Application of Natural Radionuclide in the Subsurface Hydrogeology of Selected Two Local Governments in South Western Nigeria

Jeje Julius Olatunji; Muritala Oluwaseun Arowolo; Adeniyi Ayokunle Sodipo

doi:10.37284/eaje.2.1.148

Jeje Julius Olatunji, PhD Obafemi Awolowo University
Muritala Oluwaseun Arowolo Obafemi Awolowo University
Adeniyi Ayokunle Sodipo Obafemi Awolowo University

DOI: https://doi.org/10.37284/eaje.2.1.148

Keywords: Radioactive Isotopes, Residence Time, Geological Formation, Gamma-Ray, Spectrometer, Oxidation State

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Abstract

This research investigated the use of radioactive isotopes to study the underground water characteristics of Ife South and Ife North Local governments area of Osun state in Southwestern Nigeria. The study aimed to determine the origin of water, the flow paths, residence time, and prediction of the geological formation of the study area. Twelve water samples were collected from the two local governments using standard methods for isotope study. Uranium ²³⁴U and²³⁸U were analyzed for water samples using a gamma-ray spectrometer with Caesium Iodide (CsI) scintillation detector and physical analyses such as pH, electrical conductivity, total dissolved solids, and temperature were also determined. The specific activity of ²³⁸U ranged between 27.44±0.55 to 36.89±1.70 Bq/kg; activity ratio of water samples from the two LGA ranged from 0.83 to 1.07 with average activity ratio of 0.901. All the sample locations have an activity ratio of less than 1.00 except two locations in Ife South LGA (Ooni 1 and 2); a ²³⁴U value of 30.386747 Bq/kg was taken as constant. Ife North and Ife South have an average EC, turbidity, TDS, residence time of 493.3 (µs/cm), and 686.6 (µs/cm); 1.2 NTU and 3.33 NTU; 108.67 mg/l and 523.33 mg/l; 2.889 ma and 2.784 ma respectively. In conclusion, the groundwater of the two LGA originate from the same source and are in the oxidation state; aquifers within Ife North and Ife South are separated with a barrier; hence its groundwater does not flow through one another. The residence time of groundwater in the two LGA is over 2.8 ma; Ooni 1 and 2 area is underlain by rocks rich in Uranium (granite), rocks underlying Ife South is younger to Ife North, Ife North is underlying by old weathered rocks (sedimentary rocks).

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References

Geyh M. A. (2003). Radiocarbon dating of old groundwater - history, limits, and future. International Symposium on Isotope Hydrology and Integrated Water Resources Management (pp. 23-24). Vienna: International Atomic Energy Agency.

International Atomic Energy Agency. (2004). Managing water resources using isotope hydrology. International Atomic Energy Agency. Retrieved from https://www.iaea.org/sites/default/files/water.pdf

Lal, D. (2004). Hydrological process studies using cosmic-ray produced radionuclides. Isotope Hydrology and Integrated Water Resources Management, 13.

Ma, J., Ding, Z., Edmunds, W. M., Gates, J. B., & Huang, T. (2009). Limits to recharge of groundwater from Tibetan plateau to the Gobi Desert, implications for water management in the mountain front. Journal of Hydrology, 364(1-2), 128-141.

Maduabuchi, C., Faye, S., & Maloszewski, P. (2006). Isotope evidence of palaeorecharge and palaeoclimate in the deep confined aquifers of the Chad Basin, NE Nigeria. Science of the total environment, 370(2-3), 467-479.

Montoroi, J. P., Grünberger, O., & Nasri, S. (2002). Groundwater geochemistry of a small reservoir catchment in Central Tunisia. Applied Geochemistry, 17(8), 1047-1060.

Rahaman M. (1988). Recent advances in the study of the Basement Complex of Nigeria. In Precambrian Geology of Nigeria, 11-43.

Shiklomanov, I. A., & Rodda, J. C. (Eds.). (2004). World water resources at the beginning of the twenty-first century. Paris: Cambridge University Press.