Effects of Sediment Characteristics on the Accumulation and Transfer Rate of Heavy Metals in Mangrove Trees (Case Study: Nayband Bay and Qeshm Island )

Abstract

In this paper, the accumulation of heavy metals of Nickel (Ni) and Vanadium (V) was measured in habitat sediments, mangrove roots and leaves (Avicennia marina). Besides, the transfer of Ni and V from the sediment to root and to the leaves in Nayband Bay and Qeshm Island were studied. The samples were gathered by Systematic-random Sampling using selective transects at 16 stations at the end of mangrove cover in both sides of land and sea in two habitats with three replicates of sediment, root and leave samples. The bed characteristics including sediment texture, pH, EC and organic matters were determined. The concentration of Ni and V was measured by atomic absorption spectroscopy (AAS), and then the metal transfer factor from sediment to root and root to leave was calculated. The correlation of the metal transfer factor and sediment characteristics was analyzed using the SPSS software (version 19). In the sample of sediments, roots and leaves respectively, the most concentrations of nickel and vanadium were measured. About transfer of Ni and V, transfer rate from sediment to root was much higher than from root to leave. In addition, the highest transfer factor from sediment to root and from root to leave was obtained for V in Qeshm habitat (0.502) and for Ni (0.749) in Nayband Bay. It seems that the difference between sediment textures in the two habitats and widespread oil and gas activities in Nayband Bay might be the notable reasons for the difference in transfer rates in two the habitats. Therefore, we conclude that the finer texture of Qeshm habitat increased transfer of V from sediment to root, and the coarser texture associated with increasing air pollution in Nayband Bay caused more Ni to accumulate in the leaves