Assessment Of Selected Trace Elements Concentration in Eleyele Lake-Water, Ibadan South Western Nigeria

Assessment Of Selected Trace Elements Concentration in Eleyele Lake-Water, Ibadan South Western Nigeria Kunle-John, I. O., Michaels, S. P., and Okay E. N.
National Water Resources Institute, Kaduna Abstract Eleyele Lake has enormous economic importance as it is completely surrounded by various communities which discharge their domestic waste directly into the lake. This alters the physical, chemical and biological characteristics of the lake. It is essential to assess the water for its various usage. Twelve (12) samples were collected from various locations of the lake and analysed. Some physical parameters (electrical conductivity, Total Dissolved Solids, Ph and temperature were determined in-situ. The rest of the sample was taken to the laboratory for various chemical analysis and the results were compared to the WHO standards. The chemical extent of the contamination was determined by the contamination factor, degree of contamination and Geo-Accumulation Index. The physical parameters show that the TDS has an average of 122.2ppm and EC was uniform throughout the various points of reading suggesting that the lake is fresh water. The pH averaged at 72, temperature at 27.2 degrees. The selected trace element falls within the WHO acceptable limits. Their contamination indices showed that Ba, Co, Cs, Cu, Mo, Rb, Sr and Zn are generally less than one depicting their geogenic origin. The high degree of contamination is influenced by high levels of Al and Fe due to human activities and industrial waste disposal and can lead to anemia, osteomalacia (brittle or soft bones), cardiac arrest, stomach problems, nausea, and hemochromatosis. Thus, Eleyele lake is not advisable for consumption. Key words: Eleyele lake, Contamination factor, Geo-Accumulation Index Trace elements concentration,

INTRODUCTION Eleyele Lake serves a great economic importance; it provides water for domestic agricultural and industrial use, supporting subsistence and artisanal fisheries. It is completely surrounded by various communities that discharge their domestic waste directly into the lake water. When wastes from different sources are discharged into the water body that alter the physical, chemical and biological characteristics of the water body in such a way that it may not be useful for the purpose for which it is intended. Environmental pollutants arising from anthropogenic source have the potential to affect the aquatic ecosystem in a synergistic manner. The productivity and growth of aquatic organisms depend on the physicochemical characteristics of the water body and maximum productivity can only be obtained at optimal levels of physico- chemical parameters. It is therefore very essential and important to test the water before it is used for drinking, domestic, agricultural or industrial purposes. Quality assessment involves the analysis of physico- chemical, biological and microbiological parameters that reflect the biotic and abiotic status of the ecosystem. Water quality Kunle-John, I. O., Micheals, S. P., and Okay, E. N. Water Resources Vol. 34 No.2 (2024) 190 – 210
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monitoring has a high priority for the determination of current use. The usefulness of water depends on whether such waters are timely, quantitatively and qualitatively available according to Bhatia (2010).
The sources of water for any specific purpose are not as important as the suitability of the water for the desired purpose. With increasing human population, industrialization. urbanization and the consequent increase in demand for water for both domestic and industrial uses, the attendant increase in the implication of polluted water on man and the environment have been severally studied (Asiwaju-Bello and Akande. 2004: Ige et al., 2008) High inputs and presence of trace metals contaminants in water could pose serious problems resulting in potential long-term toxic implication on the environment and the ecosystem. When the main water body of a town is contaminated by heavy metals and trace elements in general, it has a direct effect on that environment and ecosystem. The aim of the study is to assess the potential impact of selected trace metals found in Eleyele lake on groundwater in parts of Ibadan Southwestern Nigeria.
Location of the Study Area This study was carried out in Eleyele (Figure 1), which is located in the northeastern part of Ibadan city, southwestern Nigeria within longitude 3° 33’E and latitude 7 25 18" N-7 26 48’ N. The artificial lake was constructed in 1942 to provide raw water to provide a potable water supply for major parts of Ibadan metropolis. The lake and associated dams at Eleyele receive water from the River Alapata and headstream of River Onal.

Figure 1: Location map of Study Area showing sample collecti