Origin and chemical partitioning of heavy metals in riverbed sediments

In the present investigation, bulk and chemical partitioning of elements in the Shefa-Rud riverbed sediments are studies. Higher concentrations of elemental concentrations have been observed in estuarine zone when compared with riverine sediments [except for Al, Fe, Pb and Mn]. Manganese is mobilized under anoxic conditions prevailing in the Caspian Sea. Lithogenous materials are greatly diluted in the estuarine zone by various pollutants present in the Caspian Sea. Organic metallic bonds are not significantly present in the area of study. Geological units of the area of study have resulted in the lower concentrations of elemental concentrations of riverbed sediments when compared with published values for mean crust and world sediments ones. Though, cluster analysis has clearly shown the importance of alumina-silicates in controlling the distribution of Fe and Mn in riverbed sediments but it could not depict controlling mechanism for other studied elements. Geochemical Index [Igeo] and Enrichment Factor [EF] values are indicative of a clean environment throughout the river course. These values are in a well agreement with results of chemical partitioning data. Quantification of EF values is not logically possible and therefore Igeo values can be used more effectively

Environmental geochemistry of heavy metals in a sediment core of Bushehr, Persian gulf

In present study, the geochemistry of a sediment core from the Persian Gulf is investigated. The sources of trace elements [Cu, Zn, Pb, Ni, Cr, Mn] have been investigated by the method of cluster analysis as well as chemical partitioning techniques. Cluster analysis shows that Pb, Cu, Cr and Zn are originated from oil pollution sources taking into account Zn as an oil pollution indicator. Higher concentrations of Mn at depth of 7cm clearly shows the movement of Mn from the lower layer of the sediment core. Considerable amount of Mn, Pb and Cu are found in lithogenous portion The results of partition studies has revealed the percentile of anthropogenic portion of metals as: Mn [46%]> pb [40%]> Cu [18%]> Zn [12.8%]> Fe [2.4%]> Cr and Ni [0.03] Finally, the concentration of studied metals are compared with those of mean crust and mean world sediments. Though concentrations of a few metals are higher than mean crust and men world sediments but Cr in-spite of its higher concentration is mainly derived from natural resources. The results indicate that, a system that combines the two mentioned processes not only shortens stabilization time, but also improves the products quality. Combining the two systems resulted in a product that was more stable and homogenous; the product could meet the pathogen reduction requirements