Geoscience Reference
In-Depth Information
Fig. 8.8
Major remaining components of kerosene during the volatilization process (Yaron et al.
1998
)
permeability; that is, their respective values were 0.0812 ± 0.009 and
0.145 ± 0.011 cm
2
. Figure
8.10
presents the volatilization of kerosene as affected
by the soil aggregation, when the initial amount applied was equivalent to the
retention capacity. The more permeable fraction releases kerosene faster and thus
enhances volatilization.
These examples indicate that aggregation and pore size distribution parameters
affect volatilization of petroleum products from a contaminated subsurface. Fine
and Yaron (
1993
) report that kerosene volatilization depends on the type of soil.
Tests on four soils with a clay content increasing from 0.3 to 74.4 %, and OM
content ranging from 0.01 to 5.1 % (Fig.
8.11
), showed significant variations in
rate and amount of volatilization over an 18-day period. This effect was attributed
not only to the soil composition but also to the soil porosity and aggregation status.
Changes in the chemical composition of residual kerosene, resulting from
volatilization of the light fractions, cause changes in the physical properties of the
remaining product. Table
8.3
shows the effect of the differential volatilization on
kerosene viscosity, surface tension, and density. When 20, 40, and 60 % of the
initial amount of kerosene was removed by the transfer of light fractions to the
atmosphere, the viscosity of the remaining kerosene was affected strongly. Neg-
ligible effects on liquid density and on surface tension were observed.
