نشریه زمین شناسی محیط زیست
پیاپی 53 (زمستان 1399)

The special importance of the Karaj River and Dam in the establishment of sustainable security of water supply in Tehran and maintaining the ecological stability of the aquatic environment and human activities related to water play a prominent and vital role. The aim of this study was to identify sources of pollutants. Quality of surface water resources for 8 water quality parameters (sulfate, chlorine, calcium, magnesium, sodium, potassium, total solute, electrical conductivity and sodium uptake ratio) in 10 Karaj-Amir dam dams It was great. In this study, the effect of changes in hydrological parameters on pollutant sources as well as the spatial origin of these pollutants and the appropriateness of watershed management measures during the 40-year period from 1347 to 1398 were investigated using Convik correlation analysis and principal component analysis. The results showed that the application of factor analysis in evaluating surface water quality parameters is one of the important cases for source and elimination of information noise. Focal variables 1 and 2 with correlation coefficients of 0.98 and 0.81 have potential ability especially for changes in environmental variables such as rainfall (H) and The volume of annual sediments (W) has a direct effect on the three elements of water quality, namely calcium, total salts and total hydrogen ratio, respectively, and they establish a direct relationship. The results showed that the share of incoming pollution load from the tributaries of the Karaj River due to the uses located in them in the pollution of the dam reservoir is more than the main tributary of the river and its uses. In particular, the sub-basins of Velayatrud, Shahrestanak and Sira have a total of more than one third of the share of pollution entering the reservoir.

In the event of an earthquake environmental hazard, reinforced concrete buildings in Tehran, in addition to destroying and inflicting extensive human and financial losses, will lead to the production of construction debris and mass debris. In this study, the reliability analysis in 110 concrete buildings running in area one of Tehran with the assumption of variable compressive strength of concrete and yield strength of rebar has been investigated. That is, it has compared the flexural frame and the flexural frame with the shear wall. And this is slightly higher in shear walls. Also, in all tested rebar’s (environmentally friendly), the average yield strength was higher than the nominal strength. Regarding seismic performance, shear wall structure has less general and relative displacement than flexural frame structure. The results of reliability analysis showed that the use of shear wall system instead of bending frame can reduce damage to non-structural components and consequently reduce the production of construction debris and preserve the environment.

Acidic dissolution of chalcopyrite in the presence of ferric ion is a scientific challenge that is the subject of research by many researchers. The role of pyrite has also been studied as catalyst and enhancer of chalcopyrite leaching. Previous studies have shown the chalcopyrite electrochemical leaching in the presence of oxidants, and oxidation-reduction reactions depend on reaction environmental conditions. In this paper, in addition to electrochemical techniques (cyclic voltammetry and chronoamprometry), mathematical calculations and thermodynamic equations have been used to investigate the effect of ferric ion and pyrite on oxidation-reduction reactions of chalcopyrite. First, the oxidation-reduction reactions of chalcopyrite surface by cyclic voltammetry in acidic medium and then the effect of ferric ion addition on these reactions have been investigated. Then effect of pyrite presence along with the ferric ion (pyrite / ferric ion) is studied by the above method. The results of cyclic voltammetry method showed that ferric ion and pyrite increased the anodic and cathodic peak intensities and had a positive effect on chalcopyrite surface reactions. Also results of chronoamprometry and thermodynamic studies showed increase of free energy of chalcopyrite oxidation reaction in the presence of pyrite which was -22.45 kJ/mol.