CHAPTER ONE
1.1 Background of
study
For
many years now and many more years to come, the aquatic environment have served
(and will continual to serve) as a stable habitat to various species of plant
and animals ranging from the micro-cellular zooplankton to the more complex
species of fishes and birds. Over the year a natural resource (crude oil) has
been found present both on land and on sea. In Nigeria alone there are about
606 oil fields in the Niger Delta, of which 360 are on-shore and 246 off-shore
(Nwilo and Badejo, 2005). Boasting herself as the largest oil producing country
in Africa and sixth in the world.
This
precious natural resources initially was used as a means of illumination and
lubrication of machine parts against friction but ever since the invention of
the automobile industry and the internal combustion energy, the demand for this
product has increased rapidly. Currently, there are many challenges associated
with the transportation, stockpiling, distribution and production of this raw
materials and its various fractions. In an attempt to make this commodity
reading available for usage, various pollution activities has sufficed ranging
from the contamination of both water and soil environment either by deliberate vandalizing
of oil pipeline used for the transport of crude oil, to the fallout of ships
transporting crude oil from an on-shore to the jetty thereby creating an unbalanced
and stressed aquatic environment.
The
effects of this pollution includes, decreasing the population of aquatic
wildlife , making the water environment unsuitable for domestic and commercial
purpose, also the reduction on the availability of oxygen necessary for growth thus causing death, and the
evaporation of high volatile fraction thus making the site a potential fire
outbreak area. Various clean-up method like the application of chemical
dispersants and controlled burning serves but with little effectiveness as the
atmosphere becomes heavily polluted as in the case of burning and an increase
in greenhouse gases (GHG) also harms the climate. Also by introducing chemical
dispersants the toxicity of the environment is increased even though the spill
is treated, it ‘in returns’ pollutes the environment.
With
a purpose of developing a cleaner and safe technology for the treatment of crude
oil pollution, microbiologist came up with a natural model which could be
stimulated to achieve fast and safer result. Bioremediation is often referred to
as the most natural method of eliminating large amount of oil contaminants from
the environment with the use of a naturally occurring micro- organism to
degrade hazardous crude substance into less toxic or non-toxic compounds. It is
worthy of note that bioremediation is an optimization of a natural process of
biodegradation where micro-organism chemically alter and break down organic
molecules in other substance such as carbon dioxide, fatty acids and water in
order to obtain energy and nutrients. Under bioremediation two distinct processes
may be applied to speed and enhance the process. They include Biostimulation
and Bioaugmentation. Bioaugmentation involves the addition or application of
Hydrocarbon utilizing micro-organism thereby increasing the microbial
population responsible for the clean-up of the polluted site. Specific bacteria
and fungi can be used in this process but bacteria are more commonly used. Biostimulation
involves the addition of appropriate microbial nutrients to a polluted site to
increase the microbial activities of indigenous microbial flora. Some useful
bacteria involved in bioremediation includes pseudomonas, aeromonas, Moraxella, Bilejerirckia, chrobacter, Nocardia,
Streptomyces. In this study the effect of Nutrients specifically Urea and
Nitrogen, Phosphorus and Potassium (N.P.K) on bioremediation will be examined.
Due
to the ever increasing demand globally for crude oil and its various fractions,
pollution of crude oil and its various fractions on both land and sea has been
a major challenge associated with this industry. The need for a cleaner and
better technology which would create a cleaner environment for aquatic wildlife
and terrestrial organization has placed a call for the clean-up technology of
bioremediation. On a crude oil contaminated site, the number of microbes’
present increases rapidly without a subsequent increase in the nutrients
available in the soil or aquatic body, thus a challenge of insufficient
nutrients for proper bioremediation.
Hence, this research studies the
effect of the addition of Nitrogen,Phosphorus,Potassium(N.P.K) fertilizer and Urea
nutrients to contaminated crude oil water
with a cultured stain of bacteria of the pseudomonas
sp on the rate of bioremediation. This biotechnology is very promising as
it makes land or aquatic environment habitable again after the treatment has
been carried out.
To
study the effect of urea and N.P.K on the bioremediation of crude oil
contaminated water.TO achieve this, the following activities were defined and
carried out:
·
To synthesize a crude oil contaminated
water.
·
To culture pseudomonas aeroginosa bacteria.
·
To apply nutrients to this synthesized
crude oil contaminated water containing cultured bacteria
·
To prepare samples with varying quantity
of nutrients.
·
To observe the effect of the nutrients
in the crude oil contaminated water.
·
To determine the Residue Hydrocarbon
Content (RHC) in the crude contaminated water.
This
method of crude oil contamination clean-up is very effective in that it
utilizes naturally occurring micro-organism capable of ‘eating
up’ crude oil and its various fraction depending on some environmental factors
which may include availability of adequate nutrients in the contaminated site. A
thorough understanding of the bioremediation process and the responsible
micro-organism would in a long run help in solving the problem of oil pollution
associated with the oil industry when applied. The proportions of combination
of the nutrients to achieve a balance concentration in the aquatic environment to
be added to any environment so as not lead to eutrophication and so enhance the
bioremediation of crude oil contained site. The importance of this study would
lead to a great reduction in the effects of the pollution caused by oil spill
in Nigeria and the world at large and facilitate the quick recovery of such
site and make them habitable in the shortest possible time.
This
research would consider primarily the biostimulation aspect of bioremediation of
crude oil contaminated water. Nutrients like Nitrogen Phosphorus Potassium
(N.P.K) fertilizer and Urea would be added to an artificially contaminated
crude oil water to carry out the study.