Environmental Engineering Reference
In-Depth Information
Chapter 10
Reciprocal Effects of Oil-contaminated Soil
and
Festuca
(Tall fescue)
Dariush Minai-Tehrani, Saeed Minoui and Malak Hossein Shahriari
Abstract
Contamination of soil by crude oil can damage ecosystem and environ-
ment. The oil can cause damage to the plants, the first element in food cycle. On
the other hand, there are some plants that can be used to remediate crude oil-con-
taminated soil. Some plants such as grasses have been demonstrated to have better
capacity in biodegradation of oil in the soil. In this study, the effect of different
concentrations of light crude oil (1-10 %) on the growth and germination of
Festuca
arundinacea
(Tall fescue) was studied for 120 days. The results showed that percent
germination and dry biomass of the plants decreased by increasing light crude oil
concentration in the soil. The total biomass (root + shoot) was higher (2.1 g) in 1 %
crude oil sample while it was lower (0.06 g) in 10 % crude oil sample. The length
of leaves decreased in higher crude oil concentration compared with that in control
(27 cm). Total colony and oil-degrading colony count in soil showed that the micro-
bial population in 7 and 10 % oil samples was higher than those in the control and
low concentrations of crude oil. On the other hand, the effect of the plant on crude
oil reduction was also studied and compared in vegetated and non-vegetated oil-
contaminated soil. The crude oil reduction in the vegetated and the non-vegetated
samples was higher in 1 % oil sample. All vegetated samples had higher crude oil
reduction than the non-vegetated samples. The higher reduction (73 %) occurred at
1 % sample, while the lower reduction (24 %) was seen at 10 % oil sample. In con-
clusion,
Festuca arundinacea
as a grass could tolerate high concentration of light
crude oil in soil and is a suitable plant for phytoremediation of oil-contaminated
soil. However high concentration of oil could affect its growth and germination,
reducing the root distribution in soil and causing untimely chlorosis.
