Land use effects on heavy metal pollution of river sediments in Guilan, southwest of the Caspian sea

Studies have showed the River Siahroud is the main contributor to the present pollution of Anzali Wetland in Guilan. Therefore, this study was initiated to evaluate the spatial distribution of metals pollution on the River Siahroud sediments in Guilan. Surfacial river sediment samples along this river were taken during five consecutive seasons at eight sampling stations and analyzed for availability of Fe, Mn, Pb, Zn, Cu, Cr, Cd metals. Canonical correlation demonstrated that the total organic carbon (TOC) was of great importance in co-precipitation of Zn while Cu and Pb were mainly related to hydrous iron oxides. Also, in the interest of pollutant finger printing, factor analysis showed that extractable Zn, Cu, Fe, Cd and Mn were attributed to the present agricultural fields while industrial site of Rasht City was the major contributing factor for the extended levels of Cr in the study area. Moreover, Pb level was mainly relevant to urban land use in Rasht. Cluster analysis demonstrated that there was a rising metal pollution level in the River Siahroud from upstream to downstream suggesting that Anzali Wetland pollution could be highly related to loading of heavy metals by the River Siahroud sediment

Land use effects on heavy metal pollution of river sediments in Guilan, southwest of the Caspian sea

Studies have showed the River Siahroud is the main contributor to the present pollution of Anzali Wetland in Guilan. Therefore, this study was initiated to evaluate the spatial distribution of metals pollution on the River Siahroud sediments in Guilan.Surfacial river sediment samples along this river were taken during five consecutive seasons at eight sampling stations and analyzed for availability of Fe, Mn, Pb, Zn, Cu, Cr, Cd metals. Canonical correlation demonstrated that the total organic carbon (TOC) was of great importance in co-precipitation of Zn while Cu and Pb were mainly related to hydrous iron oxides. Also, in the interest of pollutant finger printing, factor analysis showed that extractable Zn, Cu, Fe, Cd and Mn were attributed to the present agricultural fields while industrial site of Rasht City was the major contributing factor for the extended levels of Cr in the study area. Moreover, Pb level was mainly relevant to urban landuse in Rasht. Cluster analysis demonstrated that there was a rising metal pollution level in the River Siahroud from upstream to downstream suggesting that Anzali Wetland pollution could be highly related to loading of heavy metals by the River Siahroud sediment

Transport of Polycyclic Aromatic Hydrocarbons in a Calcareous Wetland Soil

Knowledge of transport and degradation of polycyclic aromatic hydrocarbons (PAHs) is important in assessing PAH contamination of soils and water resources. The transport of naphthalene, anthracene, pyrene and phenanthrene was determined in a contaminated calcareous soil obtained from the Shadegan wetland (Khozestan, Iran) considering a column study in laboratory conditions. The PAHs were added to the top 5 cm of soils at 75 and 150 mg kg-1 and leachates were collected for 10 pore volumes. PAH concentrations in the leachate fractions and soils (0-5, 5-10, 10-15 and 15-20 cm depths) were determined using high pressure liquid chromatography. Results showed that naphthalene had the most mobility among the PAHs, and differences among the mobility of selected PAHs were related to their water solubility and structure. Mass balance demonstrated that among the selected PAHs, anthracene and naphthalene were the most and the least recalcitrant compounds, respectively. Hence, naphthalene could have the greatest potential to contaminate surface and ground waters which should be considered apparently