IJG  Vol.3 No.2 , May 2012
Groundwater Contamination Prediction Using Finite Element Derived Geoelectric Parameters Constrained by Chemical Analysis around a Sewage Site, Southwestern Nigeria
ABSTRACT
Vertical Electrical Sounding, the Finite Element Technique (FET) and chemical analysis of soil samples were used to map the pollution plume around two oxidation sewage ponds in Ile-Ife, Southwestern Nigeria. The elemental concentrations of the soil samples at 5 m depth around the sewage ponds were obtained using partial extraction of exchangeable metals ions of (0.05 HCl + 0.025 N H2SO4) or 0.075 N acid mixture. The VES interpreted results delineated three to four geoelectric subsurface layers comprising topsoil, laterite, weathered layer and the fresh basement. The elemental concentration of Cu, Zn, Pb and Cr in the soil samples located at the periphery of the sewage ponds are much higher than those of the control sample point indicating pollution. The finite element generated isopach map of the overburden indicates easterly direction of groundwater flow and weathered layer isoresistivity map generated using the finite element technique identifies low resistivity zone characteristic of pollution zone in the eastern flank. The study concluded that the groundwater in the area around the sewage ponds may have been polluted.

Cite this paper
O. G. Bayowa, D. E. Falebita, M. O. Olorunfemi and A. A. Adepelumi, "Groundwater Contamination Prediction Using Finite Element Derived Geoelectric Parameters Constrained by Chemical Analysis around a Sewage Site, Southwestern Nigeria," International Journal of Geosciences, Vol. 3 No. 2, 2012, pp. 404-409. doi: 10.4236/ijg.2012.32045.
References
[1]   D. K. Todd, “Groundwater Hydrology,” Reprints Edition, John Wiley and Sons Inc., New York, 1959, p. 336.

[2]   J. S. Donaldson, “Electrical Methods of Detecting Contaminated Groundwater at the Stringfellow Waste Disposal Site, Riverside Country, California,” Environmental Geology and Water Sciences, Vol. 6, No. 1, 1984, pp. 11-20. doi:10.1007/BF02525565

[3]   N. S. Subba Rao, V. V. S. Gurunadha Rao and C. P. Gupta, “Groundwater Pollution Due to Discharge of Industrial Effluents in Ven-Katapura Area, Visakhapatnam, Andhra Pradesh, India,” Environmental Geology, Vol. 33, No. 4, 1997, pp. 289-294. doi:10.1007/s002540050248

[4]   W. B. Nixon and R. J. Murphy, “Waste Site Hazard Assessment: A Taxonomy of Current Methods and Criteria,” Environmental Engineering and Policy, Vol. 1, 1998, pp. 59-74. doi:10.1007/s100220050006

[5]   A. Adepelumi, B. Ako and T. Ajayi, “Groundwater Contamination in the Basement-Complex Area of Ile-Ife, Southwestern Nigeria: A Case Study Using the Electrical-Resistivity Geophysical Method,” Hydrogeology Journal, Vol. 9, No. 6, 2001, pp. 611-622. doi:10.1007/s10040-001-0160-x

[6]   A. A. Adepelumi, B. D. Ako, O. Afolabi and J. B. Arubayi, “Delineation of Contamination Plume around Oxidation Sewage-Ponds in Southwestern Nigeria,” Environmental Geology, Vol. 48, No. 8, 2005, pp. 1137-1146. doi:10.1007/s00254-005-0056-5

[7]   M. A. Rahaman and O. O. Ocan, “On Relationship in the Precambrian Migmatite Gneiss of Nigeria,” Journal of Mining and Geology, Vol. 15, 1978, pp. 23-30.

[8]   E. T. Okhue and M. O. Olorunfemi, “Electrical Resistivity Investigation of a Typical Basement Complex Area,” Journal of Mining and Geology, Vol. 2, 1992, pp. 63-68.

[9]   P. A. Oluwande, “Cheap Sewage Disposal in Developing countries,” Ibadan University Press, Ibadan, 1978, pp. 46-49.

[10]   P. Munsiri, C. E. Boyd and B. J. Hajek, “Physical and Chemical Characteristics of Bottom Soil Profiles in Ponds at Auburn, Alabama, and a Proposed Method for Describing Pond Soil Horizons,” Journal of the World Aquaculture Society, Vol. 26, No. 4, 1995, pp. 346-377. doi:10.1111/j.1749-7345.1995.tb00831.x

[11]   C. E. Boyd and P. Munsiri, “Phosphorus Adsorption Capacity and Availability of Added Phosphorus in Soils from Aquaculture Areas in Thailand,” Journal of the World Aquaculture Society, Vol. 27, 1996, pp. 160-167. doi:10.1111/j.1749-7345.1996.tb00265.x

[12]   C. E. Boyd, C. W. Wood, T. Thunjai and S. Sonnenholzner, “Pond Soil Characteristics and Dynamics of Soil Organic Matter and Nutrients,” In: K. McElwee, D. Burke, M. Niles, X. Cummings, and H. Egna (Eds.), 17th Annual Technical Report. Pond Dynamics/Aquaculture CRSP, Oregon State University, Corvallis, 2000, pp. 1-8.

[13]   P. Keary and M. Brooks, “An Introduction to Geophysical Exploration,” Blackwell, Oxford, 1984.

[14]   R. Fenner, “Finite Element Method for Engineers,” Macmillan Press Ltd., London, 1975, pp. 31-44.

[15]   A. A. Agbede, “The Finite Elements Analysis of the Opa River Dam,” Unpublished MSc Thesis, Obafemi Awolowo University, Ile-Ife, 1981, p. 32.

[16]   H. F. Wang and M. P. Anderson, “Groundwater Modelling with Finite Difference and Finite Element Methods,” Elsevier Publishing, Amsterdam, 1982, pp. 1-137.

[17]   A. A. Adepelumi, M. O. Olorunfemi, D. E. Falebita and G. O. Bayowa, “Structural Mapping of Coastal Plain Sands Using Engineering Geophysical Technique: Lagos, Nigeria Case Study,” Natural Science, Vol. 1, No. 1, 2009, pp. 2-9. doi:10.4236/ns.2009.11002

[18]   D. W. Urish, “The Practical Application of Surface Electrical Resistivity to Detection of Ground-Water Pollution,” Groundwater, Vol. 21, 2006, pp. 144-152. doi:10.1111/j.1745-6584.1983.tb00711.x

 
 
Top