Conceptual Models > Design of conceptual models
Question about parameter definitions in the dissolution reaction of NO2 and SO2
(1/1)
Amuer:
Hello
I'm now working with a simulation to find the effect of SO2 and NO2 as gas impurities on subsurface CO2 storage.
I've finished my simulation and now plan to do experiment at Laboratory.
I'm going to add the components which are considered to be formed by the dissolution of SO2 and NO2 based on the results of the simulation, instead of bubbling SO2 and NO2 gases exactly.
So I want to know what will be formed due to the bubbling of SO2 and NO2, and I carried out this simulation.
--- Code: ---SOLUTION_SPECIES
1.0000 SO4-- = SO3-- +0.5000 O2
-gamma 4.5
log_k -46.6244
1.0000 SO3-- + 1.0000 H+ = HSO3-
-gamma 4.0
log_k +7.2054
2.0000 H+ + 2.0000 SO3-- = S2O4-- + .500 O2 + H2O
-gamma 5.0
log_k -25.2076
2 H+ + SO3-2 = SO2 + H2O
-gamma 3.0
log_k 9.0656
-delta_H 26.7316 kJ/mol
# deltafH -77.194 kcal/mol
-analytic 9.4048e1 6.2127e-2 -1.1072e3 -4.0310e1 -1.7305e1
# Range 0-350
-Vm 6.9502 9.189 2.1383 -3.1589 -0.0559
# Extrapol supcrt92
# Ref SHS89
KNOBS
-iterations 2000
-tolerance 1E-15
-step_size 3
-pe_step_size 3
-diagonal_scale true
PHASES
Calcite
CaCO3 + H+ = Ca+2 + HCO3-
log_k 1.8487
-delta_H -25.7149 kJ/mol
Dolomite
CaMg(CO3)2 + 2 H+ = Ca+2 + Mg+2 + 2 HCO3-
log_k 2.5135
-delta_H -59.9651 kJ/mol
Quartz
SiO2 + 2 H2O = H4SiO4
-log_k -3.98
-delta_h 5.990 kcal
Siderite
FeCO3 + H+ = Fe+2 + HCO3-
log_k -0.1920
-delta_H -32.5306 kJ/mol
Pyrite
FeS2 + 2 H+ + 2 e- = Fe+2 + 2 HS-
-log_k -18.479
-delta_h 11.300 kcal
SO2(g)
SO2 = SO2
log_k 0.1700
-delta_H 0
-analytic -2.0205e1 2.8861e-3 1.4862e3 5.2958 1.2721e5
-T_c 430 # K
-P_c 77.67
-Omega 0.251 # http://webserver.dmt.upm.es/~isidoro/dat1/eGAS.pdf
NO2(g)
NO2 + 0.5 H2O + 0.25 O2 = H+ + NO3-
log_k 8.3673
-delta_H -94.0124 kJ/mol
-analytic 9.4389e1 -2.7511e-1 -1.6783e4 2.1127e1 -2.6191e2
-T_c 431 # K
-P_c 99.67
-Omega 0 # Not found
H2S(g)
H2S = H+ + HS-
log_k -7.9759
-delta_H 4.5229 kJ/mol
-analytic -97.354 -3.1576e-2 1.8285e3 37.44 28.56
-T_c 373.2 # K
-P_c 88.20
-Omega 0.1
SOLUTION 1
ph 7 charge
-units ppm
-pressure 1
-temperature 25
Na 23867
Ca 13961
Mg 2177
Cl 57606
S(6) 5571 as SO4
K 0
C 243 as HCO3
-water 0.1
GAS_PHASE 1
-pressure 1
-fixed_pressure
-volume 100 #Gas total volume
-temp 25
CO2(g) 80 #Litres
SO2(g) 10
NO2(g) 10
--- End code ---
and get a result like this
--- Code: --------------------------------------Gas phase-----------------------------------
Total pressure: 1.00 atmospheres (Peng-Robinson calculation)
Gas volume: 5.08e+04 liters
Molar volume: 2.43e+01 liters/mole
P * Vm / RT: 0.99337 (Compressibility Factor Z)
Moles in gas
----------------------------------
Component log P P phi Initial Final Delta
CO2(g) -0.10 8.008e-01 0.995 1.675e+03 1.675e+03 4.432e-04
NO2(g) -1.00 9.978e-02 0.991 2.094e+02 2.087e+02 -6.686e-01
SO2(g) -1.00 9.946e-02 0.987 2.094e+02 2.080e+02 -1.337e+00
-----------------------------Solution composition------------------------------
Elements Molality Moles
C 1.301e-05 9.917e-07
Ca 5.095e-01 3.885e-02
Cl 2.377e+00 1.812e-01
Mg 1.310e-01 9.987e-03
N 8.768e+00 6.686e-01
Na 1.519e+00 1.158e-01
S 1.762e+01 1.344e+00
----------------------------Description of solution----------------------------
pH = -1.374 Charge balance
pe = 41.069 Adjusted to redox equilibrium
Specific Conductance (ｵS/cm, 25ｰC) = 820357
Density (g/cmｳ) = 0.71571
Volume (L) = 0.31891
Viscosity (mPa s) = 0.89002
Activity of water = 0.000
Ionic strength (mol/kgw) = 5.029e+01
Mass of water (kg) = 7.625e-02
Total alkalinity (eq/kg) = -3.482e+01
Total CO2 (mol/kg) = 1.301e-05
Temperature (ｰC) = 25.00
Electrical balance (eq) = 2.294e-11
Percent error, 100*(Cat-|An|)/(Cat+|An|) = 0.00
Iterations = 132 (2133 overall)
Total H = 1.111966e+01
Total O = 9.606654e+00
----------------------------Distribution of species----------------------------
Log Log Log mole V
Species Molality Activity Molality Activity Gamma cmｳ/mol
H+ 3.457e+01 2.366e+01 1.539 1.374 -0.165 0.00
H2O 5.551e+01 7.502e-37 1.744 -36.125 0.000 18.07
OH- 0.000e+00 0.000e+00 -51.099 -51.494 -0.395 57.36
C(-4) 0.000e+00
CH4 0.000e+00 0.000e+00 -227.512 -222.484 5.029 35.46
C(4) 1.301e-05
CO2 1.301e-05 2.710e-02 -4.886 -1.567 3.319 34.43
(CO2)2 1.262e-10 1.348e-05 -9.899 -4.870 5.029 68.87
CaHCO3+ 0.000e+00 0.000e+00 -40.423 -40.665 -0.241 123.10
MgHCO3+ 0.000e+00 0.000e+00 -42.351 -42.701 -0.351 6.10
HCO3- 0.000e+00 0.000e+00 -45.151 -45.418 -0.266 124.67
CaCO3 0.000e+00 0.000e+00 -54.757 -49.729 5.029 -14.60
NaHCO3 0.000e+00 0.000e+00 -54.857 -44.800 10.057 31.73
CO3-2 0.000e+00 0.000e+00 -56.055 -57.121 -1.065 47.36
MgCO3 0.000e+00 0.000e+00 -57.521 -52.493 5.029 -17.09
Ca 5.095e-01
CaSO4 2.620e-01 1.000e+03 -0.582 4.447 5.029 7.50
CaHSO4+ 2.464e-01 1.000e+03 -0.608 6.639 7.247 (0)
Ca+2 1.031e-03 1.000e+03 -2.987 4.167 7.153 1.80
CaHCO3+ 0.000e+00 0.000e+00 -40.423 -40.665 -0.241 123.10
CaOH+ 0.000e+00 0.000e+00 -53.359 -46.112 7.247 (0)
CaCO3 0.000e+00 0.000e+00 -54.757 -49.729 5.029 -14.60
Cl 2.377e+00
Cl- 2.377e+00 7.053e+00 0.376 0.848 0.472 22.54
HCl 2.282e-20 5.749e+01 -19.642 1.760 21.401 (0)
H(0) 0.000e+00
H2 0.000e+00 0.000e+00 -87.568 -82.539 5.029 28.61
Mg 1.310e-01
Mg(SO4)2-2 1.310e-01 4.412e+00 -0.883 0.645 1.527 84.74
Mg+2 4.352e-08 4.450e+01 -7.361 1.648 9.010 0.61
MgSO4 1.096e-08 1.249e+02 -7.960 2.097 10.057 -7.92
MgHCO3+ 0.000e+00 0.000e+00 -42.351 -42.701 -0.351 6.10
MgOH+ 0.000e+00 0.000e+00 -47.067 -47.291 -0.224 (0)
MgCO3 0.000e+00 0.000e+00 -57.521 -52.493 5.029 -17.09
N(0) 8.768e+00
N2 4.384e+00 1.000e+03 0.642 5.670 5.029 29.29
N(3) 5.997e-27
NO2- 5.997e-27 2.114e-27 -26.222 -26.675 -0.453 31.63
N(5) 2.967e-12
NO3- 2.967e-12 1.046e-12 -11.528 -11.980 -0.453 40.59
Na 1.519e+00
NaSO4- 1.518e+00 8.305e-01 0.181 -0.081 -0.262 72.40
Na+ 7.913e-04 4.758e+00 -3.102 0.677 3.779 6.54
NaHCO3 0.000e+00 0.000e+00 -54.857 -44.800 10.057 31.73
NaOH 0.000e+00 0.000e+00 -65.845 -60.816 5.029 (0)
O(0) 5.125e-05
O2 2.631e-05 2.810e+00 -4.580 0.449 5.029 30.40
SO2 1.377e-06 1.471e-01 -5.861 -0.833 5.029 38.03
HSO3- 1.293e-40 0.000e+00 -39.888 -40.239 -0.351 (0)
SO3-2 0.000e+00 0.000e+00 -47.559 -48.818 -1.260 (0)
S2O4-2 0.000e+00 0.000e+00 -83.052 -84.196 -1.144 (0)
S(-2) 0.000e+00
H2S 0.000e+00 0.000e+00 -136.716 -131.687 5.029 36.27
HS- 0.000e+00 0.000e+00 -139.608 -140.003 -0.395 27.26
S-2 0.000e+00 0.000e+00 -153.151 -154.295 -1.144 (0)
(H2S)2 0.000e+00 0.000e+00 -269.681 -264.653 5.029 30.09
S(6) 1.762e+01
SO4-2 1.533e+01 1.072e-02 1.186 -1.970 -3.155 187.48
NaSO4- 1.518e+00 8.305e-01 0.181 -0.081 -0.262 72.40
CaSO4 2.620e-01 1.000e+03 -0.582 4.447 5.029 7.50
CaHSO4+ 2.464e-01 1.000e+03 -0.608 6.639 7.247 (0)
Mg(SO4)2-2 1.310e-01 4.412e+00 -0.883 0.645 1.527 84.74
HSO4- 1.397e-06 2.467e+01 -5.855 1.392 7.247 42.61
SO2 1.377e-06 1.471e-01 -5.861 -0.833 5.029 38.03
MgSO4 1.096e-08 1.249e+02 -7.960 2.097 10.057 -7.92
HSO3- 1.293e-40 0.000e+00 -39.888 -40.239 -0.351 (0)
SO3-2 0.000e+00 0.000e+00 -47.559 -48.818 -1.260 (0)
S2O4-2 0.000e+00 0.000e+00 -83.052 -84.196 -1.144 (0)
------------------------------Saturation indices-------------------------------
Phase SI** log IAP log K(298 K, 1 atm)
Anhydrite 6.47 2.20 -4.28 CaSO4
Aragonite -44.62 -52.95 -8.34 CaCO3
Calcite -44.47 -42.63 1.85 CaCO3
CH4(g) -219.68 -222.48 -2.80 CH4
CO2(g) -0.10 -1.57 -1.47 CO2 Pressure 0.8 atm, phi 0.995
Dolomite -90.28 -87.77 2.51 CaMg(CO3)2
Epsomite -251.46 -253.20 -1.74 MgSO4:7H2O
Gypsum -65.47 -70.05 -4.58 CaSO4:2H2O
H2(g) -79.44 -82.54 -3.10 H2
H2O(g) -37.63 -36.12 1.50 H2O
H2S(g) -130.64 -138.63 -7.99 H2S
Halite -0.04 1.53 1.57 NaCl
Hexahydrite -215.50 -217.07 -1.57 MgSO4:6H2O
Kieserite -35.28 -36.45 -1.16 MgSO4:H2O
Mirabilite -360.62 -361.86 -1.24 Na2SO4:10H2O
N2(g) 8.85 5.67 -3.18 N2
NO2(g) -1.01 7.34 8.35 NO2 Pressure 0.1 atm, phi 0.991
O2(g) 3.34 0.45 -2.89 O2
SO2(g) -1.01 -0.83 0.18 SO2 Pressure 0.1 atm, phi 0.987
Sulfur -57.18 -52.30 4.88 S
Thenardite -0.31 -0.61 -0.30 Na2SO4
**For a gas, SI = log10(fugacity). Fugacity = pressure * phi / 1 atm.
For ideal gases, phi = 1.
--- End code ---
I'm now somehow confused with how to tell what is formed directly due to the injection of SO2 and NO2.
Can anybody tell me if the paramater definitions are correct and how can I get the components formed by SO2 and NO2?
Amuer:
I also tried to reduce the total volume of gas phase to 0.05L to make the gas-liquid ratio meet the definition in my simulation.
But i got some error
--- Code: ---Reaction step 1.
WARNING: Maximum iterations exceeded, 2000
WARNING: Numerical method failed with this set of convergence parameters.
WARNING: Trying reduced tolerance 1e-16 ...
WARNING: Maximum iterations exceeded, 4000
WARNING: Numerical method failed with this set of convergence parameters.
WARNING: Trying increased tolerance 1e-14 ...
WARNING: Maximum iterations exceeded, 4000
WARNING: Numerical method failed with this set of convergence parameters.
WARNING: Trying diagonal scaling ...
WARNING: Maximum iterations exceeded, 4000
WARNING: Numerical method failed with this set of convergence parameters.
WARNING: Trying diagonal scaling and reduced tolerance 1e-16 ...
WARNING: Maximum iterations exceeded, 4000
WARNING: Numerical method failed with this set of convergence parameters.
WARNING: Trying scaling pure_phase columns 1e-10 ...
WARNING: Maximum iterations exceeded, 4000
WARNING: Numerical method failed with this set of convergence parameters.
WARNING: Trying scaling pure_phase columns and diagonal scale 1e-10 ...
WARNING: Maximum iterations exceeded, 4000
WARNING: Numerical method failed with this set of convergence parameters.
WARNING: Trying increased scaling 1e-09 ...
WARNING: Maximum iterations exceeded, 4000
WARNING: Numerical method failed with this set of convergence parameters.
WARNING: Skipping optimize equations for first 5 iterations ...
WARNING: Maximum iterations exceeded, 2000
WARNING: Numerical method failed with this set of convergence parameters.
WARNING: Adding inequality to make concentrations greater than zero.
WARNING: Maximum iterations exceeded, 2000
WARNING: Numerical method failed with this set of convergence parameters.
WARNING: Trying reduced tolerance 1e-17 ...
WARNING: Maximum iterations exceeded, 4000
WARNING: Numerical method failed with this set of convergence parameters.
WARNING: Trying reduced tolerance 1e-18 ...
WARNING: Maximum iterations exceeded, 4000
WARNING: Numerical method failed with this set of convergence parameters.
WARNING: The program has failed to converge to a numerical solution.
The following equations were not satisfied:
ERROR: gas moles Total moles in gas phase has not converged. Residual: 1.000000e+00
Using solution 1.
Using gas phase 1.
-----------------------------------Gas phase-----------------------------------
Total pressure: 1.00 atmospheres (Peng-Robinson calculation)
Gas volume: 2.49e-03 liters
Molar volume: 2.43e+01 liters/mole
P * Vm / RT: 0.99445 (Compressibility Factor Z)
Moles in gas
----------------------------------
Component log P P phi Initial Final Delta
CO2(g) -11.09 8.162e-12 0.994 8.177e-05 8.343e-16 -8.177e-05
NO2(g) -21.69 2.057e-22 0.991 1.022e-05 0.000e+00 -1.022e-05
SO2(g) -57.82 1.518e-58 0.988 1.022e-05 0.000e+00 -1.022e-05
-----------------------------Solution composition------------------------------
Elements Molality Moles
C 5.259e-03 5.259e-04
Ca 3.885e-01 3.885e-02
Cl 1.812e+00 1.812e-01
Mg 9.987e-02 9.987e-03
N 1.022e-04 1.022e-05
Na 1.158e+00 1.158e-01
S 6.478e-02 6.478e-03
----------------------------Description of solution----------------------------
pH = 12.472 Charge balance
pe = 5.247 Adjusted to redox equilibrium
Specific Conductance (ｵS/cm, 25ｰC) = 137502
Density (g/cmｳ) = 1.08127
Volume (L) = 0.10345
Viscosity (mPa s) = 1.11654
Activity of water = 0.940
Ionic strength (mol/kgw) = 2.282e+00
Mass of water (kg) = 1.000e-01
Total alkalinity (eq/kg) = 1.928e-01
Total CO2 (mol/kg) = 5.259e-03
Temperature (ｰC) = 25.00
Electrical balance (eq) = 3.008e-13
Percent error, 100*(Cat-|An|)/(Cat+|An|) = 0.00
Iterations = 4001 (42012 overall)
Total H = 1.111966e+01
Total O = 5.596446e+00
----------------------------Distribution of species----------------------------
Log Log Log mole V
Species Molality Activity Molality Activity Gamma cmｳ/mol
OH- 5.394e-02 2.821e-02 -1.268 -1.550 -0.282 -0.22
H+ 4.666e-13 3.373e-13 -12.331 -12.472 -0.141 0.00
H2O 5.551e+01 9.401e-01 1.744 -0.027 0.000 18.07
C(-4) 0.000e+00
CH4 0.000e+00 0.000e+00 -130.092 -129.864 0.228 35.46
C(4) 5.259e-03
CaCO3 4.781e-03 8.087e-03 -2.320 -2.092 0.228 -14.60
CO3-2 3.275e-04 4.760e-05 -3.485 -4.322 -0.838 3.03
MgCO3 1.498e-04 2.534e-04 -3.824 -3.596 0.228 -17.09
HCO3- 5.545e-07 3.424e-07 -6.256 -6.465 -0.209 28.69
CaHCO3+ 2.086e-07 1.336e-07 -6.681 -6.874 -0.194 123.00
NaHCO3 1.001e-07 2.865e-07 -6.999 -6.543 0.456 31.73
MgHCO3+ 4.049e-08 2.235e-08 -7.393 -7.651 -0.258 5.93
CO2 1.953e-13 2.762e-13 -12.709 -12.559 0.151 34.43
(CO2)2 8.280e-28 1.400e-27 -27.082 -26.854 0.228 68.87
Ca 3.885e-01
Ca+2 3.263e-01 1.011e-01 -0.486 -0.995 -0.509 -15.80
CaOH+ 4.243e-02 4.677e-02 -1.372 -1.330 0.042 (0)
CaSO4 1.503e-02 2.542e-02 -1.823 -1.595 0.228 7.50
CaCO3 4.781e-03 8.087e-03 -2.320 -2.092 0.228 -14.60
CaHCO3+ 2.086e-07 1.336e-07 -6.681 -6.874 -0.194 123.00
CaHSO4+ 5.112e-14 5.636e-14 -13.291 -13.249 0.042 (0)
Cl 1.812e+00
Cl- 1.812e+00 1.052e+00 0.258 0.022 -0.236 19.37
HCl 1.305e-14 1.222e-13 -13.884 -12.913 0.971 (0)
H(0) 3.059e-39
H2 1.529e-39 2.587e-39 -38.815 -38.587 0.228 28.61
Mg 9.987e-02
MgOH+ 8.589e-02 5.644e-02 -1.066 -1.248 -0.182 (0)
Mg+2 1.307e-02 5.578e-03 -1.884 -2.254 -0.370 -19.47
MgSO4 7.216e-04 2.064e-03 -3.142 -2.685 0.456 -7.92
MgCO3 1.498e-04 2.534e-04 -3.824 -3.596 0.228 -17.09
Mg(SO4)2-2 3.668e-05 9.611e-06 -4.436 -5.017 -0.582 43.05
MgHCO3+ 4.049e-08 2.235e-08 -7.393 -7.651 -0.258 5.93
N(0) 6.133e-05
N2 3.066e-05 5.187e-05 -4.513 -4.285 0.228 29.29
N(3) 5.904e-12
NO2- 5.904e-12 2.895e-12 -11.229 -11.538 -0.310 26.36
N(5) 4.089e-05
NO3- 4.089e-05 2.004e-05 -4.388 -4.698 -0.310 31.09
Na 1.158e+00
Na+ 1.122e+00 9.606e-01 0.050 -0.017 -0.068 0.24
NaSO4- 3.557e-02 2.210e-02 -1.449 -1.656 -0.207 20.49
NaHCO3 1.001e-07 2.865e-07 -6.999 -6.543 0.456 31.73
NaOH 1.602e-12 2.710e-12 -11.795 -11.567 0.228 (0)
O(0) 6.510e-16
O2 3.255e-16 5.505e-16 -15.487 -15.259 0.228 30.40
SO3-2 0.000e+00 0.000e+00 -40.891 -41.845 -0.953 (0)
HSO3- 0.000e+00 0.000e+00 -46.853 -47.111 -0.258 (0)
SO2 0.000e+00 0.000e+00 -57.877 -57.649 0.228 38.03
S2O4-2 0.000e+00 0.000e+00 -125.299 -126.184 -0.885 (0)
S(-2) 0.000e+00
S-2 0.000e+00 0.000e+00 -122.874 -123.759 -0.885 (0)
HS- 0.000e+00 0.000e+00 -123.032 -123.313 -0.282 22.00
H2S 0.000e+00 0.000e+00 -129.072 -128.844 0.228 36.27
(H2S)2 0.000e+00 0.000e+00 -259.194 -258.965 0.228 30.09
S(6) 6.478e-02
NaSO4- 3.557e-02 2.210e-02 -1.449 -1.656 -0.207 20.49
CaSO4 1.503e-02 2.542e-02 -1.823 -1.595 0.228 7.50
SO4-2 1.339e-02 1.413e-03 -1.873 -2.850 -0.977 56.45
MgSO4 7.216e-04 2.064e-03 -3.142 -2.685 0.456 -7.92
Mg(SO4)2-2 3.668e-05 9.611e-06 -4.436 -5.017 -0.582 43.05
CaHSO4+ 5.112e-14 5.636e-14 -13.291 -13.249 0.042 (0)
HSO4- 4.205e-14 4.635e-14 -13.376 -13.334 0.042 41.48
SO3-2 0.000e+00 0.000e+00 -40.891 -41.845 -0.953 (0)
HSO3- 0.000e+00 0.000e+00 -46.853 -47.111 -0.258 (0)
SO2 0.000e+00 0.000e+00 -57.877 -57.649 0.228 38.03
S2O4-2 0.000e+00 0.000e+00 -125.299 -126.184 -0.885 (0)
------------------------------Saturation indices-------------------------------
Phase SI** log IAP log K(298 K, 1 atm)
Anhydrite 0.43 -3.84 -4.28 CaSO4
Aragonite 3.02 -5.32 -8.34 CaCO3
Calcite 3.16 5.01 1.85 CaCO3
CH4(g) -127.06 -129.86 -2.80 CH4
CO2(g) -11.09 -12.56 -1.47 CO2 Pressure 1.0 atm, phi 0.994
Dolomite 6.25 8.76 2.51 CaMg(CO3)2
Epsomite -3.55 -5.29 -1.74 MgSO4:7H2O
Gypsum 0.68 -3.90 -4.58 CaSO4:2H2O
H2(g) -35.49 -38.59 -3.10 H2
H2O(g) -1.53 -0.03 1.50 H2O
H2S(g) -127.79 -135.79 -7.99 H2S
Halite -1.57 0.00 1.57 NaCl
Hexahydrite -3.70 -5.26 -1.57 MgSO4:6H2O
Kieserite -3.97 -5.13 -1.16 MgSO4:H2O
Mirabilite -1.91 -3.15 -1.24 Na2SO4:10H2O
N2(g) -1.11 -4.29 -3.18 N2
NO2(g) -21.69 -13.34 8.35 NO2 Pressure 0.0 atm, phi 0.991
O2(g) -12.37 -15.26 -2.89 O2
SO2(g) -57.82 -57.65 0.18 SO2 Pressure 0.0 atm, phi 0.988
Sulfur -98.29 -93.41 4.88 S
Thenardite -2.58 -2.88 -0.30 Na2SO4
**For a gas, SI = log10(fugacity). Fugacity = pressure * phi / 1 atm.
For ideal gases, phi = 1.
ERROR: Numerical method failed on all combinations of convergence parameters, cell/soln/mix 1
Stopping.
--- End code ---
Does this mean the volume of gas phase is too small compared to the solution?
How can I change the paramater?
dlparkhurst:
SO2 is not stable thermodynamically, so it reacts to form S(-2) and S(6). See this post for details https://phreeqcusers.org/index.php/topic,2515.msg9438.html#msg9438
If you want to model SO2 solubility, you will need to define it separately from the rest of the sulfur (S) system, same with NO2.
See this post to define a new element and species for SO2 https://phreeqcusers.org/index.php/topic,2290.msg8501.html#msg8501
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