CT = soil concentration (mg/kg)
Table 7. Theoretical mean con-
Θ = soil water content by volume (dimen-
version coefficients (CO) be-
tween soil vapor concentration
sionless)
(mg/L) and soil matrix concen-
n = soil porosity (dimensionless)
ρb = soil density (g/cm3)
tration (mg/kg) for common
VOCs (Rong 1996).
foc = soil organic carbon content (dimen-
CO
sionless)
Compound
(kg/L)
KH = Henry's law constant (dimension-
less)
Vinyl chloride
8.3
Trans-1,2-dichloroethene
1.32
Koc = organic carbon partition coefficient
Benzene
1.09
(cm3/g).
Trichloroethene
1.16
Tetrachoroethene
0.855
By letting the conversion coefficient CO equal
Toluene
0.565
o,m,p - Xylene
0.485
CG/CT,
1,2-Dichlorobenzene
0.0485
CO = (ρb KH)/[Θ + (n Θ) KH + ρb foc Koc].
Note: Based on a median soil organic
carbon content of 0.14%.
Table 8. Experimental values for conversion coefficient,
the ratio of chamber vapor analyte concentration (mg/L)
to mean soil concentration (mg/kg).
CO (kg/L)
Expt.
Soil
TDCE
Ben
TCE
Tol
PCE
p-Xyl
1
CR-S
0.28
--
0.26
--
0.28
--
CR-D
1.6
--
1.2
--
1.2
--
Wis
1.8
--
0.95
--
0.75
--
2
CR-S
0.67
--
0.49
--
0.52
--
CR-D
2.0
--
1.5
--
1.3
--
Wis
1.5
--
1.0
--
0.88
--
3
CR-S
0.29
--
0.29
--
0.29
--
CR-D
1.3
--
1.2
--
1.3
--
Wis
1.4
--
0.86
--
0.72
--
4
CR-S
0.39
--
0.34
--
0.27
--
CR-D
1.3
--
1.4
--
1.3
--
Wis
1.5
--
1.0
--
0.82
--
5
CR-S
0.91
--
0.48
--
0.30
--
CR-D
1.9
--
1.5
--
1.1
--
Wis
2.8
--
1.4
--
0.85
--
6
CR-S
1.1
0.54
0.43
0.20
0.28
0.076
CR-D
1.9
1.2
1.3
0.86
1.2
0.48
Wis
2.7
1.6
1.2
0.70
0.82
0.30
7
CR-S
1.1
0.56
0.48
0.23
0.27
0.088
CR-D
1.9
1.2
1.5
0.85
1.0
0.44
Wis
2.3
1.4
1.3
0.70
0.76
0.31
8
CR-S
0.83
0.37
0.32
0.14
0.16
0.048
CR-D
1.8
1.0
1.3
0.72
0.93
0.29
Wis
2.1
1.0
1.0
0.51
0.59
0.20
Means, standard deviations, and relative standard deviations
(in parentheses)
CR-S
0.696
0.490
0.386
0.190
0.296
0.0707
0.343
0.104 0.094 0.046 0.100 0.0205
(49%)
(21%) (24%) (24%) (34%)
(29%)
CR-D
1.71
1.13
1.36
0.810
1.17
0.403
0.28
0.12
0.13
0.078 0.14
0.100
(16%)
(11%)
(9.6%) (9.6%) (12%)
(25%)
Wis
2.01
1.33
1.09
0.637
0.774
0.273
0.55
0.31
0.19
0.110 0.092
0.055
(27%)
(23%)
(17%)
(17%) (12%)
(20%)
8