Heavy Metal Concentrations in Mangrove Sediments and R. racemosa in Niger Delta, Nigeria

This study assessed the concentration of As, Pb, Zn, Cu, Ni, Cr, V, Sr, Y, Nb, Zr, Cl, TS, TiO2, MnO, CaO and P2O5 in the mangrove sediment and R. racemosa samples from Choba, Ogbogoro and Isaka in Niger Delta, Nigeria. A total of 6 sediment and 9 R. racemosa samples were collected using the simple random sampling. Two core sediment samples of 10 cm depth and three R. racemosa leave, stem and root samples were collected from each of the sampled locations. Both the sediment and R. racemosa samples were oven dried, powdered, made into briquettes and analyzed using XRF. The results showed contrasting heavy metal concentrations in the sediments and R. racemosa. As, Pb, Cu, Ni, Y, Nb and Zr had higher concentrations in the sediments while the concentrations of Zn, Sr, Cl, TS, MnO, CaO and P2O5 were more in R. racemosa tissue. However, Cr, V and TiO2 which had relatively high concentrations in the sediments were not detected in R. racemosa. Graphical analyses revealed a correlation between concentrations in sediment and R. racemosa as well as a similar pattern of heavy metal concentrations in the R. racemosa leaves, stems and roots in Choba, Ogbogoro and Isaka. But variations were found in the leaf/stem and leaf/root upward transport relationship. Most heavy metals were found to concentrate in R. racemosa roots while the least concentrations were found in the leaves.