Handbook of Solvents - George Wypych - ChemTech - Ventech!

1156 William R. Roy
Table 17.1.3. Henry�s Law constants (K H)
for the solvents at 25 o C
KH, atm-m 3 /mole Solvent (reference)
6.98
2.8
1.69
Decane (22)
F-114 (4)
Hexane (21)
0.53 F-113 (4)
9.74 x 10 -2
9.70 x 10 -2
3.04 x 10 -2
1.49 x 10 -2
1.03 x 10 -2
9.63 x 10 -3
8.4x10 -3
8.0x10 -3
7.0x10 -3
5.94 x 10 -3
5.43 x 10 -3
5.1x10 -3
3.58 x 10 -3
2.68 x 10 -3
1.4x10 -3
1.2x10 -3
7.48 x 10 -4
4x10 -4
1.35 x 10 -4
1.2x10 -4
9.4x10 -5
4.26 x 10 -5
2.44 x 10 -5
1.2x10 -5
1.05 x 10 -5
5.57 x 10 -6
1.2x10 -6
F-112 (4)
F-11 (4)
Carbon tetrachloride (4)
Tetrachloroethylene (4)
Trichloroethylene (4)
Tetrahydrofuran (4)
Ethylbenzene (17)
1,1,1-Trichloroethane (4)
Pyridine (4)
Toluene (4)
Benzene (4)
o-Xylene (4)
Chlorobenzene (23)
Dichloromethane (4)
Carbon disulfide (4)
o-Dichlorobenzene (4)
Diethyl ether (11)
Isobutyl alcohol (4)
Methanol (4)
Ethyl acetate (4)
Methyl isobutyl ketone (4)
Acetone (1)
Nitrobenzene (2)
Cyclohexanone (4)
Methyl ethyl ketone (4)
n-Butyl alcohol (4)
o-Cresol (4)
Table 17.1.4. Estimated half-lives for
the solvents in water at 20 o C
Half life, h Solvent
1.6 Tetrahydrofuran
2.6 Carbon disulfide
2.7 Hexane a
2.9 Toluene
3.0 Dichloromethane
3.1 Ethylbenzene
3.2 o-Xylene
3.4 Trichloroethylene, F-11
3.7 Carbon tetrachloride
4.0 F-112, F-113, F-114
4.2 Tetrachloroethylene
4.4 o-Dichlorobenzene
4.6 Chlorobenzene
5.3 Methanol
10 Ethyl acetate
18 Acetone
45 Nitrobenzene
74 Cyclohexanone
80 Isobutyl alcohol
90 Pyridine
a Based on a wind speed of 1 meter per second. 21
groundwater, the half-life values proposed
by Howard et al. 14 appear to be more variable
than those for surface water. For example,
the half-life of benzene ranges from 10
days in aerobic groundwater to 2 years in
anaerobic groundwater. 19 Such ranges in
half-lives make meaningful generalizations
difficult. However, it appears that methanol,
n-butyl alcohol, and other solvents (see
Figures 17.1.1 and 17.1.2) may biodegrade
in groundwater with a half-life that is less
than 60 days. As with surface water, the
chlorinated hydrocarbons may be relatively persistent in groundwater. Howard et al. 14 cautioned
that some of their proposed half-life generalizations were based on limited data or
from screening studies that were extrapolated to surface and groundwater. Scow 10 summarized
that it is currently not possible to predict rates of biodegradation because of a lack of
standardized experimental methods, and because the variables that control rates are not well
understood. Hence, Figures 17.1.1 and 17.1.2 should be viewed as a summary of the potential
for each solvent to degrade, pending more site-specific information.