Introduction to PHREEQC—Chemistry for PHAST

PHAST Flow Transport HST3D—Flow and transport PHREEQC—Chemistry Operator splitting—Sequential Non-Iterative Approach Chemistry Transport Flow

PHREEQC PHAST chemistry is inherited from PHREEQC PHREEQC is run at the beginning of PHAST Solutions and reactants for initial conditions Solutions for boundary conditions PHREEQC is run cell-by-cell for each time step in the reactive-transport simulation

PHREEQC Reactants Keyword data blocks define reactants SOLUTION—Solutions EQUILIBRIUM_PHASES—Equilibrium minerals and gases EXCHANGE—Exchangers SURFACE—Surfaces KINETICS and RATES—Kinetic reactions SOLID_SOLUTIONS—Solid solutions GAS_PHASE—gas bubble (rarely used) Store reactants on shelves by type and number

SOLUTION—Chemical Composition of a Water Chemical analysis pH Temperature Major elements Ca, Mg, Na, K, Alkalinity, Cl, SO4 Trace elements Nutrients

SOLUTION Data Block SOLUTION 1: Oklahoma Brine units mol/kgw pH 5.713 temp 25. Ca .4655 Mg .1609 Na 5.402 Cl 6.642 C .00396 S .004725 As .03 (ug/kgw)

EQUILIBRIUM_PHASES Minerals and gases that react to equilibrium Calcite reaction CaCO3 = Ca+2 + CO3-2 Equilibrium K = [Ca+2][CO3-2]

EQUILIBRIUM_PHASES Data Block Mineral or gas Saturation state Amount Example EQUILIBRIUM_PHASES 5: CO2 Log PCO2 = -2, 10 moles Calcite equilibrium 1 moles Dolomite equilibrium 1 moles Fe(OH)3 equilibrium 0 moles

EXCHANGE Cation exchange composition Reaction: Ca+2 + 2NaX = CaX2 + 2Na+ Equilibrium:

EXCHANGE Data Block Exchanger name Number of exchange sites Chemical composition of exchanger Example EXCHANGE 15: CaX2 0.05 moles (X is defined in databases) NaX 0.05 moles Often X 0.15 moles, Equilibrium with solution 1

SURFACE—Surface Composition Trace elements Zn, Cd, Pb, As, P Reaction: Hfo_wOH + AsO4-3 = Hfo_wOHAsO4-3 Equilibrium:

SURFACE Data Block Example SURFACE 21: Surface name—Hfo is Hydrous Ferric Oxide Number of surface sites Chemical composition of surface Example SURFACE 21: Hfo_wOH 0.001 moles Hfo_sOH 0.00005 moles Often Hfo_w 0.001 moles, Equilibrium with solution 1

KINETICS—Nonequilibrium Reactions Monod Kinetics Radioactive decay Silicate hydrolosis Biological processes

KINETICS and RATES Data Blocks Kinetic reaction name Stoichiometry of reaction Rate expression (RATES) Example KINETICS 21: DOC_decay formula Doc -1 CH2O +1 RATES 10 Rate = 0.01*TOT(“Doc”) 20 SAVE rate*TIME

PHREEQC—Reactions From the shelf To the beaker Kinetic reaction Solution 1 Equilibrium phases 5 Surface 21 Kinetic reaction and equilibration

Arsenic in the Central Oklahoma Aquifer Arsenic mostly in confined part of aquifer Arsenic associated with high pH Flow: unconfined to confined back to unconfined

Geochemical Reactions Brine initially fills the aquifer Calcite and Dolomite equilibrium Cation exchange 2NaX + Ca+2 = CaX2 + 2Na+ 2NaX + Mg+2 = MgX2 + 2Na+ Surface complexation Hfo-HAsO4- + OH- = HfoOH + HAsO4-2 Desorption at pH > 8.5

Where we are headed Make a brine Define exchanger Define surface Define recharge water Define minerals in aquifer Simulate inflow of recharge water into brine-filled aquifer

Solution Definition and Speciation Calculations Mg Fe Cl HCO3 Inverse calculations Saturation Indices Speciation calculation Reaction calculations

PHREEQC Data Blocks SOLUTION—Define solution composition SOLUTION_SPREAD—Spreadsheet input for solution composition Other data blocks related to speciation SOLUTION_MASTER_SPECIES—Redox states and gram formula weight SOLUTION_SPECIES—Reaction and log K

Seawater: units are ppm Constituent Value pH pE Temperature Ca Mg Na K Fe Alkalinity as HCO3 Cl SO4 8.22 8.45 25 412.3 1291.8 10768 399.1 .002 141.682 19353 2712

PHREEQC Names and Default Gram Formula Weights Species Default “as” phreeqc.dat/wateq4f.dat Alkalinity CaCO3 C Total carbon HCO3 C(4) TDIC C(-4) Methane CH4 N(5) Nitrate, NO3- N N(-3) Ammonium, NH4+ Si Silica SiO2 PO4 Phosphate P S(6) Sulfate SO4

Solution Data Block

pH, pe, Temperature

Solution Composition Set default units! Select analytes Enter concen-trations Set “As”, special units Click OK when done

Run Speciation Calculation Select files, phreeqc.dat

Exercise: Speciate seawater Use PhreecI to run a speciation calculation for seawater using phreeqc.dat database. DATABASE C:\Program Files\USGS\Phreeqc Interactive 2.12.3\phreeqc.dat # seawater.pqi SOLUTION 1 Seawater temp 25 pH 8.22 pe 8.45 redox pe units ppm density 1 Ca 412.3 Mg 1291.8 Na 10768 K 399.1 Fe .002 Alkalinity 141.682 as HCO3 Cl 19353 S(6) 2712 -water 1 # kg END

What is a speciation calculation? Input: pH pe Concentrations Equations: Mass-balance—sum of the calcium species = total calcium Mass-action—activity of products divided by reactants = constant Activity coefficients—function of ionic strength Output Molalities, activities Saturation indices

pH = 6.3 + log[(HCO3-)/(CO2)] What is pH? pH = 6.3 + log[(HCO3-)/(CO2)] Questions 1. How does the pH change when CO2 degasses during an alkalinity titration? 2. How does pH change when plankton respire CO2? 3. How does pH change when calcite dissolves? Questions 1. CO2 decreases, pH increases. 2. CO2 increases, pH decreases. 3. CaCO3 + CO2 + H2O = Ca+2 + 2HCO3-; CO2 decreases, HCO3- increases, pH increases.

What is pe? Fe+2 = Fe+3 + e- pe = log( [Fe+3]/[Fe+2] ) + 13 HS- + 4H2O = SO4-2 + 9H+ + 8e- pe = log( [SO4-2]/[HS-] ) – 9/8pH + 4.21 N2 + 6H2O = 2:NO3- + 12H+ + 10e- pe = 0.1log( [NO3-]2/[N2] ) –1.2pH + 20.7 pe = 16.9Eh, Eh platinum electrode measurement

Mass-Action Equations H+ + CO3-2 = HCO3-

Mass Balance Calcium mass balance: Catot = (Ca+2) + (CaSO4) + (CaHCO3+) + (CaCO3) + (CaOH+) + (CaHSO4+) In millimoles per kilogram of water: 10.7 = 9.5 + 1.1 + 0.05 + 0.03 + 0.0009 + 6e-8

Activity Coefficients WATEQ activity coefficient Davies activity coefficient Pitzer activity coefficients High ionic strength Limited model

Results of Speciation Calculation Input file: H:\ntc\dk\phreeqc\seawater.pqi Output file: H:\ntc\dk\phreeqc\seawater.pqo Database file: C:\Program Files\USGS\Phreeqc Interactive 2.12.3\phreeqc.dat ------------------ Reading data base. SOLUTION_MASTER_SPECIES SOLUTION_SPECIES PHASES EXCHANGE_MASTER_SPECIES EXCHANGE_SPECIES SURFACE_MASTER_SPECIES SURFACE_SPECIES RATES END ------------------------------------ Reading input data for simulation 1. DATABASE C:\Program Files\USGS\Phreeqc Interactive 2.12.3\phreeqc.dat SOLUTION 1 Seawater temp 25 pH 8.22 pe 8.45 redox pe units ppm density 1 Ca 412.3 Mg 1291.8 Na 10768 K 399.1 Fe .002 Alkalinity 141.682 as HCO3 Cl 19353 S(6) 2712 water 1 # kg ------------------------------------------- Beginning of initial solution calculations. Initial solution 1. Seawater -----------------------------Solution composition------------------------------ Elements Molality Moles Alkalinity 2.406e-003 2.406e-003 Ca 1.066e-002 1.066e-002 Cl 5.657e-001 5.657e-001 Fe 3.711e-008 3.711e-008 K 1.058e-002 1.058e-002 Mg 5.507e-002 5.507e-002 Na 4.854e-001 4.854e-001 S(6) 2.926e-002 2.926e-002 ----------------------------Description of solution---------------------------- pH = 8.220 pe = 8.450 Activity of water = 0.981 Ionic strength = 6.748e-001 Mass of water (kg) = 1.000e+000 Total carbon (mol/kg) = 2.182e-003 Total CO2 (mol/kg) = 2.182e-003 Temperature (deg C) = 25.000 Electrical balance (eq) = 7.967e-004 Percent error, 100*(Cat-|An|)/(Cat+|An|) = 0.07 Iterations = 7 Total H = 1.110144e+002 Total O = 5.562980e+001 ----------------------------Distribution of species---------------------------- Log Log Log Species Molality Activity Molality Activity Gamma OH- 2.674e-006 1.629e-006 -5.573 -5.788 -0.215 H+ 7.981e-009 6.026e-009 -8.098 -8.220 -0.122 H2O 5.551e+001 9.806e-001 1.744 -0.009 0.000 C(4) 2.182e-003 HCO3- 1.516e-003 1.024e-003 -2.819 -2.990 -0.170 MgHCO3+ 2.198e-004 1.642e-004 -3.658 -3.785 -0.127 NaHCO3 1.669e-004 1.950e-004 -3.777 -3.710 0.067 MgCO3 8.924e-005 1.042e-004 -4.049 -3.982 0.067 NaCO3- 6.726e-005 5.026e-005 -4.172 -4.299 -0.127 CaHCO3+ 4.603e-005 3.110e-005 -4.337 -4.507 -0.170 CO3-2 3.826e-005 7.969e-006 -4.417 -5.099 -0.681 CaCO3 2.728e-005 3.187e-005 -4.564 -4.497 0.067 CO2 1.211e-005 1.415e-005 -4.917 -4.849 0.067 FeCO3 1.700e-016 1.985e-016 -15.770 -15.702 0.067 FeHCO3+ 1.423e-016 1.063e-016 -15.847 -15.973 -0.127 Ca 1.066e-002 Ca+2 9.504e-003 2.380e-003 -2.022 -2.623 -0.601 CaSO4 1.083e-003 1.265e-003 -2.965 -2.898 0.067 CaOH+ 8.604e-008 6.429e-008 -7.065 -7.192 -0.127 CaHSO4+ 5.979e-011 4.467e-011 -10.223 -10.350 -0.127 Cl 5.657e-001 Cl- 5.657e-001 3.528e-001 -0.247 -0.452 -0.205 FeCl+ 6.769e-016 5.058e-016 -15.169 -15.296 -0.127 FeCl+2 9.556e-019 2.978e-019 -18.020 -18.526 -0.506 FeCl2+ 6.281e-019 4.693e-019 -18.202 -18.329 -0.127 FeCl3 1.417e-020 1.656e-020 -19.849 -19.781 0.067 Fe(2) 6.007e-015 Fe+2 4.525e-015 1.039e-015 -14.344 -14.984 -0.639 FeSO4 4.213e-016 4.921e-016 -15.375 -15.308 0.067 FeOH+ 7.153e-017 5.345e-017 -16.145 -16.272 -0.127 FeHSO4+ 2.609e-023 1.949e-023 -22.584 -22.710 -0.127 Fe(3) 3.711e-008 Fe(OH)3 2.840e-008 3.318e-008 -7.547 -7.479 0.067 Fe(OH)4- 6.591e-009 4.924e-009 -8.181 -8.308 -0.127 Fe(OH)2+ 2.118e-009 1.583e-009 -8.674 -8.801 -0.127 FeOH+2 9.425e-014 2.937e-014 -13.026 -13.532 -0.506 FeSO4+ 1.093e-018 8.167e-019 -17.961 -18.088 -0.127 Fe+3 3.509e-019 2.795e-020 -18.455 -19.554 -1.099 Fe(SO4)2- 6.371e-020 4.761e-020 -19.196 -19.322 -0.127 Fe2(OH)2+4 2.462e-024 2.322e-026 -23.609 -25.634 -2.025 FeHSO4+2 4.228e-026 1.318e-026 -25.374 -25.880 -0.506 Fe3(OH)4+5 1.122e-029 7.678e-033 -28.950 -32.115 -3.165 H(0) 5.540e-037 H2 2.770e-037 3.236e-037 -36.557 -36.490 0.067 K 1.058e-002 K+ 1.041e-002 6.495e-003 -1.982 -2.187 -0.205 KSO4- 1.627e-004 1.216e-004 -3.789 -3.915 -0.127 KOH 3.137e-009 3.665e-009 -8.503 -8.436 0.067 Mg 5.507e-002 Mg+2 4.742e-002 1.371e-002 -1.324 -1.863 -0.539 MgSO4 7.330e-003 8.562e-003 -2.135 -2.067 0.067 MgOH+ 1.084e-005 8.100e-006 -4.965 -5.092 -0.127 Na 4.854e-001 Na+ 4.791e-001 3.387e-001 -0.320 -0.470 -0.151 NaSO4- 6.053e-003 4.523e-003 -2.218 -2.345 -0.127 NaOH 3.117e-007 3.641e-007 -6.506 -6.439 0.067 O(0) 6.554e-020 O2 3.277e-020 3.828e-020 -19.485 -19.417 0.067 S(6) 2.926e-002 SO4-2 1.463e-002 2.664e-003 -1.835 -2.574 -0.740 HSO4- 2.089e-009 1.561e-009 -8.680 -8.807 -0.127 ------------------------------Saturation indices------------------------------- Phase SI log IAP log KT Anhydrite -0.84 -5.20 -4.36 CaSO4 Aragonite 0.61 -7.72 -8.34 CaCO3 Calcite 0.76 -7.72 -8.48 CaCO3 CO2(g) -3.38 -4.85 -1.47 CO2 Dolomite 2.41 -14.68 -17.09 CaMg(CO3)2 Fe(OH)3(a) 0.19 5.08 4.89 Fe(OH)3 Goethite 6.09 5.09 -1.00 FeOOH Gypsum -0.63 -5.21 -4.58 CaSO4:2H2O H2(g) -33.34 -36.49 -3.15 H2 H2O(g) -1.52 -0.01 1.51 H2O Halite -2.50 -0.92 1.58 NaCl Hematite 14.20 10.19 -4.01 Fe2O3 Jarosite-K -7.52 -16.73 -9.21 KFe3(SO4)2(OH)6 Melanterite -15.41 -17.62 -2.21 FeSO4:7H2O O2(g) -16.52 -19.42 -2.89 O2 Siderite -9.19 -20.08 -10.89 FeCO3 End of simulation. Reading input data for simulation 2. ----------- End of run.

SATURATION INDEX The thermodynamic state of a mineral relative to a solution SI < 0, Mineral should dissolve SI > 0, Mineral should precipitate SI ~ 0, Mineral reacts fast enough to maintain equilibrium Maybe Kinetics Uncertainties

Useful Mineral List Minerals that may react to equilibrium relatively quickly

Other SOLUTION Capabilities Define pe by ratio of redox states—O(0)/H2O, N(5)/N(-3), Fe(3)/Fe(2), S(6)/S(-2) Charge balance—pH or ionic element Adjust element concentration to phase boundary—Al to gibbsite Calculate pH from Alkalinity and C(4) (TDIC) SOLUTION_SPREAD—Spreadsheet format

Modifying the Database Problems with arsenic thermo data Arsenic aqueous model (Nordstrom) not consistent with sorption model (Dzombak and Morel) Competition for surface sites between minor anion and major cations appears unrealistic

Arsenic Thermodynamic Data from Dzombak and Morel SOLUTION_MASTER_SPECIES As H3AsO4 -1.0 74.9216 74.9216 SOLUTION_SPECIES #H3AsO4 primary master species H3AsO4 = H3AsO4 log_k 0.0 #H2AsO4- H3AsO4 = H2AsO4- + H+ log_k -2.243 delta_h -1.69 kcal #HAsO4-2 H3AsO4 = HAsO4-2 + 2H+ log_k -9.001 delta_h -0.92 kcal #AsO4-3 H3AsO4 = AsO4-3 + 3H+ log_k -20.597 delta_h 3.43 kcal SOLUTION_MASTER_SPECIES As H3AsO4 -1.0 74.9216 74.9216 SOLUTION_SPECIES #H3AsO4 primary master species H3AsO4 = H3AsO4 log_k 0.0 #H2AsO4- H3AsO4 = H2AsO4- + H+ log_k -2.243 delta_h -1.69 kcal #HAsO4-2 H3AsO4 = HAsO4-2 + 2H+ log_k -9.001 delta_h -0.92 kcal #AsO4-3 H3AsO4 = AsO4-3 + 3H+ log_k -20.597 delta_h 3.43 kcal

Arsenic Surface Complexation from Dzombak and Morel SURFACE_MASTER_SPECIES Surf SurfOH SURFACE_SPECIES SurfOH = SurfOH log_k 0.0 SurfOH + H+ = SurfOH2+ log_k 7.29 SurfOH = SurfO- + H+ log_k -8.93 SurfOH + AsO4-3 + 3H+ = SurfH2AsO4 + H2O log_k 29.31 SurfOH + AsO4-3 + 2H+ = SurfHAsO4- + H2O log_k 23.51 SurfOH + AsO4-3 = SurfOHAsO4-3 log_k 10.58 SURFACE_MASTER_SPECIES Surf SurfOH SURFACE_SPECIES SurfOH = SurfOH log_k 0.0 SurfOH + H+ = SurfOH2+ log_k 7.29 SurfOH = SurfO- + H+ log_k -8.93 SurfOH + AsO4-3 + 3H+ = SurfH2AsO4 + H2O log_k 29.31 SurfOH + AsO4-3 + 2H+ = SurfHAsO4- + H2O log_k 23.51 SurfOH + AsO4-3 = SurfOHAsO4-3 log_k 10.58

Exercise: Define Arsenic Chemistry Cut and paste As aqueous species defined above Cut and paste As surface complexation defined above Add As to the SOLUTION definition for seawater 0.03 ppb Run speciation # sw_as.pqi SOLUTION_MASTER_SPECIES As H3AsO4 -1.0 74.9216 74.9216 SOLUTION_SPECIES #H3AsO4 primary master species H3AsO4 = H3AsO4 log_k 0.0 #H2AsO4- H3AsO4 = H2AsO4- + H+ log_k -2.243 delta_h -1.69 kcal #HAsO4-2 H3AsO4 = HAsO4-2 + 2H+ log_k -9.001 delta_h -0.92 kcal #AsO4-3 H3AsO4 = AsO4-3 + 3H+ log_k -20.597 delta_h 3.43 kcal SURFACE_MASTER_SPECIES Surf SurfOH SURFACE_SPECIES SurfOH = SurfOH log_k 0.0 SurfOH + H+ = SurfOH2+ log_k 7.29 SurfOH = SurfO- + H+ log_k -8.93 SurfOH + AsO4-3 + 3H+ = SurfH2AsO4 + H2O log_k 29.31 SurfOH + AsO4-3 + 2H+ = SurfHAsO4- + H2O log_k 23.51 SurfOH + AsO4-3 = SurfOHAsO4-3 log_k 10.58 SOLUTION 1 Seawater temp 25 pH 8.22 pe 8.45 redox pe units ppm density 1 Ca 412.3 Mg 1291.8 Na 10768 K 399.1 Fe .002 Alkalinity 141.682 as HCO3 Cl 19353 S(6) 2712 As .03 ppb -water 1 # kg END

Arsenic Speciation Arsenic has been added as a new element Predominant species is HAsO4-2 at pH 8.22 Although not used yet, arsenic sorption has been defined Input file: H:\ntc\dk\phreeqc\sw_as.pqi Output file: H:\ntc\dk\phreeqc\sw_as.pqo Database file: C:\Program Files\USGS\Phreeqc Interactive 2.12.3\phreeqc.dat ------------------ Reading data base. SOLUTION_MASTER_SPECIES SOLUTION_SPECIES PHASES EXCHANGE_MASTER_SPECIES EXCHANGE_SPECIES SURFACE_MASTER_SPECIES SURFACE_SPECIES RATES END ------------------------------------ Reading input data for simulation 1. DATABASE C:\Program Files\USGS\Phreeqc Interactive 2.12.3\phreeqc.dat As H3AsO4 -1.0 74.9216 74.9216 H3AsO4 = H3AsO4 log_k 0.0 H3AsO4 = H2AsO4- + H+ log_k -2.243 delta_h -1.69 kcal H3AsO4 = HAsO4-2 + 2H+ log_k -9.001 delta_h -0.92 kcal H3AsO4 = AsO4-3 + 3H+ log_k -20.597 delta_h 3.43 kcal Surf SurfOH SurfOH = SurfOH log_k 0.0 SurfOH + H+ = SurfOH2+ log_k 7.29 SurfOH = SurfO- + H+ log_k -8.93 SurfOH + AsO4-3 + 3H+ = SurfH2AsO4 + H2O log_k 29.31 SurfOH + AsO4-3 + 2H+ = SurfHAsO4- + H2O log_k 23.51 SurfOH + AsO4-3 = SurfOHAsO4-3 log_k 10.58 SOLUTION 1 Seawater temp 25 pH 8.22 pe 8.45 redox pe units ppm density 1 Ca 412.3 Mg 1291.8 Na 10768 K 399.1 Fe .002 Alkalinity 141.682 as HCO3 Cl 19353 S(6) 2712 As .03 ppb water 1 # kg ------------------------------------------- Beginning of initial solution calculations. Initial solution 1. Seawater -----------------------------Solution composition------------------------------ Elements Molality Moles Alkalinity 2.406e-003 2.406e-003 As 4.150e-010 4.150e-010 Ca 1.066e-002 1.066e-002 Cl 5.657e-001 5.657e-001 Fe 3.711e-008 3.711e-008 K 1.058e-002 1.058e-002 Mg 5.507e-002 5.507e-002 Na 4.854e-001 4.854e-001 S(6) 2.926e-002 2.926e-002 ----------------------------Description of solution---------------------------- pH = 8.220 pe = 8.450 Activity of water = 0.981 Ionic strength = 6.748e-001 Mass of water (kg) = 1.000e+000 Total carbon (mol/kg) = 2.182e-003 Total CO2 (mol/kg) = 2.182e-003 Temperature (deg C) = 25.000 Electrical balance (eq) = 7.967e-004 Percent error, 100*(Cat-|An|)/(Cat+|An|) = 0.07 Iterations = 7 Total H = 1.110144e+002 Total O = 5.562980e+001 ----------------------------Distribution of species---------------------------- Log Log Log Species Molality Activity Molality Activity Gamma OH- 2.674e-006 1.629e-006 -5.573 -5.788 -0.215 H+ 7.981e-009 6.026e-009 -8.098 -8.220 -0.122 H2O 5.551e+001 9.806e-001 1.744 -0.009 0.000 As 4.150e-010 HAsO4-2 4.084e-010 1.273e-010 -9.389 -9.895 -0.506 H2AsO4- 5.879e-012 4.392e-012 -11.231 -11.357 -0.127 AsO4-3 7.378e-013 5.354e-014 -12.132 -13.271 -1.139 H3AsO4 3.965e-018 4.631e-018 -17.402 -17.334 0.067 C(4) 2.182e-003 HCO3- 1.516e-003 1.024e-003 -2.819 -2.990 -0.170 MgHCO3+ 2.198e-004 1.642e-004 -3.658 -3.785 -0.127 NaHCO3 1.669e-004 1.950e-004 -3.777 -3.710 0.067 MgCO3 8.924e-005 1.042e-004 -4.049 -3.982 0.067 NaCO3- 6.726e-005 5.026e-005 -4.172 -4.299 -0.127 CaHCO3+ 4.603e-005 3.110e-005 -4.337 -4.507 -0.170 CO3-2 3.826e-005 7.969e-006 -4.417 -5.099 -0.681 CaCO3 2.728e-005 3.187e-005 -4.564 -4.497 0.067 CO2 1.211e-005 1.415e-005 -4.917 -4.849 0.067 FeCO3 1.700e-016 1.985e-016 -15.770 -15.702 0.067 FeHCO3+ 1.423e-016 1.063e-016 -15.847 -15.973 -0.127 Ca 1.066e-002 Ca+2 9.504e-003 2.380e-003 -2.022 -2.623 -0.601 CaSO4 1.083e-003 1.265e-003 -2.965 -2.898 0.067 CaOH+ 8.604e-008 6.429e-008 -7.065 -7.192 -0.127 CaHSO4+ 5.979e-011 4.467e-011 -10.223 -10.350 -0.127 Cl 5.657e-001 Cl- 5.657e-001 3.528e-001 -0.247 -0.452 -0.205 FeCl+ 6.769e-016 5.058e-016 -15.169 -15.296 -0.127 FeCl+2 9.556e-019 2.978e-019 -18.020 -18.526 -0.506 FeCl2+ 6.281e-019 4.693e-019 -18.202 -18.329 -0.127 FeCl3 1.417e-020 1.656e-020 -19.849 -19.781 0.067 Fe(2) 6.007e-015 Fe+2 4.525e-015 1.039e-015 -14.344 -14.984 -0.639 FeSO4 4.213e-016 4.921e-016 -15.375 -15.308 0.067 FeOH+ 7.153e-017 5.345e-017 -16.145 -16.272 -0.127 FeHSO4+ 2.609e-023 1.949e-023 -22.584 -22.710 -0.127 Fe(3) 3.711e-008 Fe(OH)3 2.840e-008 3.318e-008 -7.547 -7.479 0.067 Fe(OH)4- 6.591e-009 4.924e-009 -8.181 -8.308 -0.127 Fe(OH)2+ 2.118e-009 1.583e-009 -8.674 -8.801 -0.127 FeOH+2 9.425e-014 2.937e-014 -13.026 -13.532 -0.506 FeSO4+ 1.093e-018 8.167e-019 -17.961 -18.088 -0.127 Fe+3 3.509e-019 2.795e-020 -18.455 -19.554 -1.099 Fe(SO4)2- 6.371e-020 4.761e-020 -19.196 -19.322 -0.127 Fe2(OH)2+4 2.462e-024 2.322e-026 -23.609 -25.634 -2.025 FeHSO4+2 4.228e-026 1.318e-026 -25.374 -25.880 -0.506 Fe3(OH)4+5 1.122e-029 7.678e-033 -28.950 -32.115 -3.165 H(0) 5.540e-037 H2 2.770e-037 3.236e-037 -36.557 -36.490 0.067 K 1.058e-002 K+ 1.041e-002 6.495e-003 -1.982 -2.187 -0.205 KSO4- 1.627e-004 1.216e-004 -3.789 -3.915 -0.127 KOH 3.137e-009 3.665e-009 -8.503 -8.436 0.067 Mg 5.507e-002 Mg+2 4.742e-002 1.371e-002 -1.324 -1.863 -0.539 MgSO4 7.330e-003 8.562e-003 -2.135 -2.067 0.067 MgOH+ 1.084e-005 8.100e-006 -4.965 -5.092 -0.127 Na 4.854e-001 Na+ 4.791e-001 3.387e-001 -0.320 -0.470 -0.151 NaSO4- 6.053e-003 4.523e-003 -2.218 -2.345 -0.127 NaOH 3.117e-007 3.641e-007 -6.506 -6.439 0.067 O(0) 6.554e-020 O2 3.277e-020 3.828e-020 -19.485 -19.417 0.067 S(6) 2.926e-002 SO4-2 1.463e-002 2.664e-003 -1.835 -2.574 -0.740 HSO4- 2.089e-009 1.561e-009 -8.680 -8.807 -0.127 ------------------------------Saturation indices------------------------------- Phase SI log IAP log KT Anhydrite -0.84 -5.20 -4.36 CaSO4 Aragonite 0.61 -7.72 -8.34 CaCO3 Calcite 0.76 -7.72 -8.48 CaCO3 CO2(g) -3.38 -4.85 -1.47 CO2 Dolomite 2.41 -14.68 -17.09 CaMg(CO3)2 Fe(OH)3(a) 0.19 5.08 4.89 Fe(OH)3 Goethite 6.09 5.09 -1.00 FeOOH Gypsum -0.63 -5.21 -4.58 CaSO4:2H2O H2(g) -33.34 -36.49 -3.15 H2 H2O(g) -1.52 -0.01 1.51 H2O Halite -2.50 -0.92 1.58 NaCl Hematite 14.20 10.19 -4.01 Fe2O3 Jarosite-K -7.52 -16.73 -9.21 KFe3(SO4)2(OH)6 Melanterite -15.41 -17.62 -2.21 FeSO4:7H2O O2(g) -16.52 -19.42 -2.89 O2 Siderite -9.19 -20.08 -10.89 FeCO3 End of simulation. Reading input data for simulation 2. ----------- End of run.

Reaction Calculations SOLUTION MIX REACTION EQUILIBRIUM_PHASES EXCHANGE SURFACE KINETICS + EQUILIBRATION REACTOR SOLUTION EQUILIBRIUM_ PHASES EXCHANGE SURFACE KINETICS

EQUILIBRIUM REACTIONS Can be used as PHAST initial conditions SURFACE EXCHANGE SOLID_SOLUTIONS EQUILIBRIUM_PHASES

NON-EQUILIBRIUM REACTIONS REACTION_TEMPERATURE KINETICS (PHAST initial condition)

SAVE and USE Save results of calculations Use previously defined SOLUTIONS, EQUILIBRIUM_PHASES, REACTIONs, etc Use previously SAVEd SOLUTIONS, EQUILBRIUM_PHASES, etc

Reactions Evaporating Seawater

PHREEQC Processing and Output Initial-solution calculation Reaction calculation includes any of the following: Simulation/END EQUILIBRIUM_PHASES 2 SOLUTION 1 END MIX REACTION REACTION_TEMP EQUILIBRIUM_PHASES EXCHANGE SURFACE SOLID_SOLUTION GAS_PHASE KINETICS

Exercise: Evaporate Seawater Append to input file and “save as” END USE solution 1 EQUILIBRIUM_PHASES 1 Halite SI = 0 Alternate formula is H2O Calcite—SI=0, moles=0 Dolomite—SI=0, moles=0 CO2(g)—SI=-1.5, moles=10 Anhydrite—SI=0, moles=0 Gypsum—SI=0, moles=0 SAVE solution 1 # sw_evap.pqi SOLUTION_MASTER_SPECIES As H3AsO4 -1.0 74.9216 74.9216 SOLUTION_SPECIES #H3AsO4 primary master species H3AsO4 = H3AsO4 log_k 0.0 #H2AsO4- H3AsO4 = H2AsO4- + H+ log_k -2.243 delta_h -1.69 kcal #HAsO4-2 H3AsO4 = HAsO4-2 + 2H+ log_k -9.001 delta_h -0.92 kcal #AsO4-3 H3AsO4 = AsO4-3 + 3H+ log_k -20.597 delta_h 3.43 kcal SURFACE_MASTER_SPECIES Surf SurfOH SURFACE_SPECIES SurfOH = SurfOH log_k 0.0 SurfOH + H+ = SurfOH2+ log_k 7.29 SurfOH = SurfO- + H+ log_k -8.93 SurfOH + AsO4-3 + 3H+ = SurfH2AsO4 + H2O log_k 29.31 SurfOH + AsO4-3 + 2H+ = SurfHAsO4- + H2O log_k 23.51 SurfOH + AsO4-3 = SurfOHAsO4-3 log_k 10.58 SOLUTION 1 Seawater temp 25 pH 8.22 pe 8.45 redox pe units ppm density 1 Ca 412.3 Mg 1291.8 Na 10768 K 399.1 Fe .002 Alkalinity 141.682 as HCO3 Cl 19353 S(6) 2712 As .03 ppb -water 1 # kg END USE solution 1 EQUILIBRIUM_PHASES Halite 0 H2O Dolomite 0 0 Calcite 0 10 Gypsum 0 0 Anhydrite 0 0 CO2(g) -1.5 SAVE solution 1

Exercise: Evaporate Seawater How much water remains? What is the concentration of Na, Cl? Input file: H:\ntc\dk\phreeqc\sw_evap.pqi Output file: H:\ntc\dk\phreeqc\sw_evap.pqo Database file: C:\Program Files\USGS\Phreeqc Interactive 2.12.3\phreeqc.dat ------------------ Reading data base. SOLUTION_MASTER_SPECIES SOLUTION_SPECIES PHASES EXCHANGE_MASTER_SPECIES EXCHANGE_SPECIES SURFACE_MASTER_SPECIES SURFACE_SPECIES RATES END ------------------------------------ Reading input data for simulation 1. DATABASE C:\Program Files\USGS\Phreeqc Interactive 2.12.3\phreeqc.dat As H3AsO4 -1.0 74.9216 74.9216 H3AsO4 = H3AsO4 log_k 0.0 H3AsO4 = H2AsO4- + H+ log_k -2.243 delta_h -1.69 kcal H3AsO4 = HAsO4-2 + 2H+ log_k -9.001 delta_h -0.92 kcal H3AsO4 = AsO4-3 + 3H+ log_k -20.597 delta_h 3.43 kcal Surf SurfOH SurfOH = SurfOH log_k 0.0 SurfOH + H+ = SurfOH2+ log_k 7.29 SurfOH = SurfO- + H+ log_k -8.93 SurfOH + AsO4-3 + 3H+ = SurfH2AsO4 + H2O log_k 29.31 SurfOH + AsO4-3 + 2H+ = SurfHAsO4- + H2O log_k 23.51 SurfOH + AsO4-3 = SurfOHAsO4-3 log_k 10.58 SOLUTION 1 Seawater temp 25 pH 8.22 pe 8.45 redox pe units ppm density 1 Ca 412.3 Mg 1291.8 Na 10768 K 399.1 Fe .002 Alkalinity 141.682 as HCO3 Cl 19353 S(6) 2712 As .03 ppb water 1 # kg ------------------------------------------- Beginning of initial solution calculations. Initial solution 1. Seawater -----------------------------Solution composition------------------------------ Elements Molality Moles Alkalinity 2.406e-003 2.406e-003 As 4.150e-010 4.150e-010 Ca 1.066e-002 1.066e-002 Cl 5.657e-001 5.657e-001 Fe 3.711e-008 3.711e-008 K 1.058e-002 1.058e-002 Mg 5.507e-002 5.507e-002 Na 4.854e-001 4.854e-001 S(6) 2.926e-002 2.926e-002 ----------------------------Description of solution---------------------------- pH = 8.220 pe = 8.450 Activity of water = 0.981 Ionic strength = 6.748e-001 Mass of water (kg) = 1.000e+000 Total carbon (mol/kg) = 2.182e-003 Total CO2 (mol/kg) = 2.182e-003 Temperature (deg C) = 25.000 Electrical balance (eq) = 7.967e-004 Percent error, 100*(Cat-|An|)/(Cat+|An|) = 0.07 Iterations = 7 Total H = 1.110144e+002 Total O = 5.562980e+001 ----------------------------Distribution of species---------------------------- Log Log Log Species Molality Activity Molality Activity Gamma OH- 2.674e-006 1.629e-006 -5.573 -5.788 -0.215 H+ 7.981e-009 6.026e-009 -8.098 -8.220 -0.122 H2O 5.551e+001 9.806e-001 1.744 -0.009 0.000 As 4.150e-010 HAsO4-2 4.084e-010 1.273e-010 -9.389 -9.895 -0.506 H2AsO4- 5.879e-012 4.392e-012 -11.231 -11.357 -0.127 AsO4-3 7.378e-013 5.354e-014 -12.132 -13.271 -1.139 H3AsO4 3.965e-018 4.631e-018 -17.402 -17.334 0.067 C(4) 2.182e-003 HCO3- 1.516e-003 1.024e-003 -2.819 -2.990 -0.170 MgHCO3+ 2.198e-004 1.642e-004 -3.658 -3.785 -0.127 NaHCO3 1.669e-004 1.950e-004 -3.777 -3.710 0.067 MgCO3 8.924e-005 1.042e-004 -4.049 -3.982 0.067 NaCO3- 6.726e-005 5.026e-005 -4.172 -4.299 -0.127 CaHCO3+ 4.603e-005 3.110e-005 -4.337 -4.507 -0.170 CO3-2 3.826e-005 7.969e-006 -4.417 -5.099 -0.681 CaCO3 2.728e-005 3.187e-005 -4.564 -4.497 0.067 CO2 1.211e-005 1.415e-005 -4.917 -4.849 0.067 FeCO3 1.700e-016 1.985e-016 -15.770 -15.702 0.067 FeHCO3+ 1.423e-016 1.063e-016 -15.847 -15.973 -0.127 Ca 1.066e-002 Ca+2 9.504e-003 2.380e-003 -2.022 -2.623 -0.601 CaSO4 1.083e-003 1.265e-003 -2.965 -2.898 0.067 CaOH+ 8.604e-008 6.429e-008 -7.065 -7.192 -0.127 CaHSO4+ 5.979e-011 4.467e-011 -10.223 -10.350 -0.127 Cl 5.657e-001 Cl- 5.657e-001 3.528e-001 -0.247 -0.452 -0.205 FeCl+ 6.769e-016 5.058e-016 -15.169 -15.296 -0.127 FeCl+2 9.556e-019 2.978e-019 -18.020 -18.526 -0.506 FeCl2+ 6.281e-019 4.693e-019 -18.202 -18.329 -0.127 FeCl3 1.417e-020 1.656e-020 -19.849 -19.781 0.067 Fe(2) 6.007e-015 Fe+2 4.525e-015 1.039e-015 -14.344 -14.984 -0.639 FeSO4 4.213e-016 4.921e-016 -15.375 -15.308 0.067 FeOH+ 7.153e-017 5.345e-017 -16.145 -16.272 -0.127 FeHSO4+ 2.609e-023 1.949e-023 -22.584 -22.710 -0.127 Fe(3) 3.711e-008 Fe(OH)3 2.840e-008 3.318e-008 -7.547 -7.479 0.067 Fe(OH)4- 6.591e-009 4.924e-009 -8.181 -8.308 -0.127 Fe(OH)2+ 2.118e-009 1.583e-009 -8.674 -8.801 -0.127 FeOH+2 9.425e-014 2.937e-014 -13.026 -13.532 -0.506 FeSO4+ 1.093e-018 8.167e-019 -17.961 -18.088 -0.127 Fe+3 3.509e-019 2.795e-020 -18.455 -19.554 -1.099 Fe(SO4)2- 6.371e-020 4.761e-020 -19.196 -19.322 -0.127 Fe2(OH)2+4 2.462e-024 2.322e-026 -23.609 -25.634 -2.025 FeHSO4+2 4.228e-026 1.318e-026 -25.374 -25.880 -0.506 Fe3(OH)4+5 1.122e-029 7.678e-033 -28.950 -32.115 -3.165 H(0) 5.540e-037 H2 2.770e-037 3.236e-037 -36.557 -36.490 0.067 K 1.058e-002 K+ 1.041e-002 6.495e-003 -1.982 -2.187 -0.205 KSO4- 1.627e-004 1.216e-004 -3.789 -3.915 -0.127 KOH 3.137e-009 3.665e-009 -8.503 -8.436 0.067 Mg 5.507e-002 Mg+2 4.742e-002 1.371e-002 -1.324 -1.863 -0.539 MgSO4 7.330e-003 8.562e-003 -2.135 -2.067 0.067 MgOH+ 1.084e-005 8.100e-006 -4.965 -5.092 -0.127 Na 4.854e-001 Na+ 4.791e-001 3.387e-001 -0.320 -0.470 -0.151 NaSO4- 6.053e-003 4.523e-003 -2.218 -2.345 -0.127 NaOH 3.117e-007 3.641e-007 -6.506 -6.439 0.067 O(0) 6.554e-020 O2 3.277e-020 3.828e-020 -19.485 -19.417 0.067 S(6) 2.926e-002 SO4-2 1.463e-002 2.664e-003 -1.835 -2.574 -0.740 HSO4- 2.089e-009 1.561e-009 -8.680 -8.807 -0.127 ------------------------------Saturation indices------------------------------- Phase SI log IAP log KT Anhydrite -0.84 -5.20 -4.36 CaSO4 Aragonite 0.61 -7.72 -8.34 CaCO3 Calcite 0.76 -7.72 -8.48 CaCO3 CO2(g) -3.38 -4.85 -1.47 CO2 Dolomite 2.41 -14.68 -17.09 CaMg(CO3)2 Fe(OH)3(a) 0.19 5.08 4.89 Fe(OH)3 Goethite 6.09 5.09 -1.00 FeOOH Gypsum -0.63 -5.21 -4.58 CaSO4:2H2O H2(g) -33.34 -36.49 -3.15 H2 H2O(g) -1.52 -0.01 1.51 H2O Halite -2.50 -0.92 1.58 NaCl Hematite 14.20 10.19 -4.01 Fe2O3 Jarosite-K -7.52 -16.73 -9.21 KFe3(SO4)2(OH)6 Melanterite -15.41 -17.62 -2.21 FeSO4:7H2O O2(g) -16.52 -19.42 -2.89 O2 Siderite -9.19 -20.08 -10.89 FeCO3 End of simulation. Reading input data for simulation 2. USE solution 1 EQUILIBRIUM_PHASES Halite 0 H2O Dolomite 0 0 Calcite 0 10 Gypsum 0 0 Anhydrite 0 0 CO2(g) -1.5 SAVE solution 1 ----------------------------------------- Beginning of batch-reaction calculations. Reaction step 1. Using solution 1. Seawater Using pure phase assemblage 1. -------------------------------Phase assemblage-------------------------------- Moles in assemblage Phase SI log IAP log KT Initial Final Delta Anhydrite -0.00 -4.37 -4.36 0.000e+000 0.000e+000 Calcite 0.00 -8.48 -8.48 1.000e+001 9.910e+000-9.037e-002 CO2(g) -1.50 -19.65 -18.15 1.000e+001 1.000e+001 8.232e-004 Dolomite -0.00 -17.09 -17.09 0.000e+000 4.572e-002 4.572e-002 Gypsum 0.00 -4.58 -4.58 0.000e+000 2.875e-002 2.875e-002 Halite 0.00 1.58 1.58 H2O is reactant 1.000e+001 6.073e+001 5.073e+001 As 4.883e-009 4.150e-010 C 3.461e-003 2.942e-004 Ca 3.125e-001 2.656e-002 Cl 6.657e+000 5.657e-001 Fe 4.367e-007 3.711e-008 K 1.245e-001 1.058e-002 Mg 1.100e-001 9.350e-003 Na 5.712e+000 4.854e-001 S 5.972e-003 5.075e-004 pH = 5.814 Charge balance pe = 13.135 Adjusted to redox equilibrium Activity of water = 0.780 Ionic strength = 7.085e+000 Mass of water (kg) = 8.499e-002 Total alkalinity (eq/kg) = 3.251e-003 Total CO2 (mol/kg) = 3.461e-003 Iterations = 19 Total H = 9.434897e+000 Total O = 4.720205e+000 H+ 2.182e-006 1.534e-006 -5.661 -5.814 -0.153 OH- 1.099e-008 5.092e-009 -7.959 -8.293 -0.334 H2O 5.551e+001 7.804e-001 1.744 -0.108 0.000 As 4.883e-009 H2AsO4- 4.877e-009 2.515e-008 -8.312 -7.599 0.712 HAsO4-2 4.048e-012 2.862e-009 -11.393 -8.543 2.849 H3AsO4 1.321e-012 6.752e-012 -11.879 -11.171 0.709 AsO4-3 1.835e-021 4.728e-015 -20.736 -14.325 6.411 C(-4) 0.000e+000 CH4 0.000e+000 0.000e+000 -130.660 -129.952 0.709 C(4) 3.461e-003 CaHCO3+ 2.387e-003 1.383e-003 -2.622 -2.859 -0.237 HCO3- 4.204e-004 2.436e-004 -3.376 -3.613 -0.237 NaHCO3 2.598e-004 1.328e-003 -3.585 -2.877 0.709 CO2 2.106e-004 1.077e-003 -3.676 -2.968 0.709 MgHCO3+ 1.822e-004 9.393e-004 -3.740 -3.027 0.712 CaCO3 1.089e-006 5.565e-006 -5.963 -5.255 0.709 MgCO3 4.581e-007 2.341e-006 -6.339 -5.631 0.709 NaCO3- 2.606e-007 1.344e-006 -6.584 -5.872 0.712 CO3-2 6.607e-008 7.444e-009 -7.180 -8.128 -0.948 FeHCO3+ 1.378e-014 7.106e-014 -13.861 -13.148 0.712 FeCO3 1.019e-016 5.210e-016 -15.992 -15.283 0.709 Ca 3.125e-001 Ca+2 3.085e-001 4.450e-001 -0.511 -0.352 0.159 CaSO4 1.682e-003 8.599e-003 -2.774 -2.066 0.709 CaHSO4+ 1.499e-008 7.729e-008 -7.824 -7.112 0.712 CaOH+ 7.285e-009 3.756e-008 -8.138 -7.425 0.712 Cl 6.657e+000 Cl- 6.657e+000 3.940e+000 0.823 0.596 -0.228 FeCl2+ 1.543e-009 7.955e-009 -8.812 -8.099 0.712 FeCl3 6.132e-010 3.134e-009 -9.212 -8.504 0.709 FeCl+ 3.077e-012 1.587e-011 -11.512 -10.799 0.712 FeCl+2 6.395e-013 4.520e-010 -12.194 -9.345 2.849 Fe(2) 2.466e-011 Fe+2 2.156e-011 2.918e-012 -10.666 -11.535 -0.869 FeSO4 9.831e-015 5.025e-014 -14.007 -13.299 0.709 FeOH+ 9.101e-017 4.693e-016 -16.041 -15.329 0.712 FeHSO4+ 9.828e-020 5.068e-019 -19.008 -18.295 0.712 Fe(HS)2 0.000e+000 0.000e+000 -257.967 -257.258 0.709 Fe(HS)3- 0.000e+000 0.000e+000 -383.270 -382.558 0.712 Fe(3) 4.367e-007 Fe(OH)2+ 4.075e-007 2.101e-006 -6.390 -5.678 0.712 Fe(OH)3 2.693e-008 1.377e-007 -7.570 -6.861 0.709 Fe+3 9.035e-011 3.799e-012 -10.044 -11.420 -1.376 FeOH+2 1.765e-011 1.247e-008 -10.753 -7.904 2.849 Fe(OH)4- 1.238e-011 6.386e-011 -10.907 -10.195 0.712 FeSO4+ 7.823e-013 4.034e-012 -12.107 -11.394 0.712 Fe(SO4)2- 1.658e-015 8.547e-015 -14.781 -14.068 0.712 FeHSO4+2 2.345e-020 1.657e-017 -19.630 -16.781 2.849 Fe2(OH)2+4 1.678e-026 4.188e-015 -25.775 -14.378 11.397 Fe3(OH)4+5 2.859e-036 1.838e-018 -35.544 -17.736 17.808 H(0) 0.000e+000 H2 0.000e+000 0.000e+000 -41.756 -41.047 0.709 K 1.245e-001 K+ 1.245e-001 7.366e-002 -0.905 -1.133 -0.228 KSO4- 9.722e-006 5.013e-005 -5.012 -4.300 0.712 KOH 2.542e-011 1.299e-010 -10.595 -9.886 0.709 Mg 1.100e-001 Mg+2 1.084e-001 3.296e-001 -0.965 -0.482 0.483 MgSO4 1.464e-003 7.484e-003 -2.834 -2.126 0.709 MgOH+ 1.181e-007 6.087e-007 -6.928 -6.216 0.712 Na 5.712e+000 Na+ 5.710e+000 9.694e+000 0.757 0.986 0.230 NaSO4- 9.126e-004 4.705e-003 -3.040 -2.327 0.712 NaOH 6.373e-009 3.258e-008 -8.196 -7.487 0.709 O(0) 1.236e-011 O2 6.178e-012 3.158e-011 -11.209 -10.501 0.709 S(-2) 0.000e+000 H2S 0.000e+000 0.000e+000 -126.918 -126.209 0.709 HS- 0.000e+000 0.000e+000 -127.003 -127.337 -0.334 S-2 0.000e+000 0.000e+000 -133.431 -134.441 -1.010 S(6) 5.972e-003 SO4-2 1.903e-003 9.685e-005 -2.721 -4.014 -1.293 HSO4- 2.802e-009 1.445e-008 -8.553 -7.840 0.712 Anhydrite -0.00 -4.37 -4.36 CaSO4 Aragonite -0.14 -8.48 -8.34 CaCO3 Calcite 0.00 -8.48 -8.48 CaCO3 CH4(g) -127.09 -129.95 -2.86 CH4 CO2(g) -1.50 -2.97 -1.47 CO2 Dolomite -0.00 -17.09 -17.09 CaMg(CO3)2 Fe(OH)3(a) 0.81 5.70 4.89 Fe(OH)3 FeS(ppt) -129.14 -133.06 -3.92 FeS Goethite 6.81 5.81 -1.00 FeOOH Gypsum 0.00 -4.58 -4.58 CaSO4:2H2O H2(g) -37.90 -41.05 -3.15 H2 H2O(g) -1.62 -0.11 1.51 H2O H2S(g) -125.21 -126.21 -1.00 H2S Halite 0.00 1.58 1.58 NaCl Hematite 15.73 11.72 -4.01 Fe2O3 Jarosite-K 0.03 -9.18 -9.21 KFe3(SO4)2(OH)6 Mackinawite -128.41 -133.06 -4.65 FeS Melanterite -14.09 -16.30 -2.21 FeSO4:7H2O O2(g) -7.61 -10.50 -2.89 O2 Pyrite -209.83 -228.31 -18.48 FeS2 Siderite -8.77 -19.66 -10.89 FeCO3 Sulfur -93.19 -88.31 4.88 S Reading input data for simulation 3. ----------- End of run.

Exercise: Surface composition in equilibrium with brine Define a SURFACE 1 Equilibrium with solution 1 SurfOH 0.14 moles of sites 600 m2/g 30 g # sw_ex_surf.pqi SOLUTION_MASTER_SPECIES As H3AsO4 -1.0 74.9216 74.9216 SOLUTION_SPECIES #H3AsO4 primary master species H3AsO4 = H3AsO4 log_k 0.0 #H2AsO4- H3AsO4 = H2AsO4- + H+ log_k -2.243 delta_h -1.69 kcal #HAsO4-2 H3AsO4 = HAsO4-2 + 2H+ log_k -9.001 delta_h -0.92 kcal #AsO4-3 H3AsO4 = AsO4-3 + 3H+ log_k -20.597 delta_h 3.43 kcal SURFACE_MASTER_SPECIES Surf SurfOH SURFACE_SPECIES SurfOH = SurfOH log_k 0.0 SurfOH + H+ = SurfOH2+ log_k 7.29 SurfOH = SurfO- + H+ log_k -8.93 SurfOH + AsO4-3 + 3H+ = SurfH2AsO4 + H2O log_k 29.31 SurfOH + AsO4-3 + 2H+ = SurfHAsO4- + H2O log_k 23.51 SurfOH + AsO4-3 = SurfOHAsO4-3 log_k 10.58 SOLUTION 1 Seawater temp 25 pH 8.22 pe 8.45 redox pe units ppm density 1 Ca 412.3 Mg 1291.8 Na 10768 K 399.1 Fe .002 Alkalinity 141.682 as HCO3 Cl 19353 S(6) 2712 As .03 ppb -water 1 # kg END USE solution 1 EQUILIBRIUM_PHASES Halite 0 H2O Dolomite 0 0 Calcite 0 10 Gypsum 0 0 Anhydrite 0 0 CO2(g) -1.5 SAVE solution 1 SURFACE 1 Surface in equilibrium with brine -equilibrate with solution 1 Surf 0.14 600 30 EXCHANGE 1 X 0.4

Exercise: Exchange composition in equilibrium with brine Define EXCHANGE 1 Equilibrium with solution 1 0.4 moles of exchange sites Input file: H:\ntc\dk\phreeqc\sw_ex_surf.pqi Output file: H:\ntc\dk\phreeqc\sw_ex_surf.pqo Database file: C:\Program Files\USGS\Phreeqc Interactive 2.12.3\phreeqc.dat ------------------ Reading data base. SOLUTION_MASTER_SPECIES SOLUTION_SPECIES PHASES EXCHANGE_MASTER_SPECIES EXCHANGE_SPECIES SURFACE_MASTER_SPECIES SURFACE_SPECIES RATES END ------------------------------------ Reading input data for simulation 1. DATABASE C:\Program Files\USGS\Phreeqc Interactive 2.12.3\phreeqc.dat As H3AsO4 -1.0 74.9216 74.9216 H3AsO4 = H3AsO4 log_k 0.0 H3AsO4 = H2AsO4- + H+ log_k -2.243 delta_h -1.69 kcal H3AsO4 = HAsO4-2 + 2H+ log_k -9.001 delta_h -0.92 kcal H3AsO4 = AsO4-3 + 3H+ log_k -20.597 delta_h 3.43 kcal Surf SurfOH SurfOH = SurfOH log_k 0.0 SurfOH + H+ = SurfOH2+ log_k 7.29 SurfOH = SurfO- + H+ log_k -8.93 SurfOH + AsO4-3 + 3H+ = SurfH2AsO4 + H2O log_k 29.31 SurfOH + AsO4-3 + 2H+ = SurfHAsO4- + H2O log_k 23.51 SurfOH + AsO4-3 = SurfOHAsO4-3 log_k 10.58 SOLUTION 1 Seawater temp 25 pH 8.22 pe 8.45 redox pe units ppm density 1 Ca 412.3 Mg 1291.8 Na 10768 K 399.1 Fe .002 Alkalinity 141.682 as HCO3 Cl 19353 S(6) 2712 As .03 ppb water 1 # kg ------------------------------------------- Beginning of initial solution calculations. Initial solution 1. Seawater -----------------------------Solution composition------------------------------ Elements Molality Moles Alkalinity 2.406e-003 2.406e-003 As 4.150e-010 4.150e-010 Ca 1.066e-002 1.066e-002 Cl 5.657e-001 5.657e-001 Fe 3.711e-008 3.711e-008 K 1.058e-002 1.058e-002 Mg 5.507e-002 5.507e-002 Na 4.854e-001 4.854e-001 S(6) 2.926e-002 2.926e-002 ----------------------------Description of solution---------------------------- pH = 8.220 pe = 8.450 Activity of water = 0.981 Ionic strength = 6.748e-001 Mass of water (kg) = 1.000e+000 Total carbon (mol/kg) = 2.182e-003 Total CO2 (mol/kg) = 2.182e-003 Temperature (deg C) = 25.000 Electrical balance (eq) = 7.967e-004 Percent error, 100*(Cat-|An|)/(Cat+|An|) = 0.07 Iterations = 7 Total H = 1.110144e+002 Total O = 5.562980e+001 ----------------------------Distribution of species---------------------------- Log Log Log Species Molality Activity Molality Activity Gamma OH- 2.674e-006 1.629e-006 -5.573 -5.788 -0.215 H+ 7.981e-009 6.026e-009 -8.098 -8.220 -0.122 H2O 5.551e+001 9.806e-001 1.744 -0.009 0.000 As 4.150e-010 HAsO4-2 4.084e-010 1.273e-010 -9.389 -9.895 -0.506 H2AsO4- 5.879e-012 4.392e-012 -11.231 -11.357 -0.127 AsO4-3 7.378e-013 5.354e-014 -12.132 -13.271 -1.139 H3AsO4 3.965e-018 4.631e-018 -17.402 -17.334 0.067 C(4) 2.182e-003 HCO3- 1.516e-003 1.024e-003 -2.819 -2.990 -0.170 MgHCO3+ 2.198e-004 1.642e-004 -3.658 -3.785 -0.127 NaHCO3 1.669e-004 1.950e-004 -3.777 -3.710 0.067 MgCO3 8.924e-005 1.042e-004 -4.049 -3.982 0.067 NaCO3- 6.726e-005 5.026e-005 -4.172 -4.299 -0.127 CaHCO3+ 4.603e-005 3.110e-005 -4.337 -4.507 -0.170 CO3-2 3.826e-005 7.969e-006 -4.417 -5.099 -0.681 CaCO3 2.728e-005 3.187e-005 -4.564 -4.497 0.067 CO2 1.211e-005 1.415e-005 -4.917 -4.849 0.067 FeCO3 1.700e-016 1.985e-016 -15.770 -15.702 0.067 FeHCO3+ 1.423e-016 1.063e-016 -15.847 -15.973 -0.127 Ca 1.066e-002 Ca+2 9.504e-003 2.380e-003 -2.022 -2.623 -0.601 CaSO4 1.083e-003 1.265e-003 -2.965 -2.898 0.067 CaOH+ 8.604e-008 6.429e-008 -7.065 -7.192 -0.127 CaHSO4+ 5.979e-011 4.467e-011 -10.223 -10.350 -0.127 Cl 5.657e-001 Cl- 5.657e-001 3.528e-001 -0.247 -0.452 -0.205 FeCl+ 6.769e-016 5.058e-016 -15.169 -15.296 -0.127 FeCl+2 9.556e-019 2.978e-019 -18.020 -18.526 -0.506 FeCl2+ 6.281e-019 4.693e-019 -18.202 -18.329 -0.127 FeCl3 1.417e-020 1.656e-020 -19.849 -19.781 0.067 Fe(2) 6.007e-015 Fe+2 4.525e-015 1.039e-015 -14.344 -14.984 -0.639 FeSO4 4.213e-016 4.921e-016 -15.375 -15.308 0.067 FeOH+ 7.153e-017 5.345e-017 -16.145 -16.272 -0.127 FeHSO4+ 2.609e-023 1.949e-023 -22.584 -22.710 -0.127 Fe(3) 3.711e-008 Fe(OH)3 2.840e-008 3.318e-008 -7.547 -7.479 0.067 Fe(OH)4- 6.591e-009 4.924e-009 -8.181 -8.308 -0.127 Fe(OH)2+ 2.118e-009 1.583e-009 -8.674 -8.801 -0.127 FeOH+2 9.425e-014 2.937e-014 -13.026 -13.532 -0.506 FeSO4+ 1.093e-018 8.167e-019 -17.961 -18.088 -0.127 Fe+3 3.509e-019 2.795e-020 -18.455 -19.554 -1.099 Fe(SO4)2- 6.371e-020 4.761e-020 -19.196 -19.322 -0.127 Fe2(OH)2+4 2.462e-024 2.322e-026 -23.609 -25.634 -2.025 FeHSO4+2 4.228e-026 1.318e-026 -25.374 -25.880 -0.506 Fe3(OH)4+5 1.122e-029 7.678e-033 -28.950 -32.115 -3.165 H(0) 5.540e-037 H2 2.770e-037 3.236e-037 -36.557 -36.490 0.067 K 1.058e-002 K+ 1.041e-002 6.495e-003 -1.982 -2.187 -0.205 KSO4- 1.627e-004 1.216e-004 -3.789 -3.915 -0.127 KOH 3.137e-009 3.665e-009 -8.503 -8.436 0.067 Mg 5.507e-002 Mg+2 4.742e-002 1.371e-002 -1.324 -1.863 -0.539 MgSO4 7.330e-003 8.562e-003 -2.135 -2.067 0.067 MgOH+ 1.084e-005 8.100e-006 -4.965 -5.092 -0.127 Na 4.854e-001 Na+ 4.791e-001 3.387e-001 -0.320 -0.470 -0.151 NaSO4- 6.053e-003 4.523e-003 -2.218 -2.345 -0.127 NaOH 3.117e-007 3.641e-007 -6.506 -6.439 0.067 O(0) 6.554e-020 O2 3.277e-020 3.828e-020 -19.485 -19.417 0.067 S(6) 2.926e-002 SO4-2 1.463e-002 2.664e-003 -1.835 -2.574 -0.740 HSO4- 2.089e-009 1.561e-009 -8.680 -8.807 -0.127 ------------------------------Saturation indices------------------------------- Phase SI log IAP log KT Anhydrite -0.84 -5.20 -4.36 CaSO4 Aragonite 0.61 -7.72 -8.34 CaCO3 Calcite 0.76 -7.72 -8.48 CaCO3 CO2(g) -3.38 -4.85 -1.47 CO2 Dolomite 2.41 -14.68 -17.09 CaMg(CO3)2 Fe(OH)3(a) 0.19 5.08 4.89 Fe(OH)3 Goethite 6.09 5.09 -1.00 FeOOH Gypsum -0.63 -5.21 -4.58 CaSO4:2H2O H2(g) -33.34 -36.49 -3.15 H2 H2O(g) -1.52 -0.01 1.51 H2O Halite -2.50 -0.92 1.58 NaCl Hematite 14.20 10.19 -4.01 Fe2O3 Jarosite-K -7.52 -16.73 -9.21 KFe3(SO4)2(OH)6 Melanterite -15.41 -17.62 -2.21 FeSO4:7H2O O2(g) -16.52 -19.42 -2.89 O2 Siderite -9.19 -20.08 -10.89 FeCO3 End of simulation. Reading input data for simulation 2. USE solution 1 EQUILIBRIUM_PHASES Halite 0 H2O Dolomite 0 0 Calcite 0 10 Gypsum 0 0 Anhydrite 0 0 CO2(g) -1.5 SAVE solution 1 ----------------------------------------- Beginning of batch-reaction calculations. Reaction step 1. Using solution 1. Seawater Using pure phase assemblage 1. -------------------------------Phase assemblage-------------------------------- Moles in assemblage Phase SI log IAP log KT Initial Final Delta Anhydrite -0.00 -4.37 -4.36 0.000e+000 0.000e+000 Calcite 0.00 -8.48 -8.48 1.000e+001 9.910e+000-9.037e-002 CO2(g) -1.50 -19.65 -18.15 1.000e+001 1.000e+001 8.232e-004 Dolomite -0.00 -17.09 -17.09 0.000e+000 4.572e-002 4.572e-002 Gypsum 0.00 -4.58 -4.58 0.000e+000 2.875e-002 2.875e-002 Halite 0.00 1.58 1.58 H2O is reactant 1.000e+001 6.073e+001 5.073e+001 As 4.883e-009 4.150e-010 C 3.461e-003 2.942e-004 Ca 3.125e-001 2.656e-002 Cl 6.657e+000 5.657e-001 Fe 4.367e-007 3.711e-008 K 1.245e-001 1.058e-002 Mg 1.100e-001 9.350e-003 Na 5.712e+000 4.854e-001 S 5.972e-003 5.075e-004 pH = 5.814 Charge balance pe = 13.135 Adjusted to redox equilibrium Activity of water = 0.780 Ionic strength = 7.085e+000 Mass of water (kg) = 8.499e-002 Total alkalinity (eq/kg) = 3.251e-003 Total CO2 (mol/kg) = 3.461e-003 Iterations = 19 Total H = 9.434897e+000 Total O = 4.720205e+000 H+ 2.182e-006 1.534e-006 -5.661 -5.814 -0.153 OH- 1.099e-008 5.092e-009 -7.959 -8.293 -0.334 H2O 5.551e+001 7.804e-001 1.744 -0.108 0.000 As 4.883e-009 H2AsO4- 4.877e-009 2.515e-008 -8.312 -7.599 0.712 HAsO4-2 4.048e-012 2.862e-009 -11.393 -8.543 2.849 H3AsO4 1.321e-012 6.752e-012 -11.879 -11.171 0.709 AsO4-3 1.835e-021 4.728e-015 -20.736 -14.325 6.411 C(-4) 0.000e+000 CH4 0.000e+000 0.000e+000 -130.660 -129.952 0.709 C(4) 3.461e-003 CaHCO3+ 2.387e-003 1.383e-003 -2.622 -2.859 -0.237 HCO3- 4.204e-004 2.436e-004 -3.376 -3.613 -0.237 NaHCO3 2.598e-004 1.328e-003 -3.585 -2.877 0.709 CO2 2.106e-004 1.077e-003 -3.676 -2.968 0.709 MgHCO3+ 1.822e-004 9.393e-004 -3.740 -3.027 0.712 CaCO3 1.089e-006 5.565e-006 -5.963 -5.255 0.709 MgCO3 4.581e-007 2.341e-006 -6.339 -5.631 0.709 NaCO3- 2.606e-007 1.344e-006 -6.584 -5.872 0.712 CO3-2 6.607e-008 7.444e-009 -7.180 -8.128 -0.948 FeHCO3+ 1.378e-014 7.106e-014 -13.861 -13.148 0.712 FeCO3 1.019e-016 5.210e-016 -15.992 -15.283 0.709 Ca 3.125e-001 Ca+2 3.085e-001 4.450e-001 -0.511 -0.352 0.159 CaSO4 1.682e-003 8.599e-003 -2.774 -2.066 0.709 CaHSO4+ 1.499e-008 7.729e-008 -7.824 -7.112 0.712 CaOH+ 7.285e-009 3.756e-008 -8.138 -7.425 0.712 Cl 6.657e+000 Cl- 6.657e+000 3.940e+000 0.823 0.596 -0.228 FeCl2+ 1.543e-009 7.955e-009 -8.812 -8.099 0.712 FeCl3 6.132e-010 3.134e-009 -9.212 -8.504 0.709 FeCl+ 3.077e-012 1.587e-011 -11.512 -10.799 0.712 FeCl+2 6.395e-013 4.520e-010 -12.194 -9.345 2.849 Fe(2) 2.466e-011 Fe+2 2.156e-011 2.918e-012 -10.666 -11.535 -0.869 FeSO4 9.831e-015 5.025e-014 -14.007 -13.299 0.709 FeOH+ 9.101e-017 4.693e-016 -16.041 -15.329 0.712 FeHSO4+ 9.828e-020 5.068e-019 -19.008 -18.295 0.712 Fe(HS)2 0.000e+000 0.000e+000 -257.967 -257.258 0.709 Fe(HS)3- 0.000e+000 0.000e+000 -383.270 -382.558 0.712 Fe(3) 4.367e-007 Fe(OH)2+ 4.075e-007 2.101e-006 -6.390 -5.678 0.712 Fe(OH)3 2.693e-008 1.377e-007 -7.570 -6.861 0.709 Fe+3 9.035e-011 3.799e-012 -10.044 -11.420 -1.376 FeOH+2 1.765e-011 1.247e-008 -10.753 -7.904 2.849 Fe(OH)4- 1.238e-011 6.386e-011 -10.907 -10.195 0.712 FeSO4+ 7.823e-013 4.034e-012 -12.107 -11.394 0.712 Fe(SO4)2- 1.658e-015 8.547e-015 -14.781 -14.068 0.712 FeHSO4+2 2.345e-020 1.657e-017 -19.630 -16.781 2.849 Fe2(OH)2+4 1.678e-026 4.188e-015 -25.775 -14.378 11.397 Fe3(OH)4+5 2.859e-036 1.838e-018 -35.544 -17.736 17.808 H(0) 0.000e+000 H2 0.000e+000 0.000e+000 -41.756 -41.047 0.709 K 1.245e-001 K+ 1.245e-001 7.366e-002 -0.905 -1.133 -0.228 KSO4- 9.722e-006 5.013e-005 -5.012 -4.300 0.712 KOH 2.542e-011 1.299e-010 -10.595 -9.886 0.709 Mg 1.100e-001 Mg+2 1.084e-001 3.296e-001 -0.965 -0.482 0.483 MgSO4 1.464e-003 7.484e-003 -2.834 -2.126 0.709 MgOH+ 1.181e-007 6.087e-007 -6.928 -6.216 0.712 Na 5.712e+000 Na+ 5.710e+000 9.694e+000 0.757 0.986 0.230 NaSO4- 9.126e-004 4.705e-003 -3.040 -2.327 0.712 NaOH 6.373e-009 3.258e-008 -8.196 -7.487 0.709 O(0) 1.236e-011 O2 6.178e-012 3.158e-011 -11.209 -10.501 0.709 S(-2) 0.000e+000 H2S 0.000e+000 0.000e+000 -126.918 -126.209 0.709 HS- 0.000e+000 0.000e+000 -127.003 -127.337 -0.334 S-2 0.000e+000 0.000e+000 -133.431 -134.441 -1.010 S(6) 5.972e-003 SO4-2 1.903e-003 9.685e-005 -2.721 -4.014 -1.293 HSO4- 2.802e-009 1.445e-008 -8.553 -7.840 0.712 Anhydrite -0.00 -4.37 -4.36 CaSO4 Aragonite -0.14 -8.48 -8.34 CaCO3 Calcite 0.00 -8.48 -8.48 CaCO3 CH4(g) -127.09 -129.95 -2.86 CH4 CO2(g) -1.50 -2.97 -1.47 CO2 Dolomite -0.00 -17.09 -17.09 CaMg(CO3)2 Fe(OH)3(a) 0.81 5.70 4.89 Fe(OH)3 FeS(ppt) -129.14 -133.06 -3.92 FeS Goethite 6.81 5.81 -1.00 FeOOH Gypsum 0.00 -4.58 -4.58 CaSO4:2H2O H2(g) -37.90 -41.05 -3.15 H2 H2O(g) -1.62 -0.11 1.51 H2O H2S(g) -125.21 -126.21 -1.00 H2S Halite 0.00 1.58 1.58 NaCl Hematite 15.73 11.72 -4.01 Fe2O3 Jarosite-K 0.03 -9.18 -9.21 KFe3(SO4)2(OH)6 Mackinawite -128.41 -133.06 -4.65 FeS Melanterite -14.09 -16.30 -2.21 FeSO4:7H2O O2(g) -7.61 -10.50 -2.89 O2 Pyrite -209.83 -228.31 -18.48 FeS2 Siderite -8.77 -19.66 -10.89 FeCO3 Sulfur -93.19 -88.31 4.88 S Reading input data for simulation 3. SURFACE 1 Surface in equilibrium with brine equilibrate with solution 1 Surf 0.14 600 30 ------------------------------------------------------ Beginning of initial surface-composition calculations. Surface 1. Surface in equilibrium with brine Surf 8.181e-002 Surface charge, eq 4.386e-001 sigma, C/m**2 5.857e-002 psi, V -2.280e+000 -F*psi/RT 1.023e-001 exp(-F*psi/RT) 6.000e+002 specific area, m**2/g 1.800e+004 m**2 for 3.000e+001 g 1.400e-001 moles Mole Log Species Moles Fraction Molality Molality SurfOH2+ 9.998e-002 0.714 1.176e+000 0.071 SurfOH 3.267e-002 0.233 3.844e-001 -0.415 SurfOHAsO4-3 5.485e-003 0.039 6.454e-002 -1.190 SurfHAsO4- 1.474e-003 0.011 1.734e-002 -1.761 SurfO- 2.445e-004 0.002 2.877e-003 -2.541 SurfH2AsO4 1.460e-004 0.001 1.717e-003 -2.765 Reading input data for simulation 4. EXCHANGE 1 X 0.4 ------------------------------------------------------- Beginning of initial exchange-composition calculations. Exchange 1. X 4.000e-001 mol Equiv- Equivalent Log Species Moles alents Fraction Gamma NaX 3.415e-001 3.415e-001 8.536e-001 0.230 KX 3.730e-002 3.730e-002 9.324e-002 -0.228 CaX2 8.699e-003 1.740e-002 4.349e-002 0.159 MgX2 1.928e-003 3.856e-003 9.641e-003 0.483 FeX2 2.653e-013 5.307e-013 1.327e-012 -0.869 Reading input data for simulation 5. ----------- End of run.

Exercise: Make a Carbonate Ground Water Append to same file END Start with pure water (solution 2) Equilibrate with calcite and dolomite PCO2 = -1.5 Save result as solution 2 # gw.pqi SOLUTION_MASTER_SPECIES As H3AsO4 -1.0 74.9216 74.9216 SOLUTION_SPECIES #H3AsO4 primary master species H3AsO4 = H3AsO4 log_k 0.0 #H2AsO4- H3AsO4 = H2AsO4- + H+ log_k -2.243 delta_h -1.69 kcal #HAsO4-2 H3AsO4 = HAsO4-2 + 2H+ log_k -9.001 delta_h -0.92 kcal #AsO4-3 H3AsO4 = AsO4-3 + 3H+ log_k -20.597 delta_h 3.43 kcal SURFACE_MASTER_SPECIES Surf SurfOH SURFACE_SPECIES SurfOH = SurfOH log_k 0.0 SurfOH + H+ = SurfOH2+ log_k 7.29 SurfOH = SurfO- + H+ log_k -8.93 SurfOH + AsO4-3 + 3H+ = SurfH2AsO4 + H2O log_k 29.31 SurfOH + AsO4-3 + 2H+ = SurfHAsO4- + H2O log_k 23.51 SurfOH + AsO4-3 = SurfOHAsO4-3 log_k 10.58 SOLUTION 1 Seawater temp 25 pH 8.22 pe 8.45 redox pe units ppm density 1 Ca 412.3 Mg 1291.8 Na 10768 K 399.1 Fe .002 Alkalinity 141.682 as HCO3 Cl 19353 S(6) 2712 As .03 ppb -water 1 # kg END USE solution 1 EQUILIBRIUM_PHASES Halite 0 H2O Dolomite 0 0 Calcite 0 10 Gypsum 0 0 Anhydrite 0 0 CO2(g) -1.5 SAVE solution 1 SURFACE 1 Surface in equilibrium with brine -equilibrate with solution 1 Surf 0.14 600 30 EXCHANGE 1 X 0.4 SOLUTION 2 Pure water EQUILIBRIUM_PHASES 2 Calcite 0 10 Dolomite 0 10 CO2(g) -1.5 10 SAVE solution 2

Comprehensive Exam We want to simulate the reactions of carbonate ground water with the aquifer sediments Assume the aquifer initially contains a surface and exchanger that have been equilibrated with the brine as well as calcite and dolomite Simulate a volume of aquifer that sequentially receives 4 volumes of carbonate ground water What pH and arsenic concentrations do you find in each volume of pore water? # reaction.pqi SOLUTION_MASTER_SPECIES As H3AsO4 -1.0 74.9216 74.9216 SOLUTION_SPECIES #H3AsO4 primary master species H3AsO4 = H3AsO4 log_k 0.0 #H2AsO4- H3AsO4 = H2AsO4- + H+ log_k -2.243 delta_h -1.69 kcal #HAsO4-2 H3AsO4 = HAsO4-2 + 2H+ log_k -9.001 delta_h -0.92 kcal #AsO4-3 H3AsO4 = AsO4-3 + 3H+ log_k -20.597 delta_h 3.43 kcal SURFACE_MASTER_SPECIES Surf SurfOH SURFACE_SPECIES SurfOH = SurfOH log_k 0.0 SurfOH + H+ = SurfOH2+ log_k 7.29 SurfOH = SurfO- + H+ log_k -8.93 SurfOH + AsO4-3 + 3H+ = SurfH2AsO4 + H2O log_k 29.31 SurfOH + AsO4-3 + 2H+ = SurfHAsO4- + H2O log_k 23.51 SurfOH + AsO4-3 = SurfOHAsO4-3 log_k 10.58 SOLUTION 1 Seawater temp 25 pH 8.22 pe 8.45 redox pe units ppm density 1 Ca 412.3 Mg 1291.8 Na 10768 K 399.1 Fe .002 Alkalinity 141.682 as HCO3 Cl 19353 S(6) 2712 As .03 ppb -water 1 # kg END USE solution 1 EQUILIBRIUM_PHASES Halite 0 H2O Dolomite 0 0 Calcite 0 10 Gypsum 0 0 Anhydrite 0 0 CO2(g) -1.5 SAVE solution 1 SURFACE 1 Surface in equilibrium with brine -equilibrate with solution 1 Surf 0.14 600 30 EXCHANGE 1 X 0.4 SOLUTION 2 Pure water EQUILIBRIUM_PHASES 2 Calcite 0 10 Dolomite 0 10 CO2(g) -1.5 10 SAVE solution 2 EQUILIBRIUM_PHASES 1 Calcite Dolomite USER_PUNCH # Prints concentrations in mg/kgw to reaction.sel SELECTED_OUTPUT -file reaction.sel -reset false -ph true -headings Ca Mg Na Cl TDIC SO4 As -start 10 PUNCH TOT("Ca")*1000*40.08 20 PUNCH TOT("Mg")*1000*24.3 30 PUNCH TOT("Na")*1000*23 40 PUNCH TOT("Cl")*1000*35.5 50 PUNCH TOT("C(4)")*1000*61 60 PUNCH TOT("S(6)")*1000*96 70 PUNCH TOT("As")*1000*1000*74.3 -end USE solution 2 USE equilibrium_phases 1 USE surface 1 USE exchange 1 SAVE equilibrium_phases 1 SAVE surface 1 SAVE exchange 1

Chemical Reactions Ca, Mg exchanged for Na Calcite, dolomite dissolve pH increases Arsenic is released from surface sites Input file: H:\ntc\dk\phreeqc\reaction.pqi Output file: H:\ntc\dk\phreeqc\reaction.pqo Database file: C:\Program Files\USGS\Phreeqc Interactive 2.12.3\phreeqc.dat ------------------ Reading data base. SOLUTION_MASTER_SPECIES SOLUTION_SPECIES PHASES EXCHANGE_MASTER_SPECIES EXCHANGE_SPECIES SURFACE_MASTER_SPECIES SURFACE_SPECIES RATES END ------------------------------------ Reading input data for simulation 1. DATABASE C:\Program Files\USGS\Phreeqc Interactive 2.12.3\phreeqc.dat As H3AsO4 -1.0 74.9216 74.9216 H3AsO4 = H3AsO4 log_k 0.0 H3AsO4 = H2AsO4- + H+ log_k -2.243 delta_h -1.69 kcal H3AsO4 = HAsO4-2 + 2H+ log_k -9.001 delta_h -0.92 kcal H3AsO4 = AsO4-3 + 3H+ log_k -20.597 delta_h 3.43 kcal Surf SurfOH SurfOH = SurfOH log_k 0.0 SurfOH + H+ = SurfOH2+ log_k 7.29 SurfOH = SurfO- + H+ log_k -8.93 SurfOH + AsO4-3 + 3H+ = SurfH2AsO4 + H2O log_k 29.31 SurfOH + AsO4-3 + 2H+ = SurfHAsO4- + H2O log_k 23.51 SurfOH + AsO4-3 = SurfOHAsO4-3 log_k 10.58 SOLUTION 1 Seawater temp 25 pH 8.22 pe 8.45 redox pe units ppm density 1 Ca 412.3 Mg 1291.8 Na 10768 K 399.1 Fe .002 Alkalinity 141.682 as HCO3 Cl 19353 S(6) 2712 As .03 ppb water 1 # kg ------------------------------------------- Beginning of initial solution calculations. Initial solution 1. Seawater -----------------------------Solution composition------------------------------ Elements Molality Moles Alkalinity 2.406e-003 2.406e-003 As 4.150e-010 4.150e-010 Ca 1.066e-002 1.066e-002 Cl 5.657e-001 5.657e-001 Fe 3.711e-008 3.711e-008 K 1.058e-002 1.058e-002 Mg 5.507e-002 5.507e-002 Na 4.854e-001 4.854e-001 S(6) 2.926e-002 2.926e-002 ----------------------------Description of solution---------------------------- pH = 8.220 pe = 8.450 Activity of water = 0.981 Ionic strength = 6.748e-001 Mass of water (kg) = 1.000e+000 Total carbon (mol/kg) = 2.182e-003 Total CO2 (mol/kg) = 2.182e-003 Temperature (deg C) = 25.000 Electrical balance (eq) = 7.967e-004 Percent error, 100*(Cat-|An|)/(Cat+|An|) = 0.07 Iterations = 7 Total H = 1.110144e+002 Total O = 5.562980e+001 ----------------------------Distribution of species---------------------------- Log Log Log Species Molality Activity Molality Activity Gamma OH- 2.674e-006 1.629e-006 -5.573 -5.788 -0.215 H+ 7.981e-009 6.026e-009 -8.098 -8.220 -0.122 H2O 5.551e+001 9.806e-001 1.744 -0.009 0.000 As 4.150e-010 HAsO4-2 4.084e-010 1.273e-010 -9.389 -9.895 -0.506 H2AsO4- 5.879e-012 4.392e-012 -11.231 -11.357 -0.127 AsO4-3 7.378e-013 5.354e-014 -12.132 -13.271 -1.139 H3AsO4 3.965e-018 4.631e-018 -17.402 -17.334 0.067 C(4) 2.182e-003 HCO3- 1.516e-003 1.024e-003 -2.819 -2.990 -0.170 MgHCO3+ 2.198e-004 1.642e-004 -3.658 -3.785 -0.127 NaHCO3 1.669e-004 1.950e-004 -3.777 -3.710 0.067 MgCO3 8.924e-005 1.042e-004 -4.049 -3.982 0.067 NaCO3- 6.726e-005 5.026e-005 -4.172 -4.299 -0.127 CaHCO3+ 4.603e-005 3.110e-005 -4.337 -4.507 -0.170 CO3-2 3.826e-005 7.969e-006 -4.417 -5.099 -0.681 CaCO3 2.728e-005 3.187e-005 -4.564 -4.497 0.067 CO2 1.211e-005 1.415e-005 -4.917 -4.849 0.067 FeCO3 1.700e-016 1.985e-016 -15.770 -15.702 0.067 FeHCO3+ 1.423e-016 1.063e-016 -15.847 -15.973 -0.127 Ca 1.066e-002 Ca+2 9.504e-003 2.380e-003 -2.022 -2.623 -0.601 CaSO4 1.083e-003 1.265e-003 -2.965 -2.898 0.067 CaOH+ 8.604e-008 6.429e-008 -7.065 -7.192 -0.127 CaHSO4+ 5.979e-011 4.467e-011 -10.223 -10.350 -0.127 Cl 5.657e-001 Cl- 5.657e-001 3.528e-001 -0.247 -0.452 -0.205 FeCl+ 6.769e-016 5.058e-016 -15.169 -15.296 -0.127 FeCl+2 9.556e-019 2.978e-019 -18.020 -18.526 -0.506 FeCl2+ 6.281e-019 4.693e-019 -18.202 -18.329 -0.127 FeCl3 1.417e-020 1.656e-020 -19.849 -19.781 0.067 Fe(2) 6.007e-015 Fe+2 4.525e-015 1.039e-015 -14.344 -14.984 -0.639 FeSO4 4.213e-016 4.921e-016 -15.375 -15.308 0.067 FeOH+ 7.153e-017 5.345e-017 -16.145 -16.272 -0.127 FeHSO4+ 2.609e-023 1.949e-023 -22.584 -22.710 -0.127 Fe(3) 3.711e-008 Fe(OH)3 2.840e-008 3.318e-008 -7.547 -7.479 0.067 Fe(OH)4- 6.591e-009 4.924e-009 -8.181 -8.308 -0.127 Fe(OH)2+ 2.118e-009 1.583e-009 -8.674 -8.801 -0.127 FeOH+2 9.425e-014 2.937e-014 -13.026 -13.532 -0.506 FeSO4+ 1.093e-018 8.167e-019 -17.961 -18.088 -0.127 Fe+3 3.509e-019 2.795e-020 -18.455 -19.554 -1.099 Fe(SO4)2- 6.371e-020 4.761e-020 -19.196 -19.322 -0.127 Fe2(OH)2+4 2.462e-024 2.322e-026 -23.609 -25.634 -2.025 FeHSO4+2 4.228e-026 1.318e-026 -25.374 -25.880 -0.506 Fe3(OH)4+5 1.122e-029 7.678e-033 -28.950 -32.115 -3.165 H(0) 5.540e-037 H2 2.770e-037 3.236e-037 -36.557 -36.490 0.067 K 1.058e-002 K+ 1.041e-002 6.495e-003 -1.982 -2.187 -0.205 KSO4- 1.627e-004 1.216e-004 -3.789 -3.915 -0.127 KOH 3.137e-009 3.665e-009 -8.503 -8.436 0.067 Mg 5.507e-002 Mg+2 4.742e-002 1.371e-002 -1.324 -1.863 -0.539 MgSO4 7.330e-003 8.562e-003 -2.135 -2.067 0.067 MgOH+ 1.084e-005 8.100e-006 -4.965 -5.092 -0.127 Na 4.854e-001 Na+ 4.791e-001 3.387e-001 -0.320 -0.470 -0.151 NaSO4- 6.053e-003 4.523e-003 -2.218 -2.345 -0.127 NaOH 3.117e-007 3.641e-007 -6.506 -6.439 0.067 O(0) 6.554e-020 O2 3.277e-020 3.828e-020 -19.485 -19.417 0.067 S(6) 2.926e-002 SO4-2 1.463e-002 2.664e-003 -1.835 -2.574 -0.740 HSO4- 2.089e-009 1.561e-009 -8.680 -8.807 -0.127 ------------------------------Saturation indices------------------------------- Phase SI log IAP log KT Anhydrite -0.84 -5.20 -4.36 CaSO4 Aragonite 0.61 -7.72 -8.34 CaCO3 Calcite 0.76 -7.72 -8.48 CaCO3 CO2(g) -3.38 -4.85 -1.47 CO2 Dolomite 2.41 -14.68 -17.09 CaMg(CO3)2 Fe(OH)3(a) 0.19 5.08 4.89 Fe(OH)3 Goethite 6.09 5.09 -1.00 FeOOH Gypsum -0.63 -5.21 -4.58 CaSO4:2H2O H2(g) -33.34 -36.49 -3.15 H2 H2O(g) -1.52 -0.01 1.51 H2O Halite -2.50 -0.92 1.58 NaCl Hematite 14.20 10.19 -4.01 Fe2O3 Jarosite-K -7.52 -16.73 -9.21 KFe3(SO4)2(OH)6 Melanterite -15.41 -17.62 -2.21 FeSO4:7H2O O2(g) -16.52 -19.42 -2.89 O2 Siderite -9.19 -20.08 -10.89 FeCO3 End of simulation. Reading input data for simulation 2. USE solution 1 EQUILIBRIUM_PHASES Halite 0 H2O Dolomite 0 0 Calcite 0 10 Gypsum 0 0 Anhydrite 0 0 CO2(g) -1.5 SAVE solution 1 ----------------------------------------- Beginning of batch-reaction calculations. Reaction step 1. Using solution 1. Seawater Using pure phase assemblage 1. -------------------------------Phase assemblage-------------------------------- Moles in assemblage Phase SI log IAP log KT Initial Final Delta Anhydrite -0.00 -4.37 -4.36 0.000e+000 0.000e+000 Calcite 0.00 -8.48 -8.48 1.000e+001 9.910e+000-9.037e-002 CO2(g) -1.50 -19.65 -18.15 1.000e+001 1.000e+001 8.232e-004 Dolomite -0.00 -17.09 -17.09 0.000e+000 4.572e-002 4.572e-002 Gypsum 0.00 -4.58 -4.58 0.000e+000 2.875e-002 2.875e-002 Halite 0.00 1.58 1.58 H2O is reactant 1.000e+001 6.073e+001 5.073e+001 As 4.883e-009 4.150e-010 C 3.461e-003 2.942e-004 Ca 3.125e-001 2.656e-002 Cl 6.657e+000 5.657e-001 Fe 4.367e-007 3.711e-008 K 1.245e-001 1.058e-002 Mg 1.100e-001 9.350e-003 Na 5.712e+000 4.854e-001 S 5.972e-003 5.075e-004 pH = 5.814 Charge balance pe = 13.135 Adjusted to redox equilibrium Activity of water = 0.780 Ionic strength = 7.085e+000 Mass of water (kg) = 8.499e-002 Total alkalinity (eq/kg) = 3.251e-003 Total CO2 (mol/kg) = 3.461e-003 Iterations = 19 Total H = 9.434897e+000 Total O = 4.720205e+000 H+ 2.182e-006 1.534e-006 -5.661 -5.814 -0.153 OH- 1.099e-008 5.092e-009 -7.959 -8.293 -0.334 H2O 5.551e+001 7.804e-001 1.744 -0.108 0.000 As 4.883e-009 H2AsO4- 4.877e-009 2.515e-008 -8.312 -7.599 0.712 HAsO4-2 4.048e-012 2.862e-009 -11.393 -8.543 2.849 H3AsO4 1.321e-012 6.752e-012 -11.879 -11.171 0.709 AsO4-3 1.835e-021 4.728e-015 -20.736 -14.325 6.411 C(-4) 0.000e+000 CH4 0.000e+000 0.000e+000 -130.660 -129.952 0.709 C(4) 3.461e-003 CaHCO3+ 2.387e-003 1.383e-003 -2.622 -2.859 -0.237 HCO3- 4.204e-004 2.436e-004 -3.376 -3.613 -0.237 NaHCO3 2.598e-004 1.328e-003 -3.585 -2.877 0.709 CO2 2.106e-004 1.077e-003 -3.676 -2.968 0.709 MgHCO3+ 1.822e-004 9.393e-004 -3.740 -3.027 0.712 CaCO3 1.089e-006 5.565e-006 -5.963 -5.255 0.709 MgCO3 4.581e-007 2.341e-006 -6.339 -5.631 0.709 NaCO3- 2.606e-007 1.344e-006 -6.584 -5.872 0.712 CO3-2 6.607e-008 7.444e-009 -7.180 -8.128 -0.948 FeHCO3+ 1.378e-014 7.106e-014 -13.861 -13.148 0.712 FeCO3 1.019e-016 5.210e-016 -15.992 -15.283 0.709 Ca 3.125e-001 Ca+2 3.085e-001 4.450e-001 -0.511 -0.352 0.159 CaSO4 1.682e-003 8.599e-003 -2.774 -2.066 0.709 CaHSO4+ 1.499e-008 7.729e-008 -7.824 -7.112 0.712 CaOH+ 7.285e-009 3.756e-008 -8.138 -7.425 0.712 Cl 6.657e+000 Cl- 6.657e+000 3.940e+000 0.823 0.596 -0.228 FeCl2+ 1.543e-009 7.955e-009 -8.812 -8.099 0.712 FeCl3 6.132e-010 3.134e-009 -9.212 -8.504 0.709 FeCl+ 3.077e-012 1.587e-011 -11.512 -10.799 0.712 FeCl+2 6.395e-013 4.520e-010 -12.194 -9.345 2.849 Fe(2) 2.466e-011 Fe+2 2.156e-011 2.918e-012 -10.666 -11.535 -0.869 FeSO4 9.831e-015 5.025e-014 -14.007 -13.299 0.709 FeOH+ 9.101e-017 4.693e-016 -16.041 -15.329 0.712 FeHSO4+ 9.828e-020 5.068e-019 -19.008 -18.295 0.712 Fe(HS)2 0.000e+000 0.000e+000 -257.967 -257.258 0.709 Fe(HS)3- 0.000e+000 0.000e+000 -383.270 -382.558 0.712 Fe(3) 4.367e-007 Fe(OH)2+ 4.075e-007 2.101e-006 -6.390 -5.678 0.712 Fe(OH)3 2.693e-008 1.377e-007 -7.570 -6.861 0.709 Fe+3 9.035e-011 3.799e-012 -10.044 -11.420 -1.376 FeOH+2 1.765e-011 1.247e-008 -10.753 -7.904 2.849 Fe(OH)4- 1.238e-011 6.386e-011 -10.907 -10.195 0.712 FeSO4+ 7.823e-013 4.034e-012 -12.107 -11.394 0.712 Fe(SO4)2- 1.658e-015 8.547e-015 -14.781 -14.068 0.712 FeHSO4+2 2.345e-020 1.657e-017 -19.630 -16.781 2.849 Fe2(OH)2+4 1.678e-026 4.188e-015 -25.775 -14.378 11.397 Fe3(OH)4+5 2.859e-036 1.838e-018 -35.544 -17.736 17.808 H(0) 0.000e+000 H2 0.000e+000 0.000e+000 -41.756 -41.047 0.709 K 1.245e-001 K+ 1.245e-001 7.366e-002 -0.905 -1.133 -0.228 KSO4- 9.722e-006 5.013e-005 -5.012 -4.300 0.712 KOH 2.542e-011 1.299e-010 -10.595 -9.886 0.709 Mg 1.100e-001 Mg+2 1.084e-001 3.296e-001 -0.965 -0.482 0.483 MgSO4 1.464e-003 7.484e-003 -2.834 -2.126 0.709 MgOH+ 1.181e-007 6.087e-007 -6.928 -6.216 0.712 Na 5.712e+000 Na+ 5.710e+000 9.694e+000 0.757 0.986 0.230 NaSO4- 9.126e-004 4.705e-003 -3.040 -2.327 0.712 NaOH 6.373e-009 3.258e-008 -8.196 -7.487 0.709 O(0) 1.236e-011 O2 6.178e-012 3.158e-011 -11.209 -10.501 0.709 S(-2) 0.000e+000 H2S 0.000e+000 0.000e+000 -126.918 -126.209 0.709 HS- 0.000e+000 0.000e+000 -127.003 -127.337 -0.334 S-2 0.000e+000 0.000e+000 -133.431 -134.441 -1.010 S(6) 5.972e-003 SO4-2 1.903e-003 9.685e-005 -2.721 -4.014 -1.293 HSO4- 2.802e-009 1.445e-008 -8.553 -7.840 0.712 Anhydrite -0.00 -4.37 -4.36 CaSO4 Aragonite -0.14 -8.48 -8.34 CaCO3 Calcite 0.00 -8.48 -8.48 CaCO3 CH4(g) -127.09 -129.95 -2.86 CH4 CO2(g) -1.50 -2.97 -1.47 CO2 Dolomite -0.00 -17.09 -17.09 CaMg(CO3)2 Fe(OH)3(a) 0.81 5.70 4.89 Fe(OH)3 FeS(ppt) -129.14 -133.06 -3.92 FeS Goethite 6.81 5.81 -1.00 FeOOH Gypsum 0.00 -4.58 -4.58 CaSO4:2H2O H2(g) -37.90 -41.05 -3.15 H2 H2O(g) -1.62 -0.11 1.51 H2O H2S(g) -125.21 -126.21 -1.00 H2S Halite 0.00 1.58 1.58 NaCl Hematite 15.73 11.72 -4.01 Fe2O3 Jarosite-K 0.03 -9.18 -9.21 KFe3(SO4)2(OH)6 Mackinawite -128.41 -133.06 -4.65 FeS Melanterite -14.09 -16.30 -2.21 FeSO4:7H2O O2(g) -7.61 -10.50 -2.89 O2 Pyrite -209.83 -228.31 -18.48 FeS2 Siderite -8.77 -19.66 -10.89 FeCO3 Sulfur -93.19 -88.31 4.88 S Reading input data for simulation 3. SURFACE 1 Surface in equilibrium with brine equilibrate with solution 1 Surf 0.14 600 30 ------------------------------------------------------ Beginning of initial surface-composition calculations. Surface 1. Surface in equilibrium with brine Surf 8.181e-002 Surface charge, eq 4.386e-001 sigma, C/m**2 5.857e-002 psi, V -2.280e+000 -F*psi/RT 1.023e-001 exp(-F*psi/RT) 6.000e+002 specific area, m**2/g 1.800e+004 m**2 for 3.000e+001 g 1.400e-001 moles Mole Log Species Moles Fraction Molality Molality SurfOH2+ 9.998e-002 0.714 1.176e+000 0.071 SurfOH 3.267e-002 0.233 3.844e-001 -0.415 SurfOHAsO4-3 5.485e-003 0.039 6.454e-002 -1.190 SurfHAsO4- 1.474e-003 0.011 1.734e-002 -1.761 SurfO- 2.445e-004 0.002 2.877e-003 -2.541 SurfH2AsO4 1.460e-004 0.001 1.717e-003 -2.765 Reading input data for simulation 4. EXCHANGE 1 X 0.4 ------------------------------------------------------- Beginning of initial exchange-composition calculations. Exchange 1. X 4.000e-001 mol Equiv- Equivalent Log Species Moles alents Fraction Gamma NaX 3.415e-001 3.415e-001 8.536e-001 0.230 KX 3.730e-002 3.730e-002 9.324e-002 -0.228 CaX2 8.699e-003 1.740e-002 4.349e-002 0.159 MgX2 1.928e-003 3.856e-003 9.641e-003 0.483 FeX2 2.653e-013 5.307e-013 1.327e-012 -0.869 Reading input data for simulation 5. SOLUTION 2 Pure water EQUILIBRIUM_PHASES 2 Calcite 0 10 Dolomite 0 10 CO2(g) -1.5 10 SAVE solution 2 Initial solution 2. Pure water Pure water pH = 7.000 pe = 4.000 Activity of water = 1.000 Ionic strength = 1.001e-007 Total alkalinity (eq/kg) = 1.082e-010 Total carbon (mol/kg) = 0.000e+000 Total CO2 (mol/kg) = 0.000e+000 Electrical balance (eq) = -1.082e-010 Percent error, 100*(Cat-|An|)/(Cat+|An|) = -0.05 Iterations = 0 Total H = 1.110124e+002 Total O = 5.550622e+001 OH- 1.002e-007 1.001e-007 -6.999 -6.999 -0.000 H+ 1.001e-007 1.000e-007 -7.000 -7.000 -0.000 H2O 5.551e+001 1.000e+000 1.744 0.000 0.000 H(0) 1.416e-025 H2 7.079e-026 7.079e-026 -25.150 -25.150 0.000 O(0) 0.000e+000 O2 0.000e+000 0.000e+000 -42.080 -42.080 0.000 H2(g) -22.00 -25.15 -3.15 H2 H2O(g) -1.51 0.00 1.51 H2O O2(g) -39.19 -42.08 -2.89 O2 Using solution 2. Pure water Using pure phase assemblage 2. Calcite 0.00 -8.48 -8.48 1.000e+001 1.000e+001-4.733e-004 CO2(g) -1.50 -19.65 -18.15 1.000e+001 9.996e+000-4.131e-003 Dolomite 0.00 -17.09 -17.09 1.000e+001 9.999e+000-1.298e-003 C 7.200e-003 7.200e-003 Ca 1.771e-003 1.771e-003 Mg 1.298e-003 1.298e-003 pH = 7.054 Charge balance pe = -1.412 Adjusted to redox equilibrium Ionic strength = 8.894e-003 Mass of water (kg) = 9.999e-001 Total alkalinity (eq/kg) = 6.138e-003 Total CO2 (mol/kg) = 7.200e-003 Percent error, 100*(Cat-|An|)/(Cat+|An|) = -0.00 Iterations = 17 Total O = 5.552369e+001 OH- 1.254e-007 1.135e-007 -6.902 -6.945 -0.043 H+ 9.618e-008 8.821e-008 -7.017 -7.054 -0.038 H2O 5.551e+001 9.998e-001 1.744 -0.000 0.000 C(-4) 1.920e-024 CH4 1.920e-024 1.924e-024 -23.717 -23.716 0.001 C(4) 7.200e-003 HCO3- 5.967e-003 5.427e-003 -2.224 -2.265 -0.041 CO2 1.074e-003 1.077e-003 -2.969 -2.968 0.001 CaHCO3+ 8.740e-005 7.950e-005 -4.059 -4.100 -0.041 MgHCO3+ 5.956e-005 5.400e-005 -4.225 -4.268 -0.043 CaCO3 5.553e-006 5.565e-006 -5.255 -5.255 0.001 CO3-2 4.215e-006 2.885e-006 -5.375 -5.540 -0.165 MgCO3 2.337e-006 2.341e-006 -5.631 -5.631 0.001 Ca 1.771e-003 Ca+2 1.678e-003 1.148e-003 -2.775 -2.940 -0.165 CaOH+ 2.382e-009 2.159e-009 -8.623 -8.666 -0.043 H(0) 7.338e-015 H2 3.669e-015 3.676e-015 -14.435 -14.435 0.001 Mg 1.298e-003 Mg+2 1.236e-003 8.504e-004 -2.908 -3.070 -0.162 MgOH+ 3.860e-008 3.500e-008 -7.413 -7.456 -0.043 O2 0.000e+000 0.000e+000 -63.512 -63.511 0.001 CH4(g) -20.86 -23.72 -2.86 CH4 Dolomite 0.00 -17.09 -17.09 CaMg(CO3)2 H2(g) -11.28 -14.43 -3.15 H2 H2O(g) -1.51 -0.00 1.51 H2O O2(g) -60.62 -63.51 -2.89 O2 Reading input data for simulation 6. EQUILIBRIUM_PHASES 1 Calcite Dolomite Reading input data for simulation 7. USER_PUNCH SELECTED_OUTPUT file reaction.sel reset false ph true headings Ca Mg Na Cl TDIC SO4 As start 10 PUNCH TOT("Ca")*1000*40.08 20 PUNCH TOT("Mg")*1000*24.3 30 PUNCH TOT("Na")*1000*23 40 PUNCH TOT("Cl")*1000*35.5 50 PUNCH TOT("C(4)")*1000*61 60 PUNCH TOT("S(6)")*1000*96 70 PUNCH TOT("As")*1000*1000*74.3 end USE solution 2 USE equilibrium_phases 1 USE surface 1 USE exchange 1 SAVE equilibrium_phases 1 SAVE surface 1 SAVE exchange 1 Using solution 2. Solution after simulation 5. Using exchange 1. Exchange assemblage after simulation 4. Using surface 1. Surface assemblage after simulation 3. Calcite 0.00 -8.48 -8.48 1.000e+001 9.982e+000-1.823e-002 Dolomite 0.00 -17.09 -17.09 1.000e+001 9.982e+000-1.844e-002 ------------------------------Surface composition------------------------------ 9.764e-003 Surface charge, eq 5.234e-002 sigma, C/m**2 6.343e-002 psi, V -2.469e+000 -F*psi/RT 8.467e-002 exp(-F*psi/RT) SurfOH 9.134e-002 0.652 9.132e-002 -1.039 SurfOH2+ 3.629e-002 0.259 3.629e-002 -1.440 SurfOHAsO4-3 7.079e-003 0.051 7.078e-003 -2.150 SurfO- 5.266e-003 0.038 5.265e-003 -2.279 SurfHAsO4- 2.510e-005 0.000 2.509e-005 -4.600 SurfH2AsO4 3.227e-007 0.000 3.227e-007 -6.491 -----------------------------Exchange composition------------------------------ NaX 2.333e-001 2.333e-001 5.832e-001 -0.099 CaX2 4.566e-002 9.132e-002 2.283e-001 -0.381 KX 3.418e-002 3.418e-002 8.545e-002 -0.108 MgX2 2.062e-002 4.123e-002 1.031e-001 -0.366 FeX2 2.259e-013 4.518e-013 1.129e-012 -0.371 As 4.997e-010 4.998e-010 C 6.230e-002 6.232e-002 Ca 1.484e-003 1.484e-003 Fe 3.946e-014 3.946e-014 K 3.115e-003 3.116e-003 Mg 1.052e-003 1.053e-003 Na 1.082e-001 1.082e-001 pH = 6.619 Charge balance pe = -1.184 Adjusted to redox equilibrium Activity of water = 0.997 Ionic strength = 8.035e-002 Total alkalinity (eq/kg) = 4.432e-002 Total CO2 (mol/kg) = 6.230e-002 Electrical balance (eq) = 7.204e-002 Percent error, 100*(Cat-|An|)/(Cat+|An|) = 46.02 Iterations = 14 Total H = 1.110813e+002 Total O = 5.568744e+001 H+ 2.884e-007 2.407e-007 -6.540 -6.619 -0.079 OH- 5.329e-008 4.147e-008 -7.273 -7.382 -0.109 H2O 5.551e+001 9.970e-001 1.744 -0.001 0.000 As 4.997e-010 HAsO4-2 2.957e-010 1.175e-010 -9.529 -9.930 -0.401 H2AsO4- 2.040e-010 1.620e-010 -9.690 -9.791 -0.100 AsO4-3 9.871e-015 1.237e-015 -14.006 -14.907 -0.902 H3AsO4 6.697e-015 6.822e-015 -14.174 -14.166 0.008 C(-4) 1.500e-021 CH4 1.500e-021 1.528e-021 -20.824 -20.816 0.008 C(4) 6.230e-002 HCO3- 4.220e-002 3.383e-002 -1.375 -1.471 -0.096 CO2 1.802e-002 1.836e-002 -1.744 -1.736 0.008 NaHCO3 1.584e-003 1.613e-003 -2.800 -2.792 0.008 CaHCO3+ 2.706e-004 2.169e-004 -3.568 -3.664 -0.096 MgHCO3+ 1.856e-004 1.474e-004 -3.731 -3.832 -0.100 CO3-2 1.597e-005 6.591e-006 -4.797 -5.181 -0.384 NaCO3- 1.311e-005 1.041e-005 -4.882 -4.983 -0.100 CaCO3 5.463e-006 5.565e-006 -5.263 -5.255 0.008 MgCO3 2.299e-006 2.341e-006 -5.639 -5.631 0.008 FeHCO3+ 2.485e-014 1.973e-014 -13.605 -13.705 -0.100 FeCO3 9.053e-016 9.222e-016 -15.043 -15.035 0.008 Ca 1.484e-003 Ca+2 1.208e-003 5.026e-004 -2.918 -3.299 -0.381 CaOH+ 4.352e-010 3.455e-010 -9.361 -9.462 -0.100 Fe(2) 3.946e-014 Fe+2 1.369e-014 5.833e-015 -13.864 -14.234 -0.371 FeOH+ 9.623e-018 7.640e-018 -17.017 -17.117 -0.100 Fe(3) 2.389e-021 Fe(OH)2+ 1.683e-021 1.336e-021 -20.774 -20.874 -0.100 Fe(OH)3 7.000e-022 7.131e-022 -21.155 -21.147 0.008 Fe(OH)4- 3.393e-024 2.694e-024 -23.469 -23.570 -0.100 FeOH+2 2.452e-024 9.742e-025 -23.611 -24.011 -0.401 Fe+3 1.856e-028 3.642e-029 -27.732 -28.439 -0.707 Fe2(OH)2+4 0.000e+000 0.000e+000 -44.989 -46.593 -1.603 Fe3(OH)4+5 0.000e+000 0.000e+000 -62.642 -65.147 -2.505 H(0) 1.883e-014 H2 9.415e-015 9.591e-015 -14.026 -14.018 0.008 K 3.115e-003 K+ 3.115e-003 2.431e-003 -2.506 -2.614 -0.108 KOH 3.428e-011 3.492e-011 -10.465 -10.457 0.008 Mg 1.052e-003 Mg+2 8.645e-004 3.723e-004 -3.063 -3.429 -0.366 MgOH+ 7.053e-009 5.599e-009 -8.152 -8.252 -0.100 Na 1.082e-001 Na+ 1.066e-001 8.480e-002 -0.972 -1.072 -0.099 NaOH 2.278e-009 2.321e-009 -8.642 -8.634 0.008 O2 0.000e+000 0.000e+000 -64.354 -64.346 0.008 CH4(g) -17.96 -20.82 -2.86 CH4 CO2(g) -0.27 -1.74 -1.47 CO2 Fe(OH)3(a) -13.48 -8.59 4.89 Fe(OH)3 Goethite -7.59 -8.59 -1.00 FeOOH H2(g) -10.87 -14.02 -3.15 H2 Hematite -13.16 -17.17 -4.01 Fe2O3 O2(g) -61.45 -64.35 -2.89 O2 Siderite -8.53 -19.42 -10.89 FeCO3 Reading input data for simulation 8. Using exchange 1. Exchange assemblage after simulation 7. Using surface 1. Surface assemblage after simulation 7. Using pure phase assemblage 1. Pure-phase assemblage after simulation 7. Calcite 0.00 -8.48 -8.48 9.982e+000 9.978e+000-3.948e-003 Dolomite 0.00 -17.09 -17.09 9.982e+000 9.978e+000-3.387e-003 -2.130e-004 Surface charge, eq -1.142e-003 sigma, C/m**2 -3.320e-003 psi, V 1.292e-001 -F*psi/RT 1.138e+000 exp(-F*psi/RT) SurfOH 9.680e-002 0.691 9.681e-002 -1.014 SurfOH2+ 2.858e-002 0.204 2.859e-002 -1.544 SurfO- 7.510e-003 0.054 7.511e-003 -2.124 SurfOHAsO4-3 7.091e-003 0.051 7.091e-003 -2.149 SurfHAsO4- 1.385e-005 0.000 1.385e-005 -4.858 SurfH2AsO4 1.323e-007 0.000 1.324e-007 -6.878 NaX 2.070e-001 2.070e-001 5.174e-001 -0.062 CaX2 5.463e-002 1.093e-001 2.732e-001 -0.242 KX 3.334e-002 3.334e-002 8.335e-002 -0.065 MgX2 2.521e-002 5.042e-002 1.260e-001 -0.236 FeX2 2.231e-013 4.461e-013 1.115e-012 -0.236 As 2.798e-008 2.798e-008 C 1.792e-002 1.792e-002 Ca 1.294e-004 1.294e-004 Fe 2.825e-015 2.824e-015 K 8.385e-004 8.384e-004 Mg 9.224e-005 9.224e-005 Na 2.630e-002 2.630e-002 pH = 7.876 Charge balance pe = -2.519 Adjusted to redox equilibrium Activity of water = 0.999 Ionic strength = 2.262e-002 Total alkalinity (eq/kg) = 1.760e-002 Total CO2 (mol/kg) = 1.792e-002 Electrical balance (eq) = 9.977e-003 Percent error, 100*(Cat-|An|)/(Cat+|An|) = 22.33 Iterations = 12 Total H = 1.110224e+002 Total O = 5.555584e+001 OH- 8.737e-007 7.517e-007 -6.059 -6.124 -0.065 H+ 1.504e-008 1.331e-008 -7.823 -7.876 -0.053 H2O 5.551e+001 9.992e-001 1.744 -0.000 0.000 As 2.798e-008 HAsO4-2 2.666e-008 1.490e-008 -7.574 -7.827 -0.253 H2AsO4- 1.314e-009 1.136e-009 -8.881 -8.945 -0.063 AsO4-3 1.050e-011 2.839e-012 -10.979 -11.547 -0.568 H3AsO4 2.632e-015 2.645e-015 -14.580 -14.577 0.002 C(-4) 1.538e-022 CH4 1.538e-022 1.546e-022 -21.813 -21.811 0.002 C(4) 1.792e-002 HCO3- 1.714e-002 1.491e-002 -1.766 -1.826 -0.060 CO2 4.442e-004 4.466e-004 -3.352 -3.350 0.002 NaHCO3 1.886e-004 1.895e-004 -3.725 -3.722 0.002 CO3-2 9.173e-005 5.255e-005 -4.037 -4.279 -0.242 NaCO3- 2.558e-005 2.212e-005 -4.592 -4.655 -0.063 CaHCO3+ 1.379e-005 1.199e-005 -4.861 -4.921 -0.060 MgHCO3+ 9.422e-006 8.147e-006 -5.026 -5.089 -0.063 CaCO3 5.536e-006 5.565e-006 -5.257 -5.255 0.002 MgCO3 2.329e-006 2.341e-006 -5.633 -5.631 0.002 FeHCO3+ 1.030e-015 8.907e-016 -14.987 -15.050 -0.063 FeCO3 7.490e-016 7.529e-016 -15.126 -15.123 0.002 Ca 1.294e-004 Ca+2 1.100e-004 6.303e-005 -3.958 -4.200 -0.242 CaOH+ 9.083e-010 7.855e-010 -9.042 -9.105 -0.063 Fe(2) 2.825e-015 Fe+2 1.029e-015 5.972e-016 -14.987 -15.224 -0.236 FeOH+ 1.640e-017 1.418e-017 -16.785 -16.848 -0.063 Fe(3) 2.400e-020 Fe(OH)3 2.000e-020 2.011e-020 -19.699 -19.697 0.002 Fe(OH)2+ 2.404e-021 2.079e-021 -20.619 -20.682 -0.063 Fe(OH)4- 1.592e-021 1.377e-021 -20.798 -20.861 -0.063 FeOH+2 1.495e-025 8.361e-026 -24.825 -25.078 -0.253 Fe+3 5.176e-031 1.725e-031 -30.286 -30.763 -0.477 Fe2(OH)2+4 0.000e+000 0.000e+000 -47.715 -48.725 -1.010 Fe3(OH)4+5 0.000e+000 0.000e+000 -65.509 -67.088 -1.578 H(0) 2.728e-014 H2 1.364e-014 1.371e-014 -13.865 -13.863 0.002 K 8.385e-004 K+ 8.385e-004 7.220e-004 -3.077 -3.141 -0.065 KOH 1.870e-010 1.880e-010 -9.728 -9.726 0.002 Mg 9.224e-005 Mg+2 8.048e-005 4.669e-005 -4.094 -4.331 -0.236 MgOH+ 1.472e-008 1.273e-008 -7.832 -7.895 -0.063 Na 2.630e-002 Na+ 2.609e-002 2.260e-002 -1.584 -1.646 -0.062 NaOH 1.115e-008 1.121e-008 -7.953 -7.950 0.002 O2 0.000e+000 0.000e+000 -64.657 -64.655 0.002 CH4(g) -18.95 -21.81 -2.86 CH4 CO2(g) -1.88 -3.35 -1.47 CO2 Fe(OH)3(a) -12.03 -7.14 4.89 Fe(OH)3 Goethite -6.14 -7.14 -1.00 FeOOH H2(g) -10.71 -13.86 -3.15 H2 Hematite -10.26 -14.27 -4.01 Fe2O3 O2(g) -61.76 -64.65 -2.89 O2 Siderite -8.61 -19.50 -10.89 FeCO3 Reading input data for simulation 9. Using exchange 1. Exchange assemblage after simulation 8. Using surface 1. Surface assemblage after simulation 8. Using pure phase assemblage 1. Pure-phase assemblage after simulation 8. Calcite 0.00 -8.48 -8.48 9.978e+000 9.976e+000-1.721e-003 Dolomite 0.00 -17.09 -17.09 9.978e+000 9.977e+000-8.620e-004 -2.336e-003 Surface charge, eq -1.252e-002 sigma, C/m**2 -4.408e-002 psi, V 1.716e+000 -F*psi/RT 5.560e+000 exp(-F*psi/RT) SurfOH 9.776e-002 0.698 9.776e-002 -1.010 SurfOH2+ 2.705e-002 0.193 2.705e-002 -1.568 SurfO- 8.094e-003 0.058 8.095e-003 -2.092 SurfOHAsO4-3 7.092e-003 0.051 7.092e-003 -2.149 SurfHAsO4- 1.216e-005 0.000 1.216e-005 -4.915 SurfH2AsO4 1.089e-007 0.000 1.089e-007 -6.963 NaX 1.945e-001 1.945e-001 4.862e-001 -0.048 CaX2 5.895e-002 1.179e-001 2.947e-001 -0.188 KX 3.292e-002 3.292e-002 8.231e-002 -0.050 MgX2 2.734e-002 5.469e-002 1.367e-001 -0.185 FeX2 2.219e-013 4.438e-013 1.110e-012 -0.185 As 5.235e-007 5.235e-007 C 1.065e-002 1.064e-002 Ca 3.842e-005 3.841e-005 Fe 1.150e-015 1.150e-015 K 4.183e-004 4.182e-004 Mg 2.638e-005 2.638e-005 Na 1.248e-002 1.248e-002 pH = 8.593 Charge balance pe = -3.204 Adjusted to redox equilibrium Ionic strength = 1.216e-002 Total alkalinity (eq/kg) = 1.090e-002 Total CO2 (mol/kg) = 1.065e-002 Electrical balance (eq) = 2.123e-003 Percent error, 100*(Cat-|An|)/(Cat+|An|) = 8.96 Total H = 1.110146e+002 Total O = 5.553402e+001 OH- 4.398e-006 3.921e-006 -5.357 -5.407 -0.050 H+ 2.814e-009 2.552e-009 -8.551 -8.593 -0.042 H2O 5.551e+001 9.996e-001 1.744 -0.000 0.000 As 5.235e-007 HAsO4-2 5.172e-007 3.302e-007 -6.286 -6.481 -0.195 H2AsO4- 5.400e-009 4.827e-009 -8.268 -8.316 -0.049 AsO4-3 9.005e-010 3.280e-010 -9.046 -9.484 -0.439 H3AsO4 2.149e-015 2.155e-015 -14.668 -14.666 0.001 C(-4) 1.003e-023 CH4 1.003e-023 1.006e-023 -22.999 -22.997 0.001 C(4) 1.065e-002 HCO3- 1.022e-002 9.176e-003 -1.990 -2.037 -0.047 CO3-2 2.599e-004 1.686e-004 -3.585 -3.773 -0.188 NaHCO3 5.704e-005 5.720e-005 -4.244 -4.243 0.001 CO2 5.253e-005 5.267e-005 -4.280 -4.278 0.001 NaCO3- 3.894e-005 3.480e-005 -4.410 -4.458 -0.049 CaCO3 5.549e-006 5.565e-006 -5.256 -5.255 0.001 CaHCO3+ 2.563e-006 2.300e-006 -5.591 -5.638 -0.047 MgCO3 2.335e-006 2.341e-006 -5.632 -5.631 0.001 MgHCO3+ 1.748e-006 1.562e-006 -5.757 -5.806 -0.049 FeCO3 6.891e-016 6.910e-016 -15.162 -15.160 0.001 FeHCO3+ 1.754e-016 1.568e-016 -15.756 -15.805 -0.049 Ca 3.842e-005 Ca+2 3.030e-005 1.964e-005 -4.519 -4.707 -0.188 CaOH+ 1.429e-009 1.277e-009 -8.845 -8.894 -0.049 Fe(2) 1.149e-015 Fe+2 2.613e-016 1.708e-016 -15.583 -15.767 -0.185 FeOH+ 2.367e-017 2.116e-017 -16.626 -16.674 -0.049 Fe(3) 2.393e-019 Fe(OH)3 1.682e-019 1.687e-019 -18.774 -18.773 0.001 Fe(OH)4- 6.740e-020 6.025e-020 -19.171 -19.220 -0.049 Fe(OH)2+ 3.739e-021 3.342e-021 -20.427 -20.476 -0.049 FeOH+2 4.037e-026 2.577e-026 -25.394 -25.589 -0.195 Fe+3 2.452e-032 1.019e-032 -31.611 -31.992 -0.381 Fe2(OH)2+4 0.000e+000 0.000e+000 -48.968 -49.748 -0.780 Fe3(OH)4+5 0.000e+000 0.000e+000 -66.685 -67.904 -1.218 H(0) 2.357e-014 H2 1.179e-014 1.182e-014 -13.929 -13.927 0.001 K 4.183e-004 K+ 4.183e-004 3.731e-004 -3.379 -3.428 -0.050 KOH 5.053e-010 5.067e-010 -9.296 -9.295 0.001 Mg 2.638e-005 Mg+2 2.228e-005 1.455e-005 -4.652 -4.837 -0.185 MgOH+ 2.315e-008 2.069e-008 -7.635 -7.684 -0.049 Na 1.248e-002 Na+ 1.238e-002 1.108e-002 -1.907 -1.955 -0.048 NaOH 2.860e-008 2.868e-008 -7.544 -7.542 0.001 O2 0.000e+000 0.000e+000 -64.527 -64.526 0.001 CH4(g) -20.14 -23.00 -2.86 CH4 CO2(g) -2.81 -4.28 -1.47 CO2 Fe(OH)3(a) -11.10 -6.21 4.89 Fe(OH)3 Goethite -5.21 -6.21 -1.00 FeOOH H2(g) -10.78 -13.93 -3.15 H2 Hematite -8.42 -12.43 -4.01 Fe2O3 O2(g) -61.63 -64.53 -2.89 O2 Siderite -8.65 -19.54 -10.89 FeCO3 ------------------------------------- Reading input data for simulation 10. Using exchange 1. Exchange assemblage after simulation 9. Using surface 1. Surface assemblage after simulation 9. Using pure phase assemblage 1. Pure-phase assemblage after simulation 9. Calcite 0.00 -8.48 -8.48 9.976e+000 9.975e+000-1.327e-003 Dolomite -0.00 -17.09 -17.09 9.977e+000 9.977e+000-3.306e-004 -2.885e-003 Surface charge, eq -1.546e-002 sigma, C/m**2 -5.569e-002 psi, V 2.168e+000 -F*psi/RT 8.739e+000 exp(-F*psi/RT) SurfOH 9.799e-002 0.700 9.800e-002 -1.009 SurfOH2+ 2.665e-002 0.190 2.666e-002 -1.574 SurfO- 8.253e-003 0.059 8.254e-003 -2.083 SurfOHAsO4-3 7.091e-003 0.051 7.092e-003 -2.149 SurfHAsO4- 1.175e-005 0.000 1.175e-005 -4.930 SurfH2AsO4 1.034e-007 0.000 1.034e-007 -6.985 NaX 1.848e-001 1.848e-001 4.620e-001 -0.045 CaX2 6.235e-002 1.247e-001 3.117e-001 -0.174 KX 3.259e-002 3.259e-002 8.146e-002 -0.046 MgX2 2.895e-002 5.790e-002 1.448e-001 -0.171 FeX2 2.210e-013 4.419e-013 1.105e-012 -0.171 As 1.222e-006 1.222e-006 C 9.189e-003 9.188e-003 Ca 2.848e-005 2.848e-005 Fe 9.501e-016 9.500e-016 K 3.378e-004 3.378e-004 Mg 1.915e-005 1.915e-005 Na 9.682e-003 9.681e-003 pH = 8.797 Charge balance pe = -3.322 Adjusted to redox equilibrium Ionic strength = 1.013e-002 Total alkalinity (eq/kg) = 9.564e-003 Total CO2 (mol/kg) = 9.189e-003 Electrical balance (eq) = 5.492e-004 Percent error, 100*(Cat-|An|)/(Cat+|An|) = 2.82 Total H = 1.110130e+002 Total O = 5.552965e+001 OH- 6.969e-006 6.269e-006 -5.157 -5.203 -0.046 H+ 1.748e-009 1.596e-009 -8.757 -8.797 -0.040 H2O 5.551e+001 9.997e-001 1.744 -0.000 0.000 As 1.222e-006 HAsO4-2 1.211e-006 7.999e-007 -5.917 -6.097 -0.180 H2AsO4- 8.113e-009 7.314e-009 -8.091 -8.136 -0.045 AsO4-3 3.229e-009 1.270e-009 -8.491 -8.896 -0.405 H3AsO4 2.038e-015 2.043e-015 -14.691 -14.690 0.001 C(-4) 1.100e-024 CH4 1.100e-024 1.103e-024 -23.958 -23.957 0.001 C(4) 9.189e-003 HCO3- 8.724e-003 7.893e-003 -2.059 -2.103 -0.043 CO3-2 3.461e-004 2.319e-004 -3.461 -3.635 -0.174 NaCO3- 4.151e-005 3.742e-005 -4.382 -4.427 -0.045 NaHCO3 3.838e-005 3.846e-005 -4.416 -4.415 0.001 CO2 2.827e-005 2.833e-005 -4.549 -4.548 0.001 CaCO3 5.552e-006 5.565e-006 -5.256 -5.255 0.001 MgCO3 2.336e-006 2.341e-006 -5.632 -5.631 0.001 CaHCO3+ 1.590e-006 1.439e-006 -5.799 -5.842 -0.043 MgHCO3+ 1.084e-006 9.772e-007 -5.965 -6.010 -0.045 FeCO3 6.483e-016 6.499e-016 -15.188 -15.187 0.001 FeHCO3+ 1.023e-016 9.221e-017 -15.990 -16.035 -0.045 Ca 2.848e-005 Ca+2 2.134e-005 1.429e-005 -4.671 -4.845 -0.174 CaOH+ 1.647e-009 1.485e-009 -8.783 -8.828 -0.045 Fe(2) 9.495e-016 Fe+2 1.732e-016 1.168e-016 -15.761 -15.932 -0.171 FeOH+ 2.566e-017 2.314e-017 -16.591 -16.636 -0.045 Fe(3) 5.917e-019 Fe(OH)3 3.589e-019 3.597e-019 -18.445 -18.444 0.001 Fe(OH)4- 2.279e-019 2.055e-019 -18.642 -18.687 -0.045 Fe(OH)2+ 4.946e-021 4.459e-021 -20.306 -20.351 -0.045 FeOH+2 3.255e-026 2.150e-026 -25.487 -25.668 -0.180 Fe+3 1.206e-032 5.317e-033 -31.919 -32.274 -0.356 Fe2(OH)2+4 0.000e+000 0.000e+000 -49.185 -49.905 -0.720 Fe3(OH)4+5 0.000e+000 0.000e+000 -66.810 -67.936 -1.125 H(0) 1.585e-014 H2 7.923e-015 7.942e-015 -14.101 -14.100 0.001 K 3.378e-004 K+ 3.378e-004 3.040e-004 -3.471 -3.517 -0.046 KOH 6.586e-010 6.601e-010 -9.181 -9.180 0.001 Mg 1.915e-005 Mg+2 1.570e-005 1.058e-005 -4.804 -4.975 -0.171 MgOH+ 2.669e-008 2.406e-008 -7.574 -7.619 -0.045 Na 9.682e-003 Na+ 9.602e-003 8.666e-003 -2.018 -2.062 -0.045 NaOH 3.578e-008 3.586e-008 -7.446 -7.445 0.001 O2 0.000e+000 0.000e+000 -64.181 -64.180 0.001 CH4(g) -21.10 -23.96 -2.86 CH4 CO2(g) -3.08 -4.55 -1.47 CO2 Fe(OH)3(a) -10.78 -5.88 4.89 Fe(OH)3 Goethite -4.88 -5.88 -1.00 FeOOH H2(g) -10.95 -14.10 -3.15 H2 Hematite -7.76 -11.77 -4.01 Fe2O3 O2(g) -61.29 -64.18 -2.89 O2 Siderite -8.68 -19.57 -10.89 FeCO3 Reading input data for simulation 11. ----------- End of run.

Kinetic Reactions RATES Datablock—defines rates of reaction as function of solution composition KINETICS Datablock Select rate expression(s) Amount of reactant Stoichiometry of reaction Parameters

Monod Kinetics Rate Definition Cell Growth Parameter Value Vmax, 1/s 1e-5 KO2, mol/L X0, mol/L 0.4e-3

RATES Data Block See RATES in documentation for description of Basic statements Biomass -start 5 REM Biomass is the name applied to this rate expression 10 vmax = 1e-5 20 KO2 = 1e-5 25 REM KIN returns current amount for kinetic reactant 30 X = KIN("Biomass") 35 REM MOL returns molality of species 40 O2 = MOL("O2") 50 rate = vmax * X * O2/(KO2 + O2) 55 REM TIME is internally defined time step for integration 60 moles = rate*TIME 70 save -moles -end RATES Biomass -start 5 REM Biomass is the name applied to this rate expression 10 vmax = 1e-5 20 KO2 = 1e-5 25 REM KIN returns current amount for kinetic reactant 30 X = KIN("Biomass") 35 REM MOL returns molality of species 40 O2 = MOL("O2") 50 rate = vmax * X * O2/(KO2 + O2) 55 REM TIME is internally defined time step for integration 60 moles = rate*TIME 70 save -moles -end

KINETICS Data Block CH2O + O2 = CO2 + H2O Biomass -formula CH2O -1 Sub 1 -m 0.0004 # moles -steps 86400 in 4 steps # seconds -tol 1e-8

Sign Conventions SAVE in RATES Coefficient in KINETICS Kinetic reactant (KIN, M) Aqueous concentration + Decrease Increase -

Exercise Define a new element “Sub” with one species, Sub. Start with water in equilibrium with atmospheric O2, 1 mmol/kgw Sub. Define a Monod kinetics with the parameters from the previous slides Initial amount of biomass is 4e-4 moles The stoichiometry of the reaction replaces Sub with CH2O Run the simulation for 1 day printing results every ¼ day. # biomass.pqi #Cell growth kinetics SOLUTION_MASTER_SPECIES Sub Sub 0 1 1 SOLUTION_SPECIES Sub = Sub log_k 0 SOLUTION 1 pH 7 Sub 1 O(0) 1 O2(g) -0.7 RATES Biomass -start 5 REM Biomass is the name applied to this rate expression 10 vmax = 1e-6 20 KO2 = 1e-5 25 REM KIN returns current amount for kinetic reactant 30 X = KIN("Biomass") 35 REM MOL returns molality of species 40 O2 = MOL("O2") 50 rate = vmax * X * O2/(KO2 + O2) 55 REM TIME is internally defined time step for integration 60 moles = rate*TIME 70 save -moles -end KINETICS 1 -formula CH2O -1 Sub 1 -m 0.0004 -m0 0.0004 -tol 1e-008 -steps 86400 in 4 steps # seconds -step_divide 1 -runge_kutta 3 SELECTED_OUTPUT -file biomass.sel -reset false -time true -totals Sub O(0) C -kinetic_reactants Biomass

Kinetic Results Input file: H:\ntc\dk\phreeqc\biomass.pqi Output file: H:\ntc\dk\phreeqc\biomass.pqo Database file: C:\Program Files\USGS\Phreeqc Interactive 2.12.3\phreeqc.dat ------------------ Reading data base. SOLUTION_MASTER_SPECIES SOLUTION_SPECIES PHASES EXCHANGE_MASTER_SPECIES EXCHANGE_SPECIES SURFACE_MASTER_SPECIES SURFACE_SPECIES RATES END ------------------------------------ Reading input data for simulation 1. DATABASE C:\Program Files\USGS\Phreeqc Interactive 2.12.3\phreeqc.dat Sub Sub 0 1 1 Sub = Sub log_k 0 SOLUTION 1 pH 7 Sub 1 O(0) 1 O2(g) -0.7 Biomass start 5 REM Biomass is the name applied to this rate expression 10 vmax = 1e-6 20 KO2 = 1e-5 25 REM KIN returns current amount for kinetic reactant 30 X = KIN("Biomass") 35 REM MOL returns molality of species 40 O2 = MOL("O2") 50 rate = vmax * X * O2/(KO2 + O2) 55 REM TIME is internally defined time step for integration 60 moles = rate*TIME 70 save -moles end KINETICS 1 formula CH2O -1 Sub 1 m 0.0004 m0 0.0004 tol 1e-008 steps 86400 in 4 steps # seconds step_divide 1 runge_kutta 3 SELECTED_OUTPUT file biomass.sel reset false time true totals Sub O(0) C kinetic_reactants Biomass ------------------------------------------- Beginning of initial solution calculations. Initial solution 1. -----------------------------Solution composition------------------------------ Elements Molality Moles O(0) 5.113e-004 5.113e-004 Equilibrium with O2(g) Sub 1.000e-003 1.000e-003 ----------------------------Description of solution---------------------------- pH = 7.000 pe = 4.000 Activity of water = 1.000 Ionic strength = 1.001e-007 Mass of water (kg) = 1.000e+000 Total alkalinity (eq/kg) = 1.060e-010 Total carbon (mol/kg) = 0.000e+000 Total CO2 (mol/kg) = 0.000e+000 Temperature (deg C) = 25.000 Electrical balance (eq) = -1.060e-010 Percent error, 100*(Cat-|An|)/(Cat+|An|) = -0.05 Iterations = 4 Total H = 1.110124e+002 Total O = 5.550673e+001 ---------------------------------Redox couples--------------------------------- Redox couple pe Eh (volts) O(-2)/O(0) 13.6219 0.8058 ----------------------------Distribution of species---------------------------- Log Log Log Species Molality Activity Molality Activity Gamma OH- 1.001e-007 1.001e-007 -6.999 -7.000 -0.000 H+ 1.000e-007 1.000e-007 -7.000 -7.000 -0.000 H2O 5.551e+001 1.000e+000 1.744 -0.000 0.000 H(0) 1.416e-025 H2 7.079e-026 7.079e-026 -25.150 -25.150 0.000 O(0) 5.113e-004 O2 2.556e-004 2.556e-004 -3.592 -3.592 0.000 Sub 1.000e-003 Sub 1.000e-003 1.000e-003 -3.000 -3.000 0.000 ------------------------------Saturation indices------------------------------- Phase SI log IAP log KT H2(g) -22.00 -25.15 -3.15 H2 H2O(g) -1.51 -0.00 1.51 H2O O2(g) -0.70 -3.59 -2.89 O2 ----------------------------------------- Beginning of batch-reaction calculations. Reaction step 1. Using solution 1. Using kinetics 1. Kinetics defined in simulation 1. Kinetics 1. Kinetics defined in simulation 1. Time step: 21600 seconds Rate name Delta Moles Total Moles Reactant Coefficient Biomass 8.396e-006 4.084e-004 CH2O -1 Sub 1 C 8.396e-006 8.396e-006 Sub 9.916e-004 9.916e-004 pH = 5.763 Charge balance pe = 14.855 Adjusted to redox equilibrium Ionic strength = 1.729e-006 Total CO2 (mol/kg) = 8.396e-006 Percent error, 100*(Cat-|An|)/(Cat+|An|) = -0.00 Iterations = 55 Total H = 1.110125e+002 Total O = 5.550674e+001 H+ 1.728e-006 1.726e-006 -5.762 -5.763 -0.001 OH- 5.810e-009 5.801e-009 -8.236 -8.237 -0.001 C(-4) 0.000e+000 CH4 0.000e+000 0.000e+000 -145.732 -145.732 0.000 C(4) 8.396e-006 CO2 6.674e-006 6.674e-006 -5.176 -5.176 0.000 HCO3- 1.723e-006 1.720e-006 -5.764 -5.764 -0.001 CO3-2 4.703e-011 4.674e-011 -10.328 -10.330 -0.003 H(0) 0.000e+000 H2 0.000e+000 0.000e+000 -44.387 -44.387 0.000 O(0) 4.945e-004 O2 2.473e-004 2.473e-004 -3.607 -3.607 0.000 Sub 9.916e-004 Sub 9.916e-004 9.916e-004 -3.004 -3.004 0.000 CH4(g) -142.87 -145.73 -2.86 CH4 CO2(g) -3.71 -5.18 -1.47 CO2 H2(g) -41.24 -44.39 -3.15 H2 O2(g) -0.71 -3.61 -2.89 O2 Reaction step 2. Time step: 43200 seconds Biomass 1.696e-005 4.170e-004 CH2O -1 C 1.696e-005 1.696e-005 Sub 9.830e-004 9.830e-004 pH = 5.596 Charge balance pe = 15.018 Adjusted to redox equilibrium Ionic strength = 2.539e-006 Total CO2 (mol/kg) = 1.696e-005 Total O = 5.550675e+001 H+ 2.539e-006 2.535e-006 -5.595 -5.596 -0.001 OH- 3.957e-009 3.950e-009 -8.403 -8.403 -0.001 CH4 0.000e+000 0.000e+000 -145.366 -145.366 0.000 C(4) 1.696e-005 CO2 1.442e-005 1.442e-005 -4.841 -4.841 0.000 HCO3- 2.535e-006 2.531e-006 -5.596 -5.597 -0.001 CO3-2 4.717e-011 4.682e-011 -10.326 -10.330 -0.003 H2 0.000e+000 0.000e+000 -44.379 -44.379 0.000 O(0) 4.774e-004 O2 2.387e-004 2.387e-004 -3.622 -3.622 0.000 Sub 9.830e-004 Sub 9.830e-004 9.830e-004 -3.007 -3.007 0.000 CH4(g) -142.51 -145.37 -2.86 CH4 CO2(g) -3.37 -4.84 -1.47 CO2 H2(g) -41.23 -44.38 -3.15 H2 O2(g) -0.73 -3.62 -2.89 O2 Reaction step 3. Time step: 64800 seconds Biomass 2.569e-005 4.257e-004 CH2O -1 C 2.569e-005 2.569e-005 Sub 9.743e-004 9.743e-004 pH = 5.499 Charge balance pe = 15.111 Adjusted to redox equilibrium Ionic strength = 3.173e-006 Total CO2 (mol/kg) = 2.569e-005 H+ 3.173e-006 3.166e-006 -5.499 -5.499 -0.001 OH- 3.168e-009 3.162e-009 -8.499 -8.500 -0.001 CH4 0.000e+000 0.000e+000 -145.141 -145.141 0.000 C(4) 2.569e-005 CO2 2.252e-005 2.252e-005 -4.648 -4.648 0.000 HCO3- 3.170e-006 3.163e-006 -5.499 -5.500 -0.001 CO3-2 4.724e-011 4.685e-011 -10.326 -10.329 -0.004 H2 0.000e+000 0.000e+000 -44.371 -44.371 0.000 O(0) 4.599e-004 O2 2.300e-004 2.300e-004 -3.638 -3.638 0.000 Sub 9.743e-004 Sub 9.743e-004 9.743e-004 -3.011 -3.011 0.000 CH4(g) -142.28 -145.14 -2.86 CH4 CO2(g) -3.18 -4.65 -1.47 CO2 H2(g) -41.22 -44.37 -3.15 H2 O2(g) -0.75 -3.64 -2.89 O2 Reaction step 4. Time step: 86400 seconds Biomass 3.458e-005 4.346e-004 CH2O -1 C 3.458e-005 3.458e-005 Sub 9.654e-004 9.654e-004 pH = 5.431 Charge balance pe = 15.175 Adjusted to redox equilibrium Ionic strength = 3.715e-006 Total CO2 (mol/kg) = 3.458e-005 Total O = 5.550676e+001 H+ 3.715e-006 3.707e-006 -5.430 -5.431 -0.001 OH- 2.707e-009 2.701e-009 -8.568 -8.569 -0.001 CH4 0.000e+000 0.000e+000 -144.969 -144.969 0.000 C(4) 3.458e-005 CO2 3.087e-005 3.087e-005 -4.510 -4.510 0.000 HCO3- 3.712e-006 3.704e-006 -5.430 -5.431 -0.001 CO3-2 4.729e-011 4.686e-011 -10.325 -10.329 -0.004 H2 0.000e+000 0.000e+000 -44.362 -44.362 0.000 O(0) 4.421e-004 O2 2.211e-004 2.211e-004 -3.655 -3.655 0.000 Sub 9.654e-004 Sub 9.654e-004 9.654e-004 -3.015 -3.015 0.000 CH4(g) -142.11 -144.97 -2.86 CH4 CO2(g) -3.04 -4.51 -1.47 CO2 H2(g) -41.21 -44.36 -3.15 H2 O2(g) -0.76 -3.66 -2.89 O2 End of simulation. Reading input data for simulation 2. ----------- End of run.

PHREEQC Reactants Type and number are used to define PHAST reactions Keyword data blocks define reactants SOLUTION—Solutions EQUILIBRIUM_PHASES—Equilibrium minerals and gases EXCHANGE—Exchangers SURFACE—Surfaces KINETICS and RATES—Kinetic reactions SOLID_SOLUTIONS—Solid solutions GAS_PHASE—gas bubble (rarely used) Store reactants on shelves by type and number Put reactants together to define a reaction calculation SAVE/USE reactants Type and number are used to define PHAST reactions