Milovan Vuković

Influence of pH on the dissolution kinetics of iron in sulphuric acid solutions

Abstract The effect of pH on the kinetics and mechanism of Armco iron (99.99%) corrosion in deaerated, nitrogen saturated solutions at 21°C was studied. The total concentration of sulphate ions in the solutions tested was 0.5 M . The increase in the pH in the range tested caused a change in the Tafel anodic straight line slope from 28 mV dec −1 (pH 0.6) to 75 mV dec −1 (pH 4.15), without a change in the anodic mechanism. For the anodic dissolution the order of reaction with respect to the OH − ion was found to be − 1. The effect of pH on the corrosion potential and current was also found.

Anodic dissolution of Armco iron in 0.5 M H2SO4 in the presence of adsorbed chloride ions

Abstract Anodic dissolution of Armco iron was studied in 0.5 M H2SO4 solution with and without the addition of NaCl (concentration range 3 × 10−2−1.5 M in Cl−). Comparison with the pure electrolyte showed that Cl− ions at the concentrations tested act as an anodic inhibitor by a blocking mechanism. When Cl− ions are present in concentrations higher than ca. 0.1 M they reverse their action with the reaction order with respect to Cl− ions, nCl− ≈ 1. The observed anodic Tafel slope of ca. 120 mV dec−1 in the presence of chloride ions was explained using the iron dissolution mechanism suggested by Bockris, Dražic and Despic (or BDD mechanism). The accelerating action of Cl− ions at higher concentrations appears to be a consequence of a parallel process in which Cl− ions from the bulk (i.e., not adsorbed) form a complex before the slow step. Adsorbed FeOHads appears as a common intermediate for both parallel routes. The kinetics of adsorption of Cl− on Armco iron electrode was analyzed by different types of adsorption isotherms.

Application of multivariate statistical techniques in the water quality assessment of Danube river, Serbia

Abstract The aim of this article is to evaluate the quality of the Danube River in its course through Serbia as well as to demonstrate the possibilities for using three statistical methods: Principal Component Analysis (PCA), Factor Analysis (FA) and Cluster Analysis (CA) in the surface water quality management. Given that the Danube is an important trans-boundary river, thorough water quality monitoring by sampling at different distances during shorter and longer periods of time is not only ecological, but also a political issue. Monitoring was carried out at monthly intervals from January to December 2011, at 17 sampling sites. The obtained data set was treated by multivariate techniques in order, firstly, to identify the similarities and differences between sampling periods and locations, secondly, to recognize variables that affect the temporal and spatial water quality changes and thirdly, to present the anthropogenic impact on water quality parameters.

MINING-METALLURGICAL SOURCES OF POLLUTION IN EASTERN SERBIA AND ENVIRONMENTAL CONSCIOUSNESS

The ethics of environmental protection is based on the moral responsibility of a man not to endanger his living environment because it is the only way for creating the conditions for a better life quality. Environmental consciousness (EC) is characterized by a high awareness about the environment, especially in urban areas with mining-metallurgical sources of pollution. Raising EC in such environments causes acceptance and ecological and social responsibility. A mining-metallurgical complex plant represents an important source of pollution of urban areas. In that sense, Bor is an interesting urban area having in mind that it represents one of the most important ore and metal production centers in South-East Europe. What defines the EC of Bor inhabitants is derived from the very town and its economy. The research encompasses concrete environmental problems of the mining town Bor and its surroundings. The components of the EC of people living in Bor were analyzed according to the awareness, knowledge and attitude method, having in mind the extent to which the environment has been polluted in this area. It has been concluded that the perception of people living in Bor about the state of the environment depends on numerous factors – first, whether the employee works for the RTB Bor Company or not.

The assessment and prediction of temporal variations in surface water quality—a case study

In order to optimize the processes of sampling, monitoring, and management, the initial aim of this paper was to develop a model for the definition and prediction of temporal changes of water quality. In the case of the Morava River Basin (Serbia), the patterns of temporal changes have been recognized by applying different multivariate statistical techniques. The results of the conducted cluster analysis are the indicators of the existence of the three monitoring periods: the low-water, transitional, and high-water periods, which is in accordance with changes in the water flow in the analyzed river basin. A possibility of reducing the initial data set and recognizing the main pollution sources was examined by carrying out the principal component/factor analysis. The results indicate that the natural factor has a dominant influence in temporal groups. In order to recognize the discriminatory water quality parameters, a discriminant analysis (DA) was carried out. Conducting the DA enabled a significant reduction in the data set by the extraction of two parameters (the water temperature and electrical conductivity). Furthermore, the artificial neural network technique was used for testing the possibility of predicting changes in the values of the discriminant factors in the monitoring periods. The reliability of this method for the prediction of temporal variations of both extracted parameters within all temporal clusters has been proven.

Tourist attractiveness of Felix Romuliana archaeological site

Archaeological site Felix Romuliana is located in Eastern Serbia, on the 10th kilometer of Boljevac - Zajecar road. It represents the remains of the Roman emperor Gaius Valerius Maximian Gallery’s palace. The value and importance of this unique monument, which dates from the late Roman period, are shown by the fact that in 2007. it was included in the UNESCO list of world cultural heritage. This paper introduces touristic - geographic location of Felix Romuliana, its artistic value, history and progress of archeological research as well as protection measures and site management system. The second part consist the tourist valorization results, made by Hilari du Cros model. Aim of the article is to determine the manner in which it is possible to make a presentation of cultural and historic values of the potential tourists (both domestic and foreign) and to point out the weaknesses and the opportunities in the tourist valorization. Finally, it can be concluded that the strategy for tourism development in this area should be based on the promotion of cultural tourism, which would be the holder of the Gamzigrad archeological complex.