PHYSICO-CHEMICAL INVESTIGATION ON DUMPSITE LEACHATE IN ILORIN METROPOLIS
CHAPTER ONE
1.0 INTRODUCTION
1.1 Background of the study
The municipal solid waste dumpsite (MSWD) examined is located at sawmill, okefomo and irewolede at yidi road street and within Ilorin Metropolis Kwara State. The dumpsites examined contain both biodegradable and non-biodegradable materials of all sorts. The different waste materials may contain different physical, chemical and biochemical properties. In the presence of atmospheric water, high temperature and high microbial populations, these waste materials may decompose and get dissolved in the presence of water to generate a waste liquid substance called leachate. This waste water produced may infiltrate into the ground water aquifer, it may be washed into a nearby surface stream and it may affect soil properties. When humans come into direct contact with such contaminated samples, it may lead to public health problems.
The gradual increasing population and the proliferation of basic industrial processes particularly in major cities of the world has led to civilization that have greater impact on the environment. The disposal of domestic, commercial and industrial garbage in the world is a problem that continues to grow with human civilisation and no method so far is completely safe. Experience has shown that all forms of waste disposal have negative consequences on the environment, public health, and local economies.
Dumpsites are often established in disused quarries, mining or excavated pits away from residential areas. Designated government agency, corporate bodies and some individuals collect wastes routinely into these dumpsites. Here in Nigeria and particularly in Ilorin, modern landfill facilities are not found in these dumpsites; consequently sorting-out of wastes into degradable, non-degradable and recyclable precious materials cannot be achieved. Poor management of dumpsites could create a number of adverse environmental impacts, including wind-blow litter, attraction of mice and pollutants such as leachate, which can pollute underground soil bed, and / or aquifer. Landfill gas mostly composed of methane and carbon dioxide are produced through biodegradation of such waste. Leachate from dumpsites is of particular interest when it contains potentially toxic heavy metals.
Household and industrial garbage may contain toxic materials such as lead, cadmium, mercury, manganese from batteries, insect sprays, nail, polish, cleaners, plastics polyethylene or PVC (polyvinyl chloride) made bottles and other assorted products. Inorganic chemical contamination of the environment is due essentially to anthropogenic source, improper disposal and lack of awareness of the health-risk created by such indiscriminate disposal. Lead, cadmium manganese, arsenic and mercury are pollutants which have unknown physiological benefit when ingested (Abdus-Salam &Adekola, 2005; Brady & Weil, 1999).
There is increase awareness of keeping a friendly hygienic environment and Kwara State government has established an out-fit: Kwara State waste management and control agency for proper collection and disposal of wastes generated through domestic, commercial and industrial activities in all cities in the state. This exercise has increased the number of dumpsites without eliminating the local ones. The build-up of heavy metals in soil from anthropogenic sources has been reported to be harmful to crops and human health (Smith etal., 1996). Sources of these metals ranges from industrially and municipally generated (Gibson & Farmer, 1983; Olajire&Ayodele, 1998), automobile emission (Olajireetal., 2002).
Municipal solid wastes were reported to contain large amount of persistent organic pollutants (Minh etal., 2006). The concentrations and transformations of heavy metals in solid municipal wastes lead to accumulation in the food web (Gimmler etal., 2002). The views of many researchers is that the current trend in the municipal wastes disposal and management practices may increase the heavy metal burden of the soil and underground water (Albores etal., 2000, Okoronkwo, 2006, Elaigwuetal., 2007). Most of these metals have no known physiological relevance to the survival of plants and animals.
This research work was undertaken to ascertain the level of soil pollution of major dumpsites in Ilorin metropolis in order to characterise the nature of waste being generated. Some physico-chemical parameters were also investigated so as to determine the relative mobility of toxic metals in the soil and make appropriate recommendations to Federal Environmental Protection Agency (FEPA) and Kwara State Environmental Protection Agency (KWEPA) on the state of soil pollution of the dumpsites in Ilorin.
1.2 Statement of the problem
Several of the environmental problems in the world today are caused by municipal solidwaste due to its improper management (Huang etal., 1992).Solid wastes can be classified as biodegradable and non-biodegradable. Biodegradability of solid waste is an important factor in handling. Food wastes and wastes of vegetable origin are readily biodegradable, but other organic wastes such as paper and wood are not readily biodegradable. Solid wastes can also be classified as combustible and non-combustible (Olurunfemi&Odita 1998).
The dumpsites examined shows a flow of water through the area which linked to another area.The different wastes types at the dumpsites possess different physical and chemical properties. The leachate produced from the decomposed wastes materials each times it rains may drain into the nearby surface stream, may leach into the sub-surface soil and then into the groundwater aquifers. During this process, the boreholes, stream water and soil samples around the dumpsite may become contaminated. This may be very possible in the study area because the soil texture show that soil around the dumpsite and even outside the dumpsite show very high percentage coarse sand which is highly conducive to leachate transport. From this, it is necessary to determine the physico-chemical characteristics of leachate from the dumpsite which are known to impact human health.
The Poor structure of the cities especially the traditional inner core with their narrow streets and roads may not be motorable as to permit refuse collection truck easy entry and exit. Also the low environmental awareness in Nigeria has a spillover effect on how we manage our solid waste. The general public sees refuse collection and disposal as belonging to government. Consequently, the public treats any call for sustainable solid waste management with disdain if not total apathy. Evidence abounds to show that a lot of ill-formed public flagrantly throw their refuse anywhere and anyhow in the urban centres (Ajadile 2007).Solution to the problems (1) Government should provide more tap water to those areas to reduce contamination (2) Government should provide proper environmental awareness on how to dispose refuse (3)Government should provide good personnel that will effectively plan, execute and monitor dumping of refuse materials in those area.
1.3 Justification
In view of the fact that various studies and research has been made on leachate in different countries which gives an insight awareness of the effect of the presence of heavy metals, high pH, temperature, turbidity and biomarker toxicity parameter. Leachate contains some microorganisms and chemical substances that can harm the body related to public health. Consequently the result from one area may not be applicable in another and not enough to justify the effect in other areas. It is therefore important to study biochemical oxygen demand and chemical oxygen demand of the areas because such research have not been carried out in the area before so as to determine the variation to other areas.
1.4 Research Aim and Objectives
Aim:
⦁ To characterize physico-chemical component on dump leachate sample in Ilorin metropolis.
Objectives:
⦁ To assess the pH, temperature and turbidity properties of leachate in Ilorin.
⦁ To evaluate the presence of heavy metals on leachate samples in Ilorin metropolis.
⦁ To compare the level of biochemical and chemical oxygen demand on leachate samples in Ilorin.
1.5 Research hypothesis
⦁ There is no significant variation in all the samples in study area of collection.
⦁ There is no significant variation in all heavy metals from the study area.
⦁ There is no significant value in biochemical oxygen demand and chemical oxygen demand content from the study area.
1.6 Significance of the study
This study is important because it serves as a medium through which numerous problems associated with the waste dumpsite can be address. This is also necessary because it is hoped that through its outcome, the magnitude of the environmental contamination in the study area will be highlighted.
The outcome of the study may also give the government to appreciate waste management strategies and controls measures over indiscriminate dumping of waste. Furthermore, it is hoped that the findings of this study will motivate other interested researcher in and outside the study area; thus helping to broaden our knowledge which is a prerequisite to formulation of effective control strategies in the future.
Finally, the result of these findings will be included into the limited literature on studies around waste dumpsites.
1.7 Scope of the Study
This study involves the collation and the review of available biochemical data as well as published articles and journals on the leachate of the study area.
⦁ Field trip to the location of the dump site in Ilorin metropolitan.
⦁ Collection of Samples from the dump site.
⦁ Detailed physical and laboratory analysis of samples.
⦁ Result obtained from the physical and laboratory analyses will be integrated with information from literature review to provide a comprehensive data presented and interpreted.
⦁ To identify the major and trace element mineral of each samples.
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