Geoscience Reference
In-Depth Information
Fig. 18.46 Fourier transform
infrared (FTIR) spectra of
humic acids isolated from the
unamended soil (SO),
composted sewage sludge
(CS), and soils amended with
CS at 80 t/ha/yr for 1, 2, and
3 years 80-02, 80-03, and 80-
04, respectively (Fernandez
et al.
2009
). Reprinted from
Fernandez et al. (
2009
).
Copyright 2009 with
permission from Elsevier
The fate of kerosene—a widely used petroleum product containing about 100
hydrocarbon components—may be considered to illustrate the interaction between
petroleum products and the soil-subsurface system (see also
Sect. 8.2.3
). The
retention capacity and physical attenuation of kerosene in soil were studied by
Fine et al. (
1997
), Yaron et al. (
1998
) and Dror et al. (
2002
). It was found that
during disposal in the soil-subsurface domain, the light petroleum fractions vol-
atilize or dissolve in the surrounding air and aqueous phases, leaving behind a
nonaqueous liquid phase (NAPL) that contains a heavy hydrocarbon fraction. In
the soil-subsurface domain, the petroleum hydrocarbon NAPL forms entrapped
ganglia that resemble discontinuous blobs within large pores (Schwille
1984
;
Powers et al.
1994
). These ganglia functionally alter the original porous medium
architecture. In the case of kerosene contamination, for example, it was found that
the kerosene residual content (KRC) in soil varies from soil to soil and is inversely
linearly related to the moisture and linearly related to the soil texture as expressed
by clay content (Fig.
18.47
).
Under equilibrium conditions, multicomponent dissolution can be described in
terms of a constant partition coefficient among all of the organic mixture com-
ponents and the aqueous solution. An example of kerosene-water partitioning at
equilibrium was presented in
Chap. 8
(Fig. 8.18), where kerosene was in contact
with an aqueous electrolyte solution (0.01 N NaCl) at a temperature of 22 C for
100 h. From gas chromatogram analysis, it can be seen that aliphatic and branched
aliphatic hydrocarbons in the range C
9
-C
16
comprise the major group of com-
ponents in neat kerosene, with only a minor group of aromatic compounds. In the
aqueous electrolyte solution, aromatic compounds, especially branched benzenes
and naphthalene, make up the majority of the compounds in the aqueous phase.
The C
9
-C
10
aliphatic and branched aliphatic components do not appear in the
chromatogram of the aqueous kerosene, because aromatic components are several
orders of magnitude more soluble than aliphatic components.
