Evaluation of anthropogenic impacts on soil and regolith materials based on BCR sequential extraction analysis

This study was conducted in Assaluyeh region, southwest of Iran to show utilization and efficiency of sequential extraction analysis in environmental impact studies using soil and related regolith materials as sample media. In order to investigate distribution of heavy metals, optimized BCR [Community Bureau of Reference] sequential extraction analysis method was used. In this case eight representative samples which state all types of different regolith materials in the area were investigated. Total concentration and chemical partitioning of a number of elements [Pb, Cu, Zn, Cr, Mn and Fe] were studied to cover all spectral from typical anthropogenic elements, lead and copper, elements of assumed mixed origin, chromium and zinc, to mostly lithogenic elements, iron and manganese. Results stated that the concentrations of each chemical phase extracted from samples are below the total concentration of each element.The results could be used to establish best media indicators for environmental studies with dependence on type of elements determined in regolith material. Using sequential extraction analysis, the association of particular elements with geochemical phases in soils and related materials was investigated as well as the importance of particular phases in the scavenging of heavy metals. Results showed that the organic and sulphide phase was less important in scavenging mechanism -in spite of industrial and petrochemical activities in the study area- than exchangeable and carbonate fraction, which showed to be most important phase with respect to metal scavenging capacity

Evaluation of salt effects on some thermodynamic properties of Urmia Lake water

In this study some thermodynamic parameters including freezing point, boiling point and the vapor pressure of Urmia Lake salt water were investigated as some important environmentally monitored physicochemical properties of Urmia Lake. In this regard salt concentration is chiefly responsible for the modification of the thermodynamic properties of Urmia Lake water which affects its overall environmental and ecological characteristics. On the other hand, the Urmia Lake is now supposed to be the most convenient place for many rare aquatic species and therefore interpreted to be unique from the viewpoint of qualitative characteristics. For the goals of this study water sampling and analysis where performed in two wet and dry periods of the lake in order to represent the extremes of the lake's environmental variability. Prevailing chemical ions in the water body were determined and used for the estimation of the relative thermodynamic coefficients of salt water for the acquisition of the freezing point, boiling point and the vapor pressure of the Urmia Lake water. Interpolated calibration curves were plotted for the changes in the studied parameters versus a variety of salt concentrations indicating a linear relationship between the investigated parameters and the prevailing salt concentration of the Urmia Lake. The calibration curves were then formulated to simplify the estimation of the thermodynamic parameters of the Urmia Lake for any salinity conditions. Real sample analysis also showed a very good agreement between the estimated and observed values