Description
BIODEGREDATION OF
PETROLEUM HYDROCARBON POLLUTED SITES
Petroleum is made of hydrocarbon, hydrocarbon
are compound that is made of hydrogen and carbon. Although it contributes major
percentage to the source of energy used by man on earth, however hydrocarbon
components belong to the family of carcinogens and neurotoxic organic
pollutants. It is well known all over the world that man and his environment is
faced daily with hydrocarbon pollution resulting from oil spillage, petroleum
pipeline linkage, and heavy duty machine repairing workshop as well as oil
drilling and refinery sites, and also due to the increments in underground oil
reservoir discovering and high demand of crude oil all over the world. The
inappropriate drilling, transportation and usage as a matter of fact lead to
increment of soil, air and water body hydrocarbon pollution. If this menace is
not put in check as a matter of urgency, it can cause epidemic outbreak in an
affected communities, shortage in agricultural produces output, threatening of
soil useful microbial biome and environmental disaster. Bioremediation as
promising modern biotechnology is capable of mineralizing hydrocarbon
pollutants into water, carbon dioxide, cells proteins and inorganic compound.
It involves the use of indigenous or genetically modified microbes to break
down organic pollutants into a less toxic form. It not only potent in degrading
organic pollutants, it is cheap compared to chemical and mechanical methods and
also environmental friendly. Therefore, this paper combined and presents a
review of empirical researches done on microbial bioremediation of petroleum
hydrocarbons in different countries.
1. Introduction
Introduction Hydrocarbon carbon contamination
with human environment have been a big threat to human and his natural
surroundings, the conscious and unconscious introduction of harmful substances
into the environment by human through his daily activities, which In return
cause harm to his environment is term pollution. The media that received these
contaminations are soil, water and air ( Agamuthu., et al, 2013). It brings
change in the environment that resulted in way of introducing harmful effects
that altered the quality of human life, animals, plants and microorganisms
(Ewetola, 2013). To
reduce the harms caused by pollution, the three media mention above need to be
subjected to physical, chemical, mechanical or biological treatment (Agamuthu.,
et al, 2013). However
in china, according to (Guangwei,2014
andJayanta Kumar Saha et al.2017) Chinese researchers recently realized how
severed and the extent of pollution on their vast area of soil and it's
negative effects on their farmland. This was estimated to be more than 8% of
china's arable land. This was
reaffirmed by (Mariana .M et al 2010) stating that one fifth of
China’s farmland is polluted, and an area the size of Taiwan is so polluted
that farming should not be allowed there at all. The United States
Environmental Protection Agency most targeted sites of hazardous wastes cleanup
programs are made of 600 of 1408 different kinds of hydrocarbons (Okere
and Semple, 2011; Duan et al.,2013 and Thamaraiselvan et al.2015 ). Soil pollution is considered
to be a life threatening problem because all the plant consumed by human and
the animal is cultivated from the soil, therefore, proper attention most paid
to soil pollution to reduce it to the barest minimal if not totally eliminated.
Although soil remediation is of a high capital and labor intensive project, but
due to man poise for cheaper method for a polluted soil remediation, much have
been done using microorganisms to bio remediate
contaminated soil which proved positive . This method termed to be labor
and capital cheap and environmentally friendly. However, not all bacteria have
the adaptability to degrade pollutants like petroleum hydrocarbon especially in
the soil, according to Zulfa
A et al (2016) it has been proven that microorganisms capability and
adaptability to degrade pollutants, depend on the individual strains to produce
suitable biosurfactans and the formation of biodegrading association that is
very strong and reliable throughout the degradation period. Also, it depend on
the adaptability of the microorganism to carry out its physiological functions under natural
condition that is characterized with limited water supply, low availability of
nutrients and adverse pH condition
