Determination of Heavy Metal Contamination in Sediments of the Anambra River, Nigeria

This work investigated six heavy metals (Pb, Hg, Cd, Mn, Fe and As) in sediment samples of the Anambra River collected from five sampling points at 1km from each other. The Anambra River cuts across several towns and flows into River Niger in Anambra State Nigeria. A total of forty sediment samples were used for the study. The samples were collected from November 2017 to Feb 2018 (dry season sampling) then from May 2018 to August 2018 (wet season sampling). Metal ion concentration in the sediments was determined using Atomic Absorption Spectrophotometer (AAS). Experimental results showed the concentration of metals in the order of Fe > Mn > As > Cd > Hg > Pb (Dry season) and Fe > Mn > As >Hg > Pb >Cd (wet season). In both seasons iron, manganese and arsenic recorded higher values than other metals. Results from Contamination Factor (CF) calculation showed that all the metals analyzed (except for arsenic) exert low contamination effect on the sediment samples in both seasons. Arsenic exerts considerable contamination in dry season. This study provided information on heavy metal concentration in sediment, magnitude of contamination, likely ecological risk to man and other living organisms within the Anambra River catchment area.