH + OH−
1.9×106
6200
R4
H2O2 + Fe3+ → Fe2+ + HO2 + H+
2.0×10−3
R5
H2O2 + Fe(OH)2+ → Fe2+ + HO2 + H2O
2.0×10−3
R6
O2− + Fe2+ + 2H+ → H2O2 + Fe3+
1.0×107
R7
O2− + Fe3+ → Fe2+ + O2
1.5×108
R8
O2− + Fe(OH)2+ → Fe2+ + O2 + OH−
1.5×108
R9
O2− + Fe(OH)2+ → Fe2+ + O2 + 2OH−
1.5×108
R10
HO2 + Fe2+ +H+ → Fe3+ + H2O2
1.2×106
R11
HO2 + FeO2+ → Fe3+ + O2 + OH−
2.0×106
R12
HO2 + Fe(OH)2+ → Fe2+ + O2 + H2O
1.3×105
R13
OH + Fe2+ → Fe(OH)2+
4.6×108
R14
OH + FeO2+ + H+ → Fe3+ + H2O2
1.0×107
R15
O3 + Fe2+ → FeO2+ + O2
8.2×105
R16
FeO2+ + H2O → Fe3+ + OH + OH−
1.3×10−2
4100
R17
FeO2+ + Fe2+ + H2O → 2Fe3+ + 2OH−
7.2×104
842
R18
Cl2− + Fe2+ → Fe3+ + 2Cl−
1.0×107
3060
R19
O2− + Fe(SO4)+ → Fe2+ + SO42− + O2
1.5×108
R20
HO2 + Fe(SO4)+ → Fe2+ + SO42− + O2 + H+
1.0×103
R21
Fe3+ + SO42− → Fe(SO4)+
3.2×103
R22
Fe(SO4)+ → Fe3+ + SO42−
2.7×101
R23
OH + Cu+→Cu2+ + OH−
3.0×109
R24
O2 + Cu+→Cu2+ + O2−
4.6×105
R25
H2O2 + Cu+→Cu2+ + OH + OH−
7.0×103
R26
HO2 + Cu+ + H+→Cu2+ + H2O2
3.5×109
R27
O2− + Cu+ + H+→Cu2+ + H2O2
9.4×109
R28
HO2 + Cu2+ → Cu+ + O2 + H+
1.0×108
R29
O2− + Cu2+ → Cu+ + O2
8.0×109
5050
1100
1
R30
HO2 + CuSO4 → Cu+ + O2 + HSO4−
1.0×107
R31
O2− + CuSO4 → Cu+ + O2 + SO42−
1.0×108
R32
Fe3+ + Cu+ → Cu2+ + Fe2+
1.3×107
R33
Fe(OH)2+ + Cu+ → Cu2+ + Fe2+ + OH−
3.0×107
R34
Fe(OH)2+ + Cu+ → Cu2+ + Fe2+ + 2OH−
1.3×107
R35
Fe(SO4)+ + Cu+ → Cu2+ + Fe2+ + SO42−
1.8×106
R36
OH + HO2 → H2O + O2
7.0×109
R37
OH + O2− → OH− + O2
1.0×1010
R38
OH + H2O2 → H2O + HO2
2.7×107
R39
HO2 + HO2 → H2O2 + O2
8.6×105
R40
HO2 + O2− → H2O2 + O2 + OH−
1.0×108
R41
O3 + O2− + H2O → OH + 2O2 + OH−
1.5×109
R42
SO2 + O3 + H2O → HSO4- + O2 + H+
2.4×104
R43
HSO3- + H2O2 + H+ → SO42- + H2O + 2H+
6.9×107
4000
R44
HSO3- + O3 → HSO4- + O2
3.7×105
5530
R45
SO32- + O3 → SO42- + O2
1.5×109
5280
P1
O3 + H2O → H2O2 + O2
2.98×10−4
P2
H2O2 → 2OH
4.81×10−6
P3
Fe3+ + H2O → Fe2+ + OH + H+
6.41×10−6
P4
Fe(OH)2+ → Fe2+ + OH
5.63×10−3
E1
Fe2+ + H2O ⇆ Fe(OH)+ + H+
3.22×10−10
E2
Fe3+ + H2O ⇆ Fe(OH)2+ + H+
6.0×10−3
E3
HO2 ⇆ O2− + H+
2.05×10−5
E4
H2O2 ⇆ HO2− + H+
1.6×10−12
E5
Cu2+ + SO42− ⇆ Cu(SO4)
2.3×102
E6
HSO4- ⇆ SO42- + H+
1.02×10−2
-2700
E7
HSO3- ⇆ SO32- + H+
6.22×10−8
-1960
R refers to reactions, P refers to photolysis, and E refers to equilibria.
-3700
Table S2. Sensitivity of HOx and H2O2 concentration to aerosol optical depth (AOD).
AOD
OH (pptv)
HO2 (pptv)
H2O2 (ppbv)
0
0.60
29.7
2.18
1
0.26
17.0
0.38
2
0.08
6.3
0.06
3
0.03
4.5
0.03
4
0.02
4.4
0.02
5
0.01
4.8
0.03
j(H2O2)
-5
3.0x10
j(HCHO)A
j(HCHO)B
-3
6.0x10
1
j(O D)
-3
4.0x10
-1
-1
j-value (s )
j(NO2)
j(NO2)(s )
-5
2.0x10
-5
1.0x10
-3
2.0x10
0.0
0.0
0
1
2
3
4
5
AOD
Fig. S1. Dependence of j-values on aerosol optical depth (AOD).
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