Determination of heavy metals bonding in various sedimentary phases in Behshahr River and Abbas Abad dam

In this study, the sediments from Abbas Abad dam and two rivers entering into it and a tributary river are chemically analyzed to determine the concentration of heavy metals along with iron and calcium and their origin. The pollution intensity of river was also computed.
Sampling was carried out at 6 stations along the river in September 2013. In the first step, the bulk concentrations of Iron, Calcium, Magnesium, Zinc, Copper, Nickel, and Cadmium were determined. Subsequently, a 5 steps chemical partitioning technique was used to identify the association of metals with different sedimentary phases.
Findings: Majority of the studied metals have lithogenic sources while a significant portion of Cd is originated from anthropogenic sources. The result of chemical partitioning studies is well in accordance with the pollution intensity computations. Cluster analysis dendrogram reveals that the source for Zinc, Copper, and Nickel is oil, for Iron might be lithogenous, for calcium is biogenetic and for Cadmium and magnesium is unknown. The pollution intensity has been presented by various indices such as EF, Ipoll and Igeo. The two indices, namely IPOll and Igeo, are indicative of a non-polluted environment for all elements except for Cadmium with low pollution. The results of these two indices are in accordance with chemical partitioning studies. The results of the present study show that application of EF in determination of pollution intensity is limited.
Considering the total concentration and its comparison with other indices, the study area is not polluted and only an insignificant contamination with Cd is noticed.