Impact Assessment of Anthropogenic Activities on Heavy Metals in Water and Sediment in Eniong River, Nigeria

Abstract

This research was carried out to assess the impacts of anthropogenic activities on heavy metal concentrations in water and sediments in Eniong River, Nigeria. The study was carried out for a period of twelve months, covering both the wet and dry seasons. Water and sediment samples were analyzed to determine the concentration of selected heavy metals such as Cd, Cu, Cr Fe, Pb, and Zn. The analysis was done using an atomic absorption spectrophotometer. The result revealed variation in the concentration of all heavy metals across the sampling locations. The concentrations ranged from 0.00 – 0.15 mg/L and 0.01- 11.75mg/kg for water and sediment samples, respectively. Concentrations of some metals were higher in due to tremendous anthropogenic activities. Comparatively, concentrations were higher in sediment samples 11.75mg/kg than in water samples 0.15 mg/L, which could be attributed to desorption of the metals from water onto the sediment beneath the water. The results also revealed that some metals, such as Copper (0.15 mg/L) and Iron (0.15 mg/L) were higher in water than in sediment. Generally, highest concentration of 11.75mg/kg for chromium was recorded in sediment samples compared to other heavy metals. Concentration of the metals followed the pattern shown: Cu > Fe > Cr > Zn > Pb > Cd for water samples and Cr > Cu > Fe > Zn > Pb > Cd for sediment. It could be concluded that the highest concentration of the metals in water and sediment samples were 0.15mg/l and 0.15mg/kg respectively and were recorded in the location of tremendous anthropogenic activities, reflecting a corresponding higher impact on the metals. This suggests the need for routine monitoring to prevent escalation.