Mjerenje koncentracije aktivnosti torona i radona pomoću detektora nuklearnih tragova

Radon activity concentrations in the air were measured with LR-115 nuclear track detectors at three locations in Osijek. The respective equilibrium factors and the effec tive dose equivalents were determined. Indoor concentrations were from 9.8 to 38.2 Bq m-3 and relative errors of the track etching method were near 19 per cent. The indoor alpha potential energy of the radon and thoron progenies was measured with an ISD detector. Independent measurements, performed with a Radhome semiconductor detector, showed that the indoor thoron concentration was nearly 20 per cent of the radon one.Pomoću detektora nuklearnih tragova LR-115 izmjerene su koncentracije aktivnosti radona u zraku na tri lokacije u Osijeku i određene su vrijednosti ravnotežnoga faktora te efektivni dozni ekvivalenti. Radonske koncentracije u kućama bile su od 9,8 do 58,2 Bq m-3, relativna pogreška metode jetkanja bila je blizu 19%. Potencijalna alfa energija za radonove i toronove potomke izmjerena je pomoću detektora ISD. Nezavisno izvedena mjerenja s poluvodičkim detektorom Radhome pokazala su da koncentracije torona u zraku iznose blizu 20% koncentracije radona

Seasonal variations of microbiological parameters of water quality of the Velika Morava river Serbia

In this study, we investigated the level of sanitary pollution and organic contamination of the Velika Morava River, the largest river in central Serbia. Samples of water for microbiological analysis were collected at 5 sites, monthly, from April 2010 to February 2011. Sanitary analysis, i.e. enumeration of total and fecal coliforms and intestinal enterococci, indicated moderate to critical fecal contamination, while organic load assessment (oligotroph to heterotroph ratio, index of phosphatase activity) revealed the category of moderately polluted water. We also investigated seasonal variations of these groups of bacteria and the factors that could contribute to these differences. Our results showed that the micro- biological quality of the water in the Velika Morava River during different seasons is affected by numerous factors such as unequal loading of wastewaters, solar irradiation, and relations of flow/dilution and rainfall/runoff. [Acknowledgments. This study was financially supported by the Ministry of Education and Science of the Republic of Serbia: projects No 173025, No 177045 and No 043002.

Comparison of comet assay parameters for estimation of genotoxicity by sum of ranking differences

Genotoxic potential of waters in six rivers and reservoirs from Serbia was monitored in different tissues of chub (Squalius cephalus L. 1758) with the alkaline comet assay. The comet assay, or a single cell gel electrophoresis, has a wide application as a simple and sensitive method for evaluating DNA damage in fish exposed to various xenobiotics in the aquatic environment. Three types of cells, erythrocytes, gills and liver cells were used for assessing of DNA damage. Images of randomly selected cells were analyzed with a fluorescence microscope Leica and image analysis by software (Comet Assay IV Image analysis system, PI, UK). Three parameters (tail length - l, tail intensity - i and Olive tail moment – m) were analyzed on 1750 nuclei per cell type. The procedure for sum of ranking differences (SRD) was implemented to compare different types of cells and different parameters for estimation of DNA damage. Regarding our nine different estimations of genotoxicity: tail length, intensity and moment in erythrocytes (rel, rei, rem), liver cells (rll, rli, rlm) and gill cells (rgl, rgi, rgm) SRD procedure has shown that the Olive tail moment and tail intensity are (almost) equally good parameters; the SRD value was lower for the tail moment and tail intensity than for tail length in case of all types of cells. The least reliable parameter was rel; close to the borderline case were rei, rll, and rgl (~5% probability of random ranking)

The anthropogenic impact on water quality of the river Danube in Serbia: Microbiological analysis and genotoxicity monitoring

The aim of this work was to examine the impact of urban wastewaters on the water quality of the Danube River in Serbia. Samples of water and sediments for microbiological analysis and genotoxicity monitoring were collected from 6 sites during spring and/or autumn 2010. Sanitary analysis, i.e. enumeration of total and fecal coliforms and intestinal enterococci, indicated moderate to critical fecal contamination, while organic load assessment (oligotroph to heterotroph ratio, index of phosphatase activity) revealed the category of moderately polluted water. Mercury-resistant bacteria were detected in all water samples, with high numbers at locations positioned downstream of Belgrade. There was no correlation of the microbiological parameters of the sediment and water samples. Genotoxicity monitoring, performed by the comet assay on hemocytes of mussels Sinanodonta woodiana, indicated a significant increase of DNA damage in mussels collected from the studied sites compared with the control group.Projekat ministarstva br. 173025 i br. 4300

Bioremediation Kinetics of Pharmaceutical Industrial Effluent

U radu je istražena bioremedijacija otpadne vode iz proizvodnje farmaceutika tvrtke Pliva Hrvatska d.o.o. pomoću aktivnog mulja i bioaugmentiranog aktivnog mulja s izoliranom mješovitom bakterijskom kulturom. Pokusi su provedeni šaržno u submerznim uvjetima s početnom koncentracijom organske tvari u otpadnoj vodi γS0 = 5,01 g dm−3, izraženoj kao vrijdnost KPK te s različitim početnim koncentracijama biomase, γX0, u rasponu od 1,16 do 3,54 g dm−3. Endo-Haldaneova jednadžba odabrana je za matematički opis procesa biorazgradnje farmaceutika. Procijenjene vrijednosti biokinetičkih parametara μmax, Ks, Ki, Y i kd iznosile su 1,66 d−1; 46,2 g dm−3; 131,2 g dm−3; 0,23 gg−1; 0,002 d−1 za pokus s aktivnim muljem i 1,69 d−1; 44,3 g dm−3; 132,0 g dm−3; 0,22 gg−1; 0,001 d−1 za pokus s bioaugmentiranim aktivnim muljem. Bioaugmentacijom aktivnog mulja skratilo se vrijeme obrade otpadne vode za 24 sata. Učinkovitost procesa bioremedijacije u prosjeku je iznosila 64,8 % za sve provedene pokuse.In recent years, concerns about the occurrence and fate of pharmaceuticals that could be present in water and wastewater has gained increasing attention. With the public’s enhanced awareness of eco-safety, environmentally benign methods based on microorganisms have become more accepted methods of removing pollutants from aquatic systems. This study investigates bioremediation of pharmaceutical wastewater from pharmaceutical company Pliva Hrvatska d.o.o., using activated sludge and bioaugmented activated sludge with isolated mixed bacterial culture. The experiments were conducted in a batch reactor in submerged conditions, at initial concentration of organic matter in pharmaceutical wastewater, expressed as COD, 5.01 g dm–3 and different initial concentrations of activated sludge, which ranged from 1.16 to 3.54 g dm–3. During the experiments, the COD, pH, concentrations of dissolved oxygen and biomass were monitored. Microscopic analyses were performed to monitor the quality of activated sludge. Before starting with the bioremediation in the batch reactor, toxicity of the pharmaceutical wastewater was determined by toxicity test using bacteria Vibrio fischeri. The obtained results showed that the effective concentration of the pharmaceutical wastewater was EC50 = 17 % and toxicity impact index was TII50 = 5.9, meaning that the untreated pharmaceutical industrial effluent must not be discharged into the environment before treatment. The results of the pharmaceutical wastewater bioremediation process in the batch reactor are presented in Table 1. The ratio γXv ⁄ γX maintained high values throughout all experiments and ranged from 0.90 and 0.95, suggesting that the concentrations of biomass remained unchanged during the experiments. The important kinetic parameters required for performance of the biological removal process, namely μmax, Ks, Ki, Y and kd were calculated from batch experiments (Table 2). Figs. 1 and 2 show the experimental results of changes in concentrations of substrate γS0 = 5.01 g dm–3 for different initial concentrations of activated sludge in comparison to Endo-Haldane model. Changes in concentrations of activated sludge during four days of experiments P1 and P2 are presented in Figs. 4 and 5, respectively. These results suggest that the bioremediation process is well described by the selected model. Process efficiency of pharmaceutical wastewater treatment was approximately 64.8 % (Fig. 3), while in experiment P2 with bioaugmented activated sludge (Fig. 2), the same efficiency was obtained 24 hours earlier than in experiment P1 (Fig.1). Microscopic examination of the activated sludge (Fig. 6) showed that bioaugmentation has no effect on formation of the flocs, but increases efficiency of the bioremediation in a way that the pharmaceutical wastewater treatment is faster and more efficient with bioaugmented activated sludge (Table 3, Fig. 2)

Quantitative analysis and detection of chaptalization and watering down of wine using isotope ratio mass spectrometry

In early 1990's European Union has established new isotopic approach for detection of wine authenticity. In this article we setup the possibility of using new approach using new EIM - Module - IRMS (Ethanol Isotope Measurement - Module - Isotope Ratio Mass Spectrometry) instrumental technique and new analytical parameter delta D-n(delta H-2(n)) wine ethanol value, which represents delta H-2 value of non-exchangeable hydrogen stable isotope ratio in ethanol, with other isotopic species (delta O-18 values in wine water) to improve detection of illegal wine production practices such as addition of sugar and/or dilution with water. Total of 42 wine samples were analyzed. 10 wine samples (out of 42) were prepared from grapes by alcoholic fermentation and analyzed for delta D-n values of ethanol. 19 wine samples (out of 42) were collected from wine producers in Serbia plus 1 wine samples designated from United States was taken from Serbian market and analyzed for delta D-n values of ethanol, delta O-18 values in wine water and also delta C-13 values in wine ethanol. Furthermore 9 wine samples (out of 42) were taken from Hungarian market and analyzed for delta D-n values of ethanol, and also 3 wine samples (out of 42) were taken from Austrian market and analyzed for delta D-n values of ethanol. All experiments were done in 4 isotope laboratories located in US, Austria, Hungary and People's Republic of China. delta D-n values of ethanol were measured by using EIM Module connected to FlashHT 2000 pyrolizer (one laboratory - Imprint Analytics GmbH, Austria), while in other 3 laboratories (US - COIL - Cornell University, Stable Isotope Laboratory, Hungary - Isotoptech Ltd, Debrecen, Hungary and China - C.N.R.I.F.F.I. - China National Institute of Food and Fermentation Industries Limited) EIM Module was connected to TC/EA (High Temperature Conversion Elemental Analyzer). Peripherals in all laboratories were further interfaced with isotope ratio mass spectrometer. Furthermore delta O-18 values in wine water were measured by using Gas Bench II interfaced also with isotope ratio mass spectrometer (one laboratory - US). Obtained results from all 4 laboratories have shown that this new approach which uses delta D-n in wine ethanol is more effective in improving detection of illegal wine production practices (sugar enrichment and water dilution) and origin of ethanol, and also detecting the addition of corn or beet sugar, sugar syrup to wine, or dilution of grape must with water prior to alcoholic fermentation

Effect of Microstructural Changes during Annealing on Thermoelectromotive Force and Resistivity of Electrodeposited Ni 85.8

Ni85.8Fe10.6W1.4Cu2.2 alloy powder containing nanocrystals of an FCC-structured solid solution of iron, tungsten, and copper in nickel embedded in an amorphous matrix was electrodeposited from an ammonia citrate solution. The alloy exhibits thermal stability in the temperature range between 25°C and 150°C. Over the range 150−360°C, the alloy undergoes intense structural relaxation which considerably increases the electron density of states and, hence, its electrical conductivity. Less intense structural relaxation takes place at temperatures between 360°C and 420°C. In the temperature range of 420°C to 460°C, relatively more intense changes in the electron density of states at the Fermi level occur, as induced by the structural relaxation resulting from the stabilization of larger less mobile tungsten atoms and copper atoms. The large decrease in electrical resistivity and the high increase in the electron density of states at the Fermi level in the temperature range 460−520°C are due to amorphous matrix crystallization and FCC-phase crystal grain growth