Table 3 Aqueous complexes and their equilibrium constants at 25 °C (Primary species include: H2O, H+, Ca2+, Mg2+, Na+, K+, Fe2+, AlO2 −, SiO2 (aq), HCO3 −, SO4 2−, Cl−, O2 (aq), Pb2+, H3AsO4 (aq), UO2 2+).
From: Arsenic mobilization in shallow aquifers due to CO2 and brine intrusion from storage reservoirs
Species | LogK | Species | LogK | Species | LogK | Species | LogK |
|---|---|---|---|---|---|---|---|
OH− | 13.99 | CaCO3 (aq) | 7.01 | SO2 (aq) | 37.57 | HAsO4 2− | 9.01 |
CaCl+ | 0.70 | KCl (aq) | 1.50 | HSO3 − | 39.42 | AsO4 3− | 20.6 |
CaCl2 (aq) | 0.65 | MgCl+ | 0.14 | PbCl+ | −1.45 | HAsO2 (aq) | 23.54 |
CaSO4 (aq) | −2.10 | MgSO4 (aq) | −2.38 | PbCl2 (aq) | −2.01 | H3AsO3 (aq) | 23.61 |
NaCl (aq) | 0.78 | NaSO4 − | −0.81 | PbCl3 − | −1.70 | H2AsO3 − | 32.78 |
FeCl+ | 0.17 | KSO4 − | −0.88 | PbCl4 2− | −1.50 | UO2(CO3)3 4− | 9.15 |
FeHCO3 + | −2.04 | NaHSiO3 (aq) | 8.30 | PbOH+ | 7.57 | UO2(CO3)2 2− | 4.05 |
FeCO3 (aq) | 4.88 | CaOH+ | 12.85 | Pb(OH)2 (aq) | 17.07 | UO2(SO4)2 2− | −3.97 |
FeCl4 2− | 1.94 | NaOH (aq) | 14.15 | Pb(OH)3 − | 28.07 | UO2Cl+ | −0.15 |
NaHCO3 (aq) | −0.17 | NaCO3 − | 9.82 | Pb(CO3)2 2− | 11.24 | UO2SO4 (aq) | −3.06 |
CaHCO3 + | −1.04 | H3SiO4 − | 9.81 | PbO (aq) | 16.98 | UO2OH+ | 5.22 |
MgHCO3 + | −1.03 | Fe3+ | −8.49 | PbHCO3 + | −2.89 | UO2CO3 (aq) | 0.39 |
CO2 (aq) | −6.34 | CH4 (aq) | 144.15 | PbCO3 (aq) | 3.06 | ||
CO3 2− | 10.33 | H2 (aq) | 46.11 | H2AsO4 − | 2.25 |
