Assessment of Heavy Metal Status of Orashi River Along the Engenni Axis, Rivers State of Nigeria

Abstract

Communication in Physical Sciences 2019, 4(2): 74-80

*S. A. Odoemelam, O. S. Edori & M. N. Ogbuagu

Received 14 September 2019/Accepted 07 December 2019/

In order to assess the status of heavy metal contamination in Orashi River, water samples were collected from Orashi River bimonthly at different stations. The samples were analyzed for the concentrations of manganese (Mn), mercury (Hg), cadmium (Cd), lead (Pb), copper (Cu), nickel (Ni), iron (Fe), chromium (Cr) and zinc (Zn) ions using atomic absorption spectrophotometry (AAS). It was observed that the mean concentrations of the metal ions varied in the order: Ni >Fe > Mn > Cu > Zn > Cr > Pb > Cd > Hg. The levels of all the heavy metal ions were lower than WHO and SON standards for drinking water except Ni. There were both spatial and monthly variations in the metal ions concentrations. Calculated contamination factors indicated that the river was at various levels of contamination by the heavy metals except Ni that was observed at pollution level. Pollution index analysis showed slight level of contamination with the heavy metals. Contamination degree and modified contamination degree analysis showed very low degrees of contamination. Findings from this study portend that the Orashi River is at the threshold of contamination if pollution load to the river is not controlled.