Chemistry Journal of Moldova

Downloads: 74

DOI: dx.doi.org/10.19261/cjm.2014.09(2).03

Graphical Abstract: On the basis of currently revised thermodynamic data for Cr(III) and Cr(VI) hydrolysis and photolytic equilibria in addition to original thermodynamic and graphical approach, used in this paper, the repartition of their soluble and insoluble chemical species has been investigated. By means of the diagrams “ΔG – pH”, the areas of thermodynamic stability of chromium(III) hydroxide have been established for a number of the analytical concentration of Cr(III) in heterogeneous mixtures. The obtained calculated results correlate well with existing experimental data.


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DOI: dx.doi.org/10.19261/cjm.2014.09(2).04

Graphical Abstract: Old icons, especially those involved in liturgical rituals are affected in time by external agents factors (temperature, humidity, light, pollution, microbiological attack, abrasion etc.), resulting changes of the appearance. Based on the literature in the field, a series of alcoholic solutions of different concentrations were made, as such or basified, which were compared with ecologic synergic systems based on organic uncolored vegetable juices and decoctions from dried plants. The cleaning effectiveness was done by visual analysis and CIE L * a * b * reflection colorimetry, this technique permitting to determine by color deviations the critical point where the patina and polychromy.




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DOI: dx.doi.org/10.19261/cjm.2014.09(2).05

Graphical Abstract: The mathematical model of electrochemical processes distribution within the three-dimensional flow-through electrode for the system Fe(III)/Fe(II)/Fe is described in this paper, considering also the electrochemical reactions of hydrogen and molecular oxygen reduction. The results of calculations and experimental studies of iron electro-reduction are given, the analysis of the numerical modeling is provided.



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DOI: dx.doi.org/10.19261/cjm.2014.09(2).06

Graphical Abstract: The main regularities of the electroactive components distribution, polarization and local current density within the depth of the three-dimensional flow-through electrode have been studied using the calculation method, in dependence on the overall current density, electrode thickness and degree of its compression, solution flow velocity through the electrode, initial concentration of Fe(III) ions in the solution and electrodes brand.




Downloads: 31

DOI: dx.doi.org/10.19261/cjm.2014.09(2).07

Graphical Abstract: Kajaran town is situated in the south-east of the Republic of Armenia in Syunik Marz. Developed mining and smelting industries can be observed in this area. Six the most risky sites in this area and an unpolluted site as a control were selected for the study. The content of metals was determined by means of ELAN 9000 ICP-MS System. Study results revealed the increase up to 17 times in contents of following metals: Co, Ni, Cu, Zn, Cr, Sr, Mo, Cd, Pb, As. Experiments have led us to the assumption that pollution of soils with heavy metals in the studied territory is conditioned by human activities, particularly by mining and smelting industry.


Downloads: 45

DOI: dx.doi.org/10.19261/cjm.2014.09(2).08

Graphical Abstract: Processes of removal of divalent ions of iron and manganese and hydrogen sulfide from groundwater at various pH values and temperature were studied. Obtained results have been used in order to elaborate a process of groundwater purification from the mentioned pollutants. The use of elaborated process for natural water leads to the decrease of the content of iron, manganese and hydrogen sulfide below the maximum allowable concentrations.


Downloads: 47

DOI: dx.doi.org/10.19261/cjm.2014.09(1).03

Graphical Abstract: Technologies for active carbons obtaining from vegetable byproducts such as straw, nut shells, fruit stones, sawdust, hydrolysis products of corn cobs and sunflower husks have been developed. The physico-chemical characteristics, structural parameters and sorption characteristics of obtained active carbons were determined. The ability of carbonaceous adsorbents for detoxification of soil against pesticides, purification of surface waters and for removal of organic pollutants from wastewaters has been evaluated. The obtained results reveal the effectiveness of their use in a number of environmental technologies.


Downloads: 77

DOI: dx.doi.org/10.19261/cjm.2014.09(1).04

Graphical Abstract: In the article the results of comparative analysis of the composition of the Eurasian hydromineral resources and the assessment of their impact on the physiological condition of a human organism according to biochemical studies of venous blood are presented. Processing of initial data on the composition and properties of mineral waters chloride-hydrocarbonate, sulphate- hydrocarbonate and chloride-sulphate types and venous blood are made using the method of mathematical modeling, developed by the authors of this article. It is shown that in the balneological impact of hydromineral resources on the body in the blood increases the hemoglobin and oxygen, decreases glucose, and acid-base pH shifted to high alkalinity.


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DOI: dx.doi.org/10.19261/cjm.2014.09(1).05

Graphical Abstract: The study presents data concerning the water pollution status of Siret hydrographical basin (i.e. surface and ground waters, lakes) in Suceava County area (different controlling/monitoring sections) due to agricultural productive activities, especially regarding some quality indicators (nitrogen-based nutrient concentrations) evaluated for 2008. These data are recommending the necessity of continuous monitoring of water quality in the Siret River hydrographical basin, in all existing control sections, for identification of any pollution episodes, non-reported by polluters to the local environmental regulators.


Downloads: 43