Biotreatment of Crude Oil Contaminated Soil | Chapter 12 | Theory and Applications of Microbiology and Biotechnology Vol. 1
Biodegradation of hydrocarbons by
microorganisms represents one of the primary mechanisms by which petroleum and
other hydrogen pollutants are eliminated from the environment. This work was
carried out on the effect of microorganisms on the biotreatment of oil in crude
oil contaminated soil.
Microorganisms were isolated from two
experimental soil samples contaminated with Bonny Crude and normal
uncontaminated soil as a control over a period of seven months. The microbial
as well as the physico-chemical parameters of the soil samples were all
analyzed using standard methods. Changes in total petroleum hydrocarbon level
were measured appropriately. Treatments used were the microbial isolates.
Forty-four microorganisms were isolated
from the contaminated soils and identified as species of Pseudomonas (7),
Flavobacterium (6), Bacillus (8), Proteus (4), Klebsiella (1), Pencillium (5),
Aspergillus (7), Fusarium (3), Trichypton (2) and Neurospora (1). Ten of the
forty-four isolates had ability to degrade crude oil in the laboratory. On
contamination a value of 1.0X105 cfu/g in microbial counts were
obtained followed by a subsequent increase in population levels after a period
of 2months with a value of 1.0X106 cfu/g. Oil application to the
soil resulted in an increase in total petroleum hydrocarbon from 0.31 ppm to
5.53 ppm; organic matter from 0.41% to 7.34%; available phosphorus from 1.75
ppm to 2.84 ppm. The treatment measures all showed progressive decrease in oil
concentration in the soil. Mixture of bacterial and fungal isolates as a
treatment measure proved to be more favourable above all others, it brought the
concentration from 5.53 ppm to 0.31 ppm after a period of 5 weeks of treatment,
which is same value with the normal soil (uncontaminated).
Species of Pseudomonas, Bacillus,
Flavobacterium, Proteus, Klebsiella, Penicillium, Aspergillus, Fusarium,
Trichyphyton and Neurospora had potential for the degradation of bonny crude
oil. They could therefore be employed in environmental cleanup of petroleum
spill site.
Author(s) Details
B. M. Popoola
Ajayi Crowther University,
Oyo, Oyo State, Nigeria.
A. A. Olanbiwonninu
Ajayi Crowther University,
Oyo, Oyo State, Nigeria.
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