Hamid Reza Pakzad; Mehrdad Pasandi; Ardeshir Romiani; Mahdi Kamal
Volume 12, Issue 2 , July 2014
Abstract
The Anzali wetland is highly important for the particular ecologic, economic and social conditions. Several rivers discharge to Anzali wetland after passing through surrounding forests, towns and villages. Sampling of the sediments of Anzali wetland was carried out at 22 sampling points located in the ...
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The Anzali wetland is highly important for the particular ecologic, economic and social conditions. Several rivers discharge to Anzali wetland after passing through surrounding forests, towns and villages. Sampling of the sediments of Anzali wetland was carried out at 22 sampling points located in the inflowing rivers and the canals connecting the wetland to the Caspian Sea in order to determine the heavy metals concentrations and also physicochemical properties influencing concentration of these elements. The major clay minerals of these sediments are montmorillonite, chlorite and kaolinite in their order of abundances. The result showed that the concentration of Cr, Cu and Ni increased in the samples with higher amount of clay and the Zn concentration increases in the samples containing montmorillonite and illite. Increases of the Cr and Cu concentrations and decreases in the Ni concentration conform to increase in the amount of TOC. The Ni concentration was higher in the samples with higher Fe and Mn concentration. The amount of calcium carbonate is positively correlated with the Sr concentration. According to the enrichment factor, Cu and Zn showed average enrichment in just one sample. Ni, Sr and Cr were depleted in the fine-gained sediments of Anzali wetland.
Hajar Rahimi,; Hamid Reza Pakzad; Mehrdad Pasandi
Volume 9, Issue 4 , July 2012
Abstract
The fine grained sediments of Gavkhoni Playa Lake have the potential for concentrations of heavy metals due to climatic conditions, petrology and the presence of lead and zinc ores in the drainage basin and the passage of Zayandehrud River through industrial and agricultural regions. In this research, ...
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The fine grained sediments of Gavkhoni Playa Lake have the potential for concentrations of heavy metals due to climatic conditions, petrology and the presence of lead and zinc ores in the drainage basin and the passage of Zayandehrud River through industrial and agricultural regions. In this research, muddy sediments from the delta and playa of Gavkhuni Playa Lake were sampled to determine the levels of concentration of heavy metals and the geochemical/sedimentological parameters. Calcium carbonate, pH and organic matter increase while clay and Eh decrease from North to South of the playa. Clay minerals of muddy sediments in their order of frequency include, respectively, illite, chlorite, kaolinite and montmorillonite and the amount of these minerals does not vary from the delta to the south of the playa.Average concentrations of the heavy metals in ppm in order of abundance are: Zn (46.96), Pb (39.25), Co (8.14) and Cd (3.53). Cd and Pb concentrations are greater than normal while the Co and Zn concentrations are almost equal to the usual concentrations of these elements in shale. The Geoaccumulation index shows that the sediments are highly polluted by Cd, slightly to unpolluted polluted by Pb and not polluted to the other heavy metals. Exchangeable cation contents are much lower than the total concentrations. Organic matters play a more important role in the exchangeable concentration of the heavy metals relative to the type and content of clay minerals and their increase has augmented the exchangeable concentrations.
