Evaluation of heavy metals status in water from Okamini Stream in Obio/Akpor, Rivers State, Nigeria.

Abstract

The contamination/pollution status of surficial water is an issue of global concern. Water samples collected from Okamini Mini Stream were subjected to heavy metals investigation using an atomic absorption spectrophotometer. The result obtained gave mean metals values in mg/L as; Mn (0.382±0.103), Pb (0.829±0.502), Cu (0.815±0.398), Cd (0.022±0.015), Ni (1.590±0.651), Cr (1.32±1.369), Fe (1.457±0.876), Zn (1.353±1.234), As (0.060±0.093) and Co (0.183±0.147). The values obtained from the stream indicated that the levels of the examined metals except Cu and Zn were above the WHO requirement for drinking water. Contamination factor analysis specified that the amount of the metals in surficial water on an individual basis are at variable degrees of pollution except Cu and Zn which are present at contamination levels. Pollution load assessment showed that the water from all examined points was slightly polluted by heavy metals. The contamination degree valuation of the heavy metals revealed the values to be > 32 in all the stations, which showed a very high contamination degree. Modified degree of contamination values were found to fall within the range of 9.336-37.974 (very high degree of contamination - ultra-high degree of contamination). The values of the metals indicated a water system greatly interfered with anthropogenic activities and made the water unhealthy for home purposes.