Geology Reference
In-Depth Information
Table 11.5 Thermodynamic properties of groundwater.
Values in kJ/mol
H
0
fi
G
0
fi
b
0
chi
Substance
x
i
[-]
H
2
O
1.00E+00
-286.0
-237.3
0.79
HCO3
6.46E-05
-692.3
-587.1
-52.9
Ca
2+
3.95E-05
-543.1
-553.8
170.0
SO4
2
2.96E-05
-909.7
-745.0
-129.8
Mg
+2
2.13E-05
-467.1
-455.0
174.6
SiO
2
7.54E-06
-911.4
-857.1
1.1
Cl
6.98E-06
-167.2
-131.3
-69.2
Na
+
6.66E-06
-240.2
-262.0
74.6
Al
+3
2.05E-06
-531.6
-485.6
308.7
NO3
1.47E-06
-207.5
-111.4
-105.1
K
+
9.67E-07
-252.5
-283.4
83.2
Fe
2+
5.55E-07
-89.2
-78.9
297.9
SUM
1.00
Table 11.6 Summary of the thermodynamic properties of the hydrosphere. Values in kJ/mol,
except for the volume which is expressed in Mkm
3
x
i
H
0
fi
G
0
fi
b
chi
x
i
.H
0
fi
x
i
. G
0
fi
x
i
.b
chi
Reservoir
Vol.
Oceans
1370
9.73E-01 -284.9 -237.3 0.57 -2.77E+02 -2.31E+02 5.54E-01
Ice
Caps and
Glaciers
29
2.05E-02 -286.0 -237.2 0.79 -5.86E+00 -4.86E+00 1.62E-02
Groundwater 9.5
6.80E-03 -286.0 -237.4 0.79 -1.94E+00 -1.61E+00 5.38E-03
Lakes
0.125
1.00E-04 -286.0 -237.2 0.79
-2.86E-02
-2.37E-02
7.92E-05
Streams
and
Rivers
0.0017
1.00E-06 -286.0 -237.2 0.79
-2.86E-04
-2.37E-04
7.93E-07
SUM
1408.63
1
-284.9
-237.3
0.58
free energy and chemical exergy of the hydrosphere can be approximated to that of
seawater.
It should be noted in the hydrosphere's tables presented, that the specific chemi-
cal exergy of all anions is negative. As explained in the previous chapter, chemical
exergy expresses the minimum work required for chemically combining the refe-
rence substances dispersed in the reference environment to obtain the resource. If
the reference substances are more stable than the compound under analysis, then its
chemical exergy will be negative. In the R.E. used here, which is based on the partial
stability model of Szargut (1989), the authors have selected reference substances in
an attempt to avoid the possibility of negative chemical exergies. However, in light
of the hydrosphere's results, this hasn't been fully achieved and the equilibrium
equilibrium substances found in seawater should be analysed more carefully, so as
to find more appropriate liquid reference substances. A good starting point would
be the studies of Pinaev (2006a,b).
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