RESUMO
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
RESUMO
Development of higher welfare could not be realized unless by energy consumption and other natural resources. Growth of industrial complexes has shown an unprecedented trend during recent years. Many of these towns have no treatment systems for the industrial wastes leachates. Besides, the chemical composition of wastes in such complexes varies considerably due to the different kinds of industries. It is endeavored in the present work to study the natural potential of soil to treat leachate of such industrial wastes. For this purpose, the Aliabad industrial complex in Tehran-Garmsar road was selected as the study area. The potential of adsorption of elements such as nickel, copper, cadmium, zinc, chromium, lead and manganese was investigated. The results indicated that the soil potential to adsorb heavy metals [except for manganese] was very high [95%] in the adsorption of heavy metals [except for manganese]. Further, chemical partitioning studies revealed that heavy metals are associated with various soil phases such as loosely bonded ions, sulfide and organics to various extents. Among the mentioned soil phases, one can deduce that major portion of metal contaminants is absorbed as loosely bonded ions. Organic bond and sulfide bond are in the 2 [nd] and 3 [rd] positions of metal contaminants adsorption, respectively. The results of the present study apparently showed that soil column had ample capacity to adsorb metal contaminants. Thus, determination of soil potential in adsorption of heavy metals during site selection is as important criteria
Assuntos
Metais Pesados , Solo , Adsorção , IndústriasRESUMO
In this study, spatial and seasonal variations of water quality in Haraz River Basin were evaluated using multivariate statistical techniques, such as cluster analysis, principal component analysis and factor analysis. Water quality data collected from 8 sampling stations in river during 4 seasons [Summer and Autumn of 2007, Winter and Spring of 2008] were analyzed for 10 parameters [dissolved oxygen, Fecal Coliform, pH, water temperature, biochemical oxygen demand, nitrate, total phosphate, turbidity, total solid and discharge]. Cluster analysis grouped eight sampling stations into three clusters of similar water quality features and thereupon the whole river basin may be categorized into three zones, i.e. low, moderate and high pollution. The principle component analysis/factor analysis assisted to extract and recognize the factors or origins responsible for water quality variations in four seasons of the year. The natural parameters [temperature and discharge], the inorganic parameter [total solid] and the organic nutrients [nitrate] were the most significant parameters contributing to water quality variations for all seasons. Result of principal component analysis and factor analysis evinced that, a parameter that can be significant in contribution to water quality variations in river for one season, may less or not be significant for another one