def test_NaCl_H2CO3():
"""Can we solve NaCl + CO2 with the H2CO3 equilibria?"""
totals = pz.odict(Na=1.5, Cl=1.5, CO2=0.1)
ks_constants = {
"H2O": 10**-14,
"H2CO3": 10**-5,
"HCO3": 10**-9,
}
ptargets = eq.stoichiometric.solve(totals, ks_constants)
solutes = eq.components.get_solutes(totals, ks_constants, ptargets)
assert len(ptargets) == 1
assert len(solutes) == 7
assert np.isclose(
solutes["H"] + solutes["Na"],
solutes["OH"] + solutes["Cl"] + 2 * solutes["CO3"] + solutes["HCO3"],
**tol)
assert np.isclose(solutes["H"] * solutes["OH"], ks_constants["H2O"], **tol)
assert np.isclose(solutes["CO3"] * solutes["H"] / solutes["HCO3"],
ks_constants["HCO3"], **tol)
assert np.isclose(solutes["HCO3"] * solutes["H"] / solutes["CO2"],
ks_constants["H2CO3"], **tol)
assert np.isclose(solutes["Na"], totals["Na"], **tol)
assert np.isclose(solutes["Cl"], totals["Cl"], **tol)
assert np.isclose(solutes["CO2"] + solutes["HCO3"] + solutes["CO3"],
totals["CO2"], **tol)
def test_pure_water():
"""Can we solve pure water?"""
totals = pz.odict()
ks_constants = {"H2O": 10**-14}
ptargets = eq.stoichiometric.solve(totals, ks_constants)
solutes = eq.components.get_solutes(totals, ks_constants, ptargets)
assert len(ptargets) == 1
assert len(solutes) == 2
assert np.isclose(solutes["H"], solutes["OH"], **tol)
assert np.isclose(solutes["H"] * solutes["OH"], ks_constants["H2O"], **tol)
def test_NaCl():
"""Can we solve NaCl?"""
totals = pz.odict(Na=1.5, Cl=1.5)
ks_constants = {"H2O": 10**-14}
ptargets = eq.stoichiometric.solve(totals, ks_constants)
solutes = eq.components.get_solutes(totals, ks_constants, ptargets)
assert len(ptargets) == 1
assert len(solutes) == 4
assert np.isclose(solutes["H"], solutes["OH"], **tol)
assert np.isclose(solutes["H"] * solutes["OH"], ks_constants["H2O"], **tol)
assert np.isclose(solutes["Na"], totals["Na"], **tol)
assert np.isclose(solutes["Cl"], totals["Cl"], **tol)
def test_NaCl_SO4_only():
"""Can we solve NaCl + SO4 without the HSO4 equilibrium?"""
totals = pz.odict(Na=1.5, Cl=1.5, SO4=1.0)
ks_constants = {"H2O": 10**-14}
ptargets = eq.stoichiometric.solve(totals, ks_constants)
solutes = eq.components.get_solutes(totals, ks_constants, ptargets)
assert len(ptargets) == 1
assert len(solutes) == 5
assert np.isclose(solutes["H"] + solutes["Na"],
solutes["OH"] + solutes["Cl"] + 2 * solutes["SO4"],
**tol)
assert np.isclose(solutes["H"] * solutes["OH"], ks_constants["H2O"], **tol)
assert np.isclose(solutes["Na"], totals["Na"], **tol)
assert np.isclose(solutes["Cl"], totals["Cl"], **tol)
assert np.isclose(solutes["SO4"], totals["SO4"], **tol)
def test_get_constants():
"""Does the get_constants function agree with the full thermodynamic solver for
non-zero total molalities?
"""
totals = pz.odict(Na=4.0, Cl=4.0, CO2=0.1, PO4=0.5, F=1.0)
solutes, pks_constants = pz.solve(totals)
which_constants = ["H2CO3", "HCO3", "HF"]
f_ks_constants = eq.stoichiometric.get_constants(
solutes, which_constants=which_constants)
f_pks_constants = {k: -np.log10(v) for k, v in f_ks_constants.items()}
for c in which_constants:
assert np.isclose(pks_constants[c],
f_pks_constants[c],
rtol=0,
atol=1e-8)
def test_get_constants_zero():
"""Can we retrieve the carbonic acid and HF stoichiometric equilibrium constants
when the total dissolved inorganic carbon and fluoride are zero?
"""
# Solve without DIC and HF
totals = pz.odict(Na=1.5, Cl=3.5)
ks_constants = {"H2O": 10**-14}
ptargets = eq.stoichiometric.solve(totals, ks_constants)
solutes = eq.components.get_solutes(totals, ks_constants, ptargets)
# Get DIC and HF equilibria
which_constants = ["H2CO3", "HCO3", "HF"]
dic_eq = eq.stoichiometric.get_constants(solutes,
which_constants=which_constants)
assert len(dic_eq) == len(which_constants)
for c in which_constants:
assert c in dic_eq
assert isinstance(dic_eq[c].item(), float)
def test_all_ptargets():
"""Can we solve with all ptargets active?"""
totals = pz.odict(Ca=2.0, Cl=4.0, CO2=0.1, PO4=0.5, F=1.0)
ks_constants = {
"H2O": 10**-14,
"H2CO3": 10**-5,
"HCO3": 10**-9,
"HF": 10**-2,
"H3PO4": 10**-11,
"H2PO4": 10**-6,
"HPO4": 10**-3,
"CaCO3": 10**-4,
"CaF": 10**1,
"CaH2PO4": 10**-7,
}
ptargets = eq.stoichiometric.solve(totals, ks_constants)
solutes = eq.components.get_solutes(totals, ks_constants, ptargets)
assert len(ptargets) == 4
assert len(solutes) == 16
assert np.isclose(solutes["H"] * solutes["OH"], ks_constants["H2O"], **tol)
def get_activity_water(data_row):
dr = pz.odict(data_row[m_cols])
return np.round(pz.activity_water(dr, **params).item(), decimals=4)