JWARP  Vol.1 No.3 , September 2009
Hydrogeochemical Assessment of Metals Contamination in an Urban Drainage System: A Case Study of Osogbo Township, SW-Nigeria
ABSTRACT
With increasing urban population, attention had been focused on environmental degradation of urban drain-age system with respect to trace/heavy metal contaminations. Such concerns underlie the ever-increasing impacts of urbanization and industrial activities on urban watershed in the developing regions of the world, especially in areas with inadequate land-use plan and poor waste disposal and management practices. Hence, this study highlights the hydrogeochemical assessment of surface water and bottom-sediment samples from an urban drainage system in Osogbo Township, SW-Nigeria with respect to trace metals contaminations. The results show that the surface water samples have generally low TDS with average value of 362mg/l, while the average dissolved concentrations of the trace metals (Cu, Pb, Zn, Ni, As and Cr) vary from 0.01 to 0.5mg/l. Cu, Cr and As exhibit concentrations similar to the local background concentrations (LBC) in the pristine stream water with low single metal contamination factor (CF ≈ 1). Pb, Zn and Ni are 5 folds enriched with contamination factor (CF) of >5 indicating moderate to high contamination. For the sediment phase, the adsorbed concentrations of the trace metals (Cu, Pb, Zn, Ni, As, Cr and Co) vary between 0.1 to 3.1mg/kg. These represent about 1 to 3% of the respective total metal concentrations with average values of 18.2– 533.4mg/kg. Also low anthropogenic factor, AF (0.002 to 0.08) and mostly negative values (–5 to –15) of Mueller’s geo-accumulation index (Igeo) for adsorbed metal contents in the sediments suggest dominant geo-genic controls. However, the total metals concentrations in the sediment phase have high estimated AF of 1.1 to 9.3 and positive values of the estimated Igeo (0.9–2.0) and metal contamination index (MCI) of 2.5–8.3. All these suggest a medium to high level enrichment (of 2 to 10 factor) for most of the metals with respect to the local background concentration (LBC) in the basement bedrock units (with the exception of Cr and Ni). This is consistent with the preferential metal enrichment in the sediment phase as indicated by the estimated parti-tioning/distribution coefficient, Kd of >1 exhibited by the total metal concentrations in the stream sediment. Nonetheless, the correlated high peaks of electrical conductivity of the stream water samples and adsorbed concentrations of some trace metals within the urban stretches are indications of point source inputs of un-treated sewage into the drainage system.

Cite this paper
nullM. TIJANI and S. ONODERA, "Hydrogeochemical Assessment of Metals Contamination in an Urban Drainage System: A Case Study of Osogbo Township, SW-Nigeria," Journal of Water Resource and Protection, Vol. 1 No. 3, 2009, pp. 164-173. doi: 10.4236/jwarp.2009.13021.
References
[1]   A. G. Darnley, “International geochemical mapping: A new global project,” In: A. G. Darnley, A. G. Garrett, (Eds.), International Geochemical Mapping. Jour. Geochem. Explor., Vol. 39, pp. 1–14. 1990.

[2]   M. D. Cocker, “Geochemical mapping in Georgia, USA: A tool for environmental studies, geologic mapping and mineral exploration,” Jour. Geochem. Explor., Vol. 67, pp. 345–360, 1999.

[3]   P. N. Ranasinghe, G. W. A. R. Fernando, C. B. Dissanayake, and M. S. Rupasinghe, “Stream sediment geochemistry of the Upper Mahaweli River Basin of Sri Lanka—Geological and environmental significance,” Journal of Geochemical Exploration, Vol. 99, pp. 1–28, 2008.

[4]   J. O. Nriagu, “Global inventory of natural and anthropogenic emissions of trace metals to the atmosphere,” Nature, Vol. 279, pp. 409–411, 1979.

[5]   J. O. Nriagu and J. M. Pacyna, “Quantitative assessment of worldwide contamination of air, water, and soils by trace metals,” Nature, Vol. 33, pp. 134–139, 1988.

[6]   H. E. Allen, “Standards for metals should not be based on total metal concentrations,” SETAC-Europe News, Vol. 8, pp. 7–9, 1997.

[7]   M. G. Vijver, J. Spijker, J. P. M. Vink, and L. Posthuma, “Determining metal origins and availability in fluvial deposits by analysis of geochemical baselines and solid-solution partitioning measurements and modeling,” Environmental Pollution, Vol. 156, pp. 832–839, 2008.

[8]   J. Viersa, B. Dupréa, and J. Gaillardet, “Chemical composition of suspended sediments in World Rivers: New insights from a new database,” Science of the Total environment, Vol. 407, pp. 853–868, 2009.

[9]   W. Salomon and U. Foerstner, “Metals in the hydrocycle,” Springer-Verlag, Berlin Heidelberg, New York. 1984.

[10]   M. A. Olade, “Heavy metal pollution and the need for monitoring: Illustrated for developing countries in west Africa,” In: Hutchinson T, Meema K, editors. Lead, Mercury, Cadmium and Arsenic in the environment, Scope, John Wiley and Sons., pp. 335–341, 1987.

[11]   J. L. Mogollon, C. Bifano, and B. E. Davies, “Geochemistry and anthropogenic inputs of metals in a tropical lake in Venezuela,” Appl Geochem, Vol. 11, pp. 605–616, 1996.

[12]   P. C. Paul and K. C. Pillai, “Trace metals in a tropical river environment-distribution,” Water Air Soil Pollute., Vol. 19, pp. 63–73, 1983.

[13]   R. J. Gibbs, “Transport phases of transition metals in the Amazon and Yukon Rivers,” Geol. Soc. Am. Bull., Vol. 88, pp. 829–843, 1977.

[14]   G. Mueller, “Schwermetalle in den Sedimenten des Rheins–Veraenderungen seit 1971,” Umschau., Vol. 79, pp. 778–783, 1979.

[15]   G. Mueller, “Die Schwermetallbelastung der Sedimenten des neckars und Seiner Nebenfluesse,” Chemiker-Zeitung, Vol. 6, pp. 157–164, 1981.

[16]   M. A. Rahaman, “Review of the basement geology of southwestern Nigeria,” In C. A. Kogbe, (Ed) Geology of Nigeria. Elizabethan Publishers, Lagos, Nigeria. pp. 41–58, 1976.

[17]   M. O. Oyawoye, “The basement complex of Nigeria,” In: T. F. J. Dessauragie, and Whiteman (Eds), African Geology. Ibadan University Press, Nigeria, pp. 67–78, 1970.

[18]   I. B. Odeyemi,.“A review of orogenic events in the Precambrian Basement of Nigeria, West Africa,” Geologische Rundschau, Vol. 70, No. 3, pp. 897–909, 1981.

[19]   J. D. Stednick, “Wildland water quality sampling and analysis,” Academic Press Inc., San Deigo, 216p, 1991.

[20]   R. A. Sutherland, “Bed sediment-associated trace metals in an urban stream, Oahu, Hawaii,” Environ Geol., Vol. 39, pp. 611–627, 2000..

[21]   K. Loska, D. Wiechula, and I. Korus, “Metal contamination of farming soils affected by industry,” Environment International, Vol. 30, pp. 159–165, 2004.

[22]   M. Meybeck, A. J. Horowitz, and C. Grosbois, ”The geochemistry of Seine River Basin particulate matter: Distribution of an integrated metal pollution index,” Sci. Tot. Environ., Vol. 328, pp. 219–236, 2004.

[23]   M. N. Tijani, K, Jinno, and Y. Hiroshiro, “Environmental ompacts of heavy metal distribution in water and stream sediments of Ogunpa river Ibadan, SW Nigeria,” Jour. Mining and Geol., Vol. 40, No. 1, pp. 73–83, 2004.

[24]   L. Hakanson, “An ecological risk index for aquatic pollution control—A sedimentological approach,” Water Res. Vol. 14, pp. 975–1001, 1980.

[25]   J. H. Trefry, S. Metz, and R. P. Trocine, “A decline in lead transport by Mississippi River,” Science, Vol. 230, pp. 439–441, 1985.

[26]   S. J. Schropp, F. G. Lewis, H. L. Windom, J. D. Ryan, F. D. Calder, and L. C. Burney, “Interpretation of metal concentrations in estuary sediments of Florida using aluminum as a reference element,” Estuaries, Vol. 13, pp. 227–235, 1990.

[27]   K. C. Sahu and U. Bhosale, “Heavy metal pollution around the island city of Bombay, India-Part I: Quantification of heavy metal pollution of' aquatic sediments and recognition of environmental discriminants,” Chemistry Geology, Vol. 9l, pp. 263–283, 1991.

[28]   M. Singh, A. A. Ansari, G. Mueller, and I. B. Singh, ”Heavy metals in freshly deposited sediments of the Gomati River (a tributary of the Ganga River): Effects of human activities,” Environ Geol., Vol. 29, pp. 247–252, 1997.

[29]   B. R. Manjunatha, K. Balakrishna, R. Shankar, and T.R. Mahalingam, “Geochemistry and assessment of metal pollution in soils and river components of a monsoon dominated environment near Karwar, southwest coast of India,” Environ Geol., Vol. 40, pp. 1462–1470, 2001.

 
 
Top