Abstract: Brass terminal, one of the several crude oil and
petroleum products storage/handling facilities in the Niger Delta was
built in the 1980s. Activities at this site, over the years, released
crude oil into this 3 m-deep, 1500 m-long canal lying adjacent to the
terminal with oil floating on it and its sediment heavily polluted. To
ensure effective clean-up, three major activities were planned: site
characterization, bioremediation pilot plant construction and testing
and full-scale bioremediation of contaminated sediment / bank soil by
land farming. The canal was delineated into 12 lots and each
characterized, with reference to the floating oily phase, contaminated
sediment and canal bank soil. As a result of site characterization, a
pilot plant for on-site bioremediation was designed and a treatment
basin constructed for carrying out pilot bioremediation test.
Following a designed sampling protocol, samples from this pilot
plant were collected for analysis at two laboratories as a quality
assurance / quality control check. Results showed that Brass Canal
upstream is contaminated with dark, thick and viscous oily film with
characteristic hydrocarbon smell while downstream, thin oily film
interspersed with water was observed. Sediments were observed to be
dark with mixture of brownish sandy soil with TPH ranging from
17,800 mg/kg in Lot 1 to 88,500 mg/kg in Lot 12 samples. Brass
Canal bank soil was observed to be sandy from ground surface to 3m,
below ground surface (bgs) it was silty-sandy and brownish while
subsurface soil (4-10m bgs) was sandy-clayey and whitish/grayish
with typical hydrocarbon smell. Preliminary results obtained so far
have been very promising but were proprietary. This project is
considered, to the best of technical literature knowledge, the first
large-scale on-site bioremediation project in the Niger Delta region,
Nigeria.
Abstract: Ibeno, Nigeria hosts the operational base of Mobil
Producing Nigeria Unlimited (MPNU), a subsidiary of ExxonMobil
and the current highest oil & condensate producer in Nigeria. Besides
MPNU, other oil companies operate onshore, on the continental shelf
and deep offshore of the Atlantic Ocean in Ibeno, Nigeria. This study
was designed to delineate oil polluted sites in Ibeno, Nigeria using
geophysical methods of electrical resistivity (ER) and ground
penetrating radar (GPR). Results obtained revealed that there have
been hydrocarbon contaminations of this environment by past crude
oil spills as observed from high resistivity values and GPR profiles
which clearly show the distribution, thickness and lateral extent of
hydrocarbon contamination as represented on the radargram reflector
tones. Contaminations were of varying degrees, ranging from slight
to high, indicating levels of substantial attenuation of crude oil
contamination over time. Moreover, the display of relatively lower
resistivities of locations outside the impacted areas compared to
resistivity values within the impacted areas and the 3-D Cartesian
images of oil contaminant plume depicted by red, light brown and
magenta for high, low and very low oil impacted areas, respectively
confirmed significant recent pollution of the study area with crude
oil.
Abstract: The microbiological and physicochemical
characteristics of wetland soils in Eket Local Government Area were
studied between May 2001 and June 2003. Total heterotrophic
bacterial counts (THBC), total fungal counts (TFC), and total
actinomycetes counts (TAC) were determined from soil samples
taken from four locations at two depths in the wet and dry seasons.
Microbial isolates were characterized and identified. Particle size and
chemical parameters were also determined using standard methods.
THBC ranged from 5.2 (+0.17) x106 to 1.7 (+0.18) x107 cfu/g and
from 2.4 (+0.02) x106 to 1.4 (+0.04) x107cfu/g in the wet and dry
seasons, respectively. TFC ranged from 1.8 (+0.03) x106 to 6.6 (+
0.18) x106 cfu/g and from 1.0 (+0.04) x106 to 4.2 (+ 0.01) x106 cfu/g
in the wet and dry seasons, respectively .TAC ranged from 1.2
(+0.53) x106 to 6.0 (+0.05) x106 cfu/g and from 0.6 (+0.01) x106 to
3.2 (+ 0.12) x106 cfu/g in the wet and dry season, respectively.
Acinetobacter, Alcaligenes, Arthrobacter, Bacillus, Beijerinckja,
Enterobacter, Micrococcus, Flavobacterium, Serratia, Enterococcus,
and Pseudomonas species were predominant bacteria while
Aspergillus, Fusarium, Mucor, Penicillium, and Rhizopus were the
dominant fungal genera isolated. Streptomyces and Norcadia were
the actinomycetes genera isolated. The particle size analysis showed
high sand fraction but low silt and clay. The pH and % organic
matter were generally acidic and low, respectively at all locations.
Calcium dominated the exchangeable bases with low electrical
conductivity and micronutrients. These results provide the baseline
data of Eket wetland soils for its management for sustainable
agriculture.