Table 1 Thermodynamic equilibria and constants used in the geochemical modeling of the porewater chemistry in the Seaplane Lagoon sediments

Al(OH)₃(gibbsite) + 3H⁺ → A1³⁺ + 3H₂O

7.76

38

AlOOH(boehmite) + 3H⁺ → A1³⁺ + 2H₂O

7.56

38

CaCO₃(calcite) → Ca²⁺ + CO₃^2-

-8.48

39

CaMg(CO₃)₂(dolomite) → Ca²⁺ + Mg²⁺ + 2CO₃^2-

-18.14

39

CaSO₄ · 2H₂O(gypsum) → Ca²⁺ + SO₄^2- + 2H₂O

-4.48

40

Cd²⁺ + H₂O → CdOH⁺ + H⁺

-10.08

41

Cd²⁺ + 2H₂O → Cd(OH)₂⁰ + 2H⁺

-20.34

41

Cd²⁺ + 3H₂O → Cd(OH)₃^-1 + 3H⁺

-33.29

41

Cd²⁺ + 4H₂O → Cd(OH)₄^2- + 4H⁺

-47.33

41

Cd²⁺ + Cl^- → CdCl⁺

1.97

42

Cd²⁺ + 2C1^- → CdCl₂(aq)

2.59

42

Cd²⁺ + 3C1^- → CdCl₃^-

2.34

42

Cd²⁺ + 4C1^- → CdCl₄^2-

-1.46

42

Cd²⁺ + CO₃^2- → CdCO₃⁰

3.00

43

Cd²⁺ + 2CO₃^2- → Cd(CO₃)₂^2-

6.40

43

Cd²⁺ + CO₃^2- + H⁺ → CdHCO₃⁺

11.83

43

Cd²⁺ + SO₄^2- → CdSO₄⁰

-0.003

44

CdHS⁺ → HS^- + Cd²⁺

-9.02

45^a

Cd(HS)₂ → 2HS^- + Cd²⁺

-16.53

45^a

Cd(OH)₂(beta) + 2H⁺ → Cd²⁺ + 2H₂O

13.64

41

CdS + H⁺ → HS^- + Cd²⁺

-15.91

44

CdSO₄(anglesite) → Cd²⁺ + SO₄^2-

-0.11

44

CdCO₃(otavite)→ Cd²⁺ + CO₃^2-

-12.1

43

CdO(monteponite) + 2H⁺ → Cd²⁺ + H₂O

15.1

46

Cr³⁺ + Cl^- → CrCl²⁺

7.60

47

Cr³⁺ + 2C1^- → CrCl₂^-

7.91

47

CrHS²⁺ → HS^- + Cr³⁺

-9.88

45^a

CrS + 2H⁺ + 0.25O₂(aq) → 0.5H₂O + Cr³⁺ + HS^-

31.35

47

Cr₂O₃(eskolaite) + 6H⁺ → 3H₂O + 2Cr³⁺

7.64

44

Cu²⁺ + Cl^- → CuCl⁺

0.40

42

Cu²⁺ + 2C1^- → CuCl₂(aq)

-0.69

42

Cu²⁺ + 3C1^- → CuCl₃^-

-2.29

42

Cu²⁺ + 4C1^- → CuCl₄^2-

-4.94

42

CuS(covellite) + H⁺ → HS^- + Cu²⁺

-22.83

39

CuFeS₂(chalcopyrite) + 2H⁺ → 2HS^- + Fe²⁺ + Cu²⁺

-32.56

39

Cu₂CO₃(OH)₂(malachite) + 2H⁺ → 2H₂O + CO₃^2- + 2Cu²⁺

-4.40

39

CuO(tenorite) + 2H⁺ → Cu²⁺ + H₂O

7.66

39

FeHS⁺ → HS^- + Fe²⁺

-5.52

48^a

(Fe)₂HS³⁺ → HS^- + 2Fe²⁺

-10.02

48^a

(Fe)₃HS⁵⁺ → HS^- + 3Fe²⁺

-15.30

48^a

Fe²⁺ + Cl^- → FeCl⁺

-0.16

42

Fe²⁺ + 2C1^- → FeCl₂(aq)

-8.17

42

Fe³⁺ + Cl^- → FeCl²⁺

1.47

42

Fe³⁺ + 2C1^- → FeCl₂⁺

2.13

49

Fe³⁺ + 4C1^- → FeCL₄^-

-0.79

49

FeS₂(pyrite) + H₂O → Fe²⁺ + 2HS^2- + 0.5O₂(aq)

-59.23

39

FeS(pyrrhotite) + H⁺ → HS^- + Fe²⁺

-3.72

39

FeCO₃(siderite) → Fe²⁺ + CO₃^2-

-10.52

39

FeOOH(goethite) + 2H⁺ → Fe²⁺ + 1.5H₂O + 0.25O₂(aq)

-7.96

40

Na_0.33Fe₂Al_0.33Si_3.67O₁₀(OH)₂(Na-nontronite) + 5.32H⁺ → 2Fe²⁺ + 0.33A1³⁺ + O.5O₂(aq) + 0.33Na⁺ + 3.67SiO₂ + 3.66H₂O

-28.51

50

Mg₅Al₂Si₃O₁₀(OH)₈ (7 Å chlorite) + 16H⁺ → 2A1³⁺ + 12H₂O + 3SiO₂(aq) + 5 Mg²⁺

70.61

39

Mn²⁺ + Cl^- → MnCl⁺

-0.14

42

Mn²⁺ + 3C1^- → MnCl₃^-

-0.77

44

MnHS⁺ → HS^- + Mn²⁺

-5.00

48^a

(Mn)₂HS³⁺ → HS^-+2Mn²⁺

-9.55

48^a

(Mn)₃HS⁵⁺ → HS^- + 3Mn²⁺

-13.63

48^a

MnS(alabandite) + H⁺ → HS^-+Mn²⁺

-0.05

39

MnCO₃(rhodochrosite) → Mn²⁺ + CO₃^2-

-10.52

39

Ni(OH)₂ + 2H⁺ → Ni²⁺ + 2H₂O

7.64

44

Ni²⁺ + Cl^- → NiCl⁺

-1.00

42

NiCO₃ → CO₃^2- + Ni²⁺

-6.82

44

NiHS⁺ → HS^- + Ni²⁺

-5.29

48^a

(Ni)₂HS³⁺ → HS^- + 2Ni²⁺

-9.82

48^a

(Ni)₃HS⁵⁺ → HS^- + 3Ni²⁺

-13.65

48^a

NiS₂(vaesite) + H₂O → Ni²⁺ + 2HS^- + 0.5O₂(aq)

-61.34

39

NiS(millerite) + H⁺ → HS^- + Ni²⁺

-8.03

51

PbS(galena) + H⁺ → HS^- + Pb²⁺

-14.85

44

Pb²⁺ + H₂O → PbOH⁺ + H⁺

-7.7

52

Pb²⁺ + 2H₂O → Pb(OH)₂ + 2H⁺

-17.09

52

Pb²⁺ + 3H₂O → Pb(OH)₃^- + 3H⁺

-28.09

52

Pb²⁺ + Cl^- → Pb Cl⁺

1.44

42

Pb²⁺ + 2C1^- → PbCl₂(aq)

2.00

42

Pb²⁺ + 3C1^- → Pb C1₃^-

1.69

42

Pb²⁺ + 4C1- → Pb C1₄^2-

1.43

42

Pb²⁺ + CO₃^2- → PbCO₃

6.58

53

Pb²⁺ + 2CO₃^2- → Pb(CO₃)^2-

9.40

53

PbCO₃(cerussite) → Pb²⁺ + CO₃^2-

-13.54

20

Pb₃(CO₃)₂(OH)₂(hydrocerussite) + 2H⁺ → 2CO₃^2- + 3Pb²⁺ + 2H₂O

-18.81

52

PbSO₄(anglesite) → Pb²⁺ + SO₄^2-

-7.85

39

PbHS⁺ → HS^- + Pb²⁺

-8.62

45^a

Pb(HS)₂ → 2HS^- + Pb²⁺

-16.43

45^a

SiO₂(quartz) → SiO₂(aq)

-4.0

39

SiO₂(α-cristobalite) → SiO₂(aq)

-3.45

39

SiO₂(am. si.) → SiO₂(aq)

-2.71

39

Zn²⁺ + H₂O → ZnOH⁺ + H⁺

-8.96

54

Zn²⁺ + 2H₂O → Zn(OH)₂⁰ + 2H⁺

-28.04

44

Zn²⁺ + 3H₂O → Zn(OH)₃^- + 3H⁺

-28.83

44

Zn²⁺ + 4H₂O → Zn(OH)₄^- + 4H⁺

-41.61

44

Zn²⁺ + Cl^- → ZnCl⁺

1.99

42

Zn²⁺ + 2C1^- → ZnCl₂(aq)

2.51

42

Zn²⁺ + 3C1^- → ZnCl₃^-

-0.02

42

Zn²⁺ + CO₃^2- + H⁺ → ZnHCO₃⁺

8.91

54

Zn²⁺ + CO₃^2- → ZnCO₃⁰

3.9

55

Zn²⁺ + SO₄^2- → ZnSO₄⁰

-0.026

44

Zn₂S₃^2- + 3H⁺ → 3HS^- + 2Zn²⁺

-1.07

56^a

Zn₄S₆^4- + 6H⁺ → 6HS^- + 4Zn²⁺

-5.22

56^a

ZnS(sphalerite) + H⁺ → HS^- + Zn²⁺

-11.44

39

Zn(OH)₂(β) + 2H⁺ → Zn²⁺ + 2H₂O

11.93

44

Zn(OH)₂(ε) + 2H⁺ → Zn²⁺ + 2H₂O

11.66

44

Zn(OH)₂(γ) + 2H⁺ → Zn²⁺ + 2H₂O

11.88

44

ZnSO₄(solid) → Zn²⁺ + SO₄^2-

3.55

44

ZnCO₃(smithsonite) → Zn²⁺ + CO₃^2-

-9.87

20

Zn₅(OH)₆(CO₃)₂ (hydrozincite) + 6H⁺

9.65

57

→ 5Zn²⁺ + 2CO₃^2- + 6H₂O