Abstract
Spent/used oil is any oil that has been refined from crude oil, or any synthetic oil that has been used and, as a result of that use, is contaminated by physical or chemical impurities. Examples of used oil include: used motor oil, used hydraulic fluid, used electrical insulating oil, used transmission fluid, used compressor oils, used cutting oils and used coolants. Waste from automobile workshops such as lead acid batteries, gasoline, used asbestos, spent engine oil etc. are discharged indiscriminately in open free land, sewers and gutters and this is channeled to inland and water bodies which affects the growth of plants and microbial diversity when it seeps to the groundwater and also aquatic lives are not spared. In the view of the foregoing, this study therefore seek to examine the concentration of heavy metals in the automobile workshop in Amawbia. The aim of this research is to ascertain the effect of spent oil on the physiochemical properties of soil. Survey design and labor
CHAPTER
ONE
INTRODUCTION
1.1      Background
of the Study
Spent/used oil is any oil that has been refined from crude oil,
or any synthetic oil that has been used and, as
a result of that use, is contaminated by physical or chemical impurities. Examples of used oil include: used motor oil, used hydraulic fluid, used
electrical insulating oil, used
transmission fluid, used compressor oils, used cutting oils and used coolants.
Waste oil Waste oil is defined as anyÂÂÂ
petroleum-based orÂÂÂ
synthetic oil that,
through contamination, has become unsuitable for its original purpose due to
the presence of impurities or loss of original properties.
The difference
between spent/used oil and waste oil, "used
oil" as any petroleum or synthetic oil that has been used, and as a result
of such use is contaminated by physical or chemical properties. "Used
oil" is a precise regulatory term. "Waste oil" is a more generic
term for oil that has been contaminated with substances that may or may not be
hazardous. Any oil contaminated with hazardous waste may itself be a
hazardous waste, and if so, must be managed subject to hazardous waste management
standards. Both used oil and waste oil require proper recycling or disposal to
avoid creating an environmental problem.
The disposal of spent
engine oil (SEO) into gutters, water drains, open vacant plots and farms is a
common practice in Nigeria especially by motor mechanics. This oil, also called
spent lubricant or waste engine oil, is usually obtained after servicing and
subsequently draining from automobile and generator engines and much of this
oil is poured into the soil (Udom, Mbagwu, and Willie, 2018). There are
relatively large amount of hydrocarbons in the used oil, including the highly
toxic polycyclic aromatic hydrocarbons (Adedokun and Ataga, 2017). Also, most
heavy metals such as Lead, Aluminum, and Iron, (Pb, Al, and Fe), which were
below detection in unused lubricating oil, have been reported by (Udo and
Fayemi, 2015) to give high values (ppm) in used oil. These heavy metals may be
retained in soils in the form of oxides, hydroxides, carbonates, exchangeable
cations, and/or bound to organic matter in the soil. Nevertheless, this is
dependent on the local environmental conditions and on the kind of soil
constituents present in the soil-water system. (Amadi, Samuel and Anthony,
2014) have shown that a marked change in properties occurs in soils polluted
with petroleum hydrocarbons, affecting the physical, chemical and
microbiological properties of the soil. Oil pollution of soil leads to build up
of essential (organic C, P, Ca, Mg) and non-essential (Mg, Pb, Zn, Fe, Co, Cu)
elements in soil and the eventual translocation in plant tissues. Although some
heavy metals at low concentrations are essential micronutrients for plants, but
at high concentrations they may cause metabolic disorders and growth inhibition
for most of the plant species. However, plants respond differently to
pollutants.
Okon and Udofot,
(2012) reported that the contamination of soil with spent engine oil caused
growth retardation in plants, with the effect more adverse for tomato
(Lycopersicom esculentum) than pepper (Capsicum annum). Maize (Zea mays), a
major cereal in Nigeria and many African countries, was chosen for this study
because it has become increasingly popular and most farmers have adopted its
cultivation. This study aims to evaluate the effects of spent engine oil on
soil properties. In urban areas, various types of activities like agriculture,
industry and transportation produce large amount of wastes which are classified
as either agricultural, industrial, municipal or nuclear wastes.
These wastes from various
sources are deposited on the soil surfaces either deliberately applied as
fertilizer, sprays or pesticides (Anoliefo and Vwioko, 2015) or inadvertently
through small or large leaks (Ojeniyi, 2010) as solids, plastics, crude oil or
spent engine oil. Some of these wastes can be recycled into some important
products that can be used to meet with the challenges arising from increasing
population of Nigeria. They can be recycled into manures and fertilizers for
production of crops and animals among others (Atuanya, 2017). There are others
that cannot be converted into any beneficial secondary use and therefore pose a
serious threat to the environment and one of such is spent engine oil.
Spent oil sometimes
referred to as waste engine oil is produced from automobile mechanic shops and
mechanical or electrical engine repairers’ shops (Baek and Lee, 2014) after
servicing the vehicles engines, generating set and other types of engines. It
has dark brown to black colour and it is harmful to the soil environment. This
is because it contains a mixture of different chemicals including low to high
molecular weight (C15-C21) compounds, lubricants, additives and decomposition
products and heavy metals which have been found to be harmful to the soil and
human health.