Investigation on the Heavy Metal Concentrations and Potential Ecological Risk Assessment of Sediments from Ikpoba River, Benin City, Edo State, Nigeria

Authors: Idemudia I, Omoigberale MO, Uyi OO

DOI Info: N/A

ABSTRACT

This study investigated the monthly variations of the heavy metal concentrations of sediments from Ikpoba River, Benin City, Nigeria. A further objective of this study was to determine the potential ecological risk assessment of sediments from the same river. Sediments obtained from four sampling stations across the river were analysed for heavy metals between November 2016 and February 2017. Nine heavy metals in the sediment samples were determined by atomic absorption spectrophotometry (AAS). Apart from Cu, Cd, Ni and V which showed significant differences across the various stations, all other heavy metals did not differ as a function of sampling station. Heavy metal assessment and ecological risk assessment were carried out to determine the pollution and risk degree of the heavy metals in the sediments. Heavy metal assessment revealed that Cr, Cu, Cd and Pb were present in high levels across all four stations. Ecological risk assessments conducted to determine the potential ecological index (Eⁱ_R) and comprehensive potential ecological risk index (RI) revealed that Cd had a very strong to an extremely strong degree of pollution across the study stations thus resulting in the extremely strong degree of risk in stations 1, 3 and 4. The results suggest that the studied stations in Ikpoba River are highly polluted, but whether other stations of the river are also polluted remains unclear, and therefore warrant further studies.

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