Comparative Evaluation of Heavy Metal Concentration in Water and Sediment, Choba Segment of New Calabar River, Port Harcourt, Nigeria

Abstract

The heavy metal concentration in water and sediment, Choba segment of New Calabar River, Port Harcourt was investigated between February and April, 2020. Samples collected from the three locations were analysed in the laboratory for heavy metals using Atomic Absorption Spectrophotometer (AAS) following standard method of APHA. The mean values of heavy metal in water (mg/l) were: Cr (2.29±1.29), Ni (2.32±0.28), Pb (2.46±0.38), Cd (0.04±0.02), Fe (52.18±7.26) while that of sediment were: Cr (7.18±0.43), Ni (5.57±0.29), Pb (8.09±0.39), Cd(0.30±0.15), Fe (123.64±5.17). The heavy metal values showed variations across the stations at P<0.05. The order of concentration of heavy metal in water was: Fe>Pb>Ni>Cr>Cd while that of sediment is Fe>Pb>Cr>Ni > Cd with heavy metal concentration in sediment higher than that of water while Fe and Cd concentrations were highest and lowest in both water and sediment respectively. All the heavy metals in water except Ni exceeded the permissible limits of World Health Organisation (WHO), Federal Environmental Protection Agency (FEPA) while that of sediment were below the permissible limits except Fe. It was concluded from the results that Choba segment of the New Calabar River is under stress since the heavy metals apart from Nickel (Ni) present were above the permissible limit. This implies that the quality of the water is unsafe for use especially for domestic purpose if untreated owing to the on-going anthropogenic activities in the area. Therefore, regulatory standards for discharges from anthropogenic activities should be strictly controlled