Environmental Engineering Reference
In-Depth Information
Table 7.1
Composition of petroleum received from Bibi-Eybat oil deposit (Absheron)
Fraction
Mass content in crude oil
Boiling range (°C)
Paraffins
C
6
-C
12
15-18
69-230
C
13
-C
25
6-7
230-450
Cycloalkane
C
6
-C
12
19-20
70-230
C
13
-C
23
16-18
230-405
Aromatic hydrocarbons
Mono- and di-cyclic C
6
-C
11
2-3
80-240
Poly-cyclic C
12
-C
18
4
240-400
Naphthene
C
9
-C
25
20-22
180-400
S compounds
< 0.06
Residue
10-12
400
to eliminate as much indigenous microorganisms as possible. The soil was stored
at 4 °C in the dark until required for planting. Soil and nutrient analyses for plant
available phosphorous (colorimetric autoanalyzer), potassium and magnesium
(atomic absorption spectrophotometer), total carbon, organic carbon, inorganic car-
bon, total nitrogen (Leco furnace), NH
4
N, NO
3
-N, NO
2
-N (KCl extractable) and
pH (soil slurry method) were conducted by the Soil and Agriculture Institute under
the Azerbaijan National Academy of Sciences using standard methods. During the
experiment, soil samples were also analyzed according to the Environmental Pro-
tection Agency's (EPA) standard methods (
2000
) using spectrophotometric infrared
(method # 418.1) to assess total petroleum hydrocarbon content (TPH) and GC-MS
(method # 610) to assess PAH content.
Three hundred gram dry weight of soil were placed in 10-cm diameter ceramic
pots with a drainage hole in the bottom, and brought to approximately 9-10 % grav-
imetric water content with sterile distilled water. Pots were equilibrated in a growth
room for 7 days prior to planting. Moist was kept at 9-10 % by addition of sterile
distilled water. Introduction of contaminants (Absheron petroleum, 10,000 ppm,
Table
7.1
), inoculation of hydrocarbon degrading microbial consortia and/or bio-
surfactant started 2 and 1 day, respectively, before planting. Sampling was done at
weekly intervals for 7 weeks following planting.
2.2 Plants
The choice of plant species for remediation is an important consideration that will
surely affect the outcome of contaminant degradation. It has to depend on the type
of contaminants, their concentrations and distribution of contaminants again. Since
contaminants must be in contact with plant roots, so the depth and density of plant
roots must be considered (Tsao
2003
). Perennial ryegrass (
Lolium perenne
) is often
