Seasonal Dynamics of Heavy Metal Pollution of Niger Delta River Sediment Receiving Industrial Effluents

The heavy metal changes of Okpoka-Woji River serving as a sink of effluent of industries located in its vicinity within the Trans Amadi Industrial area were monitored over rainy and dry season months in order to follow the seasonal dynamics engendered by the dumping. Sediment samples from six sampling stations located along the river were collected for the determination of heavy metals. The mean values for the heavy metals were as follows: lead ranged from 17 67.2 mg/kg and 22.3-67.8 mg/kg; iron 7,995.5 17024.2 mg/kg and 6949.3 21,403 mg/kg; chromium 0.8-2.3 mg/kg and 16-3.4 mg/kg; Zinc 3195.1 4455.5 mg/kg and 1713.4-3417.3 mg/kg; manganese 22.5 100.6 mg/kg and 20.8 121.7 mg/kg; nickel 2.4 9.2 mg/kg and 2.0-6.9 mg/kg; vanadium 25.6 42.2 mg/kg and 26.150.2 mg/kg; copper 19.5 46.9 mg/kg and 36.7 67.5 mg/kg; cadmium 0.3 1.6 mg/kg and 0.8 1.6 mg/kg; barium 21.1 77.6 mg/kg and 22.6 34.0 mg/kg respectively for the rainy and dry season months. These results showed that seasonal changes as well as industrial effluent discharges influenced the heavy metal values of the river.