Seasonal variation of heavy metal speciation in soil and stream sediments from hospital waste dumpsite in Ilesa, Southwestern Nigeria

Fakoya O. T.; Oluyemi E. A.; Olabanji I. O.; Eludoyin A. O.; Makinde O. W.; Oyinloye J. A.

doi:10.5897/AJEST2017.2322

African Journal of
Environmental Science and Technology

Abbreviation: Afr. J. Environ. Sci. Technol.
Language: English
ISSN: 1996-0786
DOI: 10.5897/AJEST
Start Year: 2007
Published Articles: 1126

Full Length Research Paper

Seasonal variation of heavy metal speciation in soil and stream sediments from hospital waste dumpsite in Ilesa, Southwestern Nigeria

Fakoya O. T.

Fakoya O. T.
Department of Chemistry, Faculty of Science, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria.
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Oluyemi E. A.

Oluyemi E. A.
Department of Chemistry, Faculty of Science, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria.
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Olabanji I. O.

Olabanji I. O.
Department of Chemistry, Faculty of Science, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria.
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Eludoyin A. O.

Eludoyin A. O.
Department of Geography, Faculty of Social Sciences, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria.
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Makinde O. W.

Makinde O. W.
entre for Energy Research and Development, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria.
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Oyinloye J. A.

Oyinloye J. A.
Department of Chemistry, Faculty of Science, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria.
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Article Number - 1D2814558465
Vol.12(9), pp. 312-322 , September 2018
https://doi.org/10.5897/AJEST2017.2322

Received: 10 March 2017
Accepted: 17 August 2017
Published: 30 September 2018

Abstract

A speciation study of selected heavy metals in soil and stream sediments around a hospital waste dumpsite was investigated. Sequential extraction procedure was used to fractionate the metals into 4 fractions: Exchangeable and bound to carbonate, oxyhydroxide of Fe and Mn, organic matter and the residual fraction. Speciation analysis of Fe, Mn, Zn, Cu, Cd and Pb in soil revealed that a major portion of the metals were associated with the residual fraction. The exchangeable and carbonate fraction was the most important fraction for Mn_(Dry/Wet)and Zn_(Dry/Wet)with an average of (27%, 35.6%) Mn and (20.8%, 27.3% ) Zn. Cd, Fe and Cu were associated with the oxyhydroxide of Fe and Mn fraction with an average of (61%, 44.2%) Cd_(Dry/Wet), (41%, 21%) Fe_(Dry/Wet)and (25.3%, 22.5%) Cu_(Dry/Wet).A significant amount of Pb_(Dry/Wet)(10.7%, 21.8%) was bound to organic fraction during dry and wet season respectively. In sediments, Mn_(Dry/Wet)occurred mainly in exchangeable and carbonate fraction (45.2%, 29.3%), Fe_(Dry/Wet)and Cd_(Dry/Wet)in the oxyhydroxide of Fe and Mn fraction were (41%, 31.2%) and (26.6%, 93.6%) respectively and the amount of Pb_(Dry/Wet)bound to the organic fraction was (86.9%, 27.3%). A significant amount of Cu_(Dry/Wet)(20.8%, 29.4%) was bound to the organic fraction and Zn_(Dry/Wet)(35.5%, 73%) was retained in the residual fraction. In soil and sediments, Mn was potentially more bioavailable. However, the level of lead in organic matter fraction of soil suggest that it may be remobilized under oxidizing condition, hence, bioavailable.