Branimir Jovančićević

Bioaccumulation of Heavy Metals and Microelements in Silver Bream (Brama brama L.), Northern Pike (Esox lucius L.), Sterlet (Acipenser ruthenus L.), and Common Carp (Cyprinus carpio L.) From Tisza River, Serbia

The aim of this study was to determine the concentrations of Al, As, B, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sr, and Zn in liver, gills, gonads, and brain of four ecologically different fish species in Serbia: piscivorous northern pike, benthivorous sterlet and silver bream, and omnivorous common carp. Fish were caught at four sites along the stretch of the River Tisza in the Pannonian part of Serbia during October 2010. Results revealed that heavy metals and microelements with the highest values in fish samples were Fe, Al, and Zn. The highest concentration of heavy metals and microelements was recorded in omnivorous common carp, and organs that most intensively accumulated the greatest number of metals were liver and gills, whereas the locality did not exert a marked impact on level of bioaccumulation.

Structural analysis of Aleksinac oil shale kerogen by high-resolution solid-state 13C n.m.r. spectroscopy

Abstract A sample of kerogen from Aleksinac oil shale was examined by high-resolution solid-state 13C n.m.r. spectroscopy. The presence and relative proportions of kerogen structural units were estimated using a combination of NQS and T1ϱC methods with a peak-synthesis technique applied to the 13C CP—MAS spectrum. Relaxation parameters from these experiments were used to estimate differences in relative ‘mobility’ of various structural units. The kerogen was found to be highly aliphatic and to contain ∼ 79% long-chain aliphatic plus alicyclic structures, as well as ∼ 9% aromatic structures. These findings are in good agreement with the characterization of the same kerogen from its oxidation products.

Evaluation of the effects of native minerals on the organic matter of Aleksinac oil shale based on the composition of free and bound bitumens

Abstract In order to evaluate the adsorption and catalytic effects of indigenous carbonates and silicates on the organic matter of Aleksinac oil shale, the free and the bound bitumens were isolated and analyzed by organic geochemical methods. The differences in the gross compositions indicated an adsorption effect of both the carbonates and silicates in the examined oil shale. The maturation parameters, based on n-alkanes and isoprenoid alkanes pristane and phytane, indicated that bitumen 3 was of the highest, and bitumen 1 of the lowest, apparent maturity. The silicates were shown to have had a thermocatalytic effect on the organic matter of this sediment. Clay minerals had a catalytic effect primarily on sterane aromatization, rearrangement of steranes into diasteranes and their (20R) → (20S) isomerization. All evidence obtained by analysis of steranes and aromatic steroids suggested that the differences in bitumen compositions should be explained by the effect of clay minerals rather than by variations in the origin of the precursor biomass.

Investigation of the catalytic effects of indigenous minerals in the pyrolysis of Aleksinac oil shale substrates: Steranes, triterpanes and triaromatic steroids in the pyrolysates

Abstract Evidence for catalytic effects of indigenous minerals in the pyrolysis of Aleksinac oil shale kerogen was found by investigating the liquid products obtained in the Micro Activity Test (MAT) pyrolysis of raw shale and its demineralized substrates. By comparing the corresponding fragmentograms of a demineralized sample with those of a substrate containing only silicate minerals, differences in the side-chain isomerisation of the steranes and triterpanes, and in the side-chain cleavage of the triaromatic steroids were observed. These findings corroborated the previous conclusion, based on MAT parameters and TG weight losses, that the catalytic effect of the indigenous mineral components during the pyrolysis of Aleksinac oil shale kerogen is very low.

Modifications of Fullerenes Extractions and Chromatographies with Different Solvents

Abstract In the Bucky System II, based on electrical arc method, carbon soot was produced. Fullerenes C60 and C70 were Soxhlet extracted from the collected soot samples with toluene, chlorobenzene and with both of them successively, modifying the original methods. The yields of the both obtained toluene extracts were 5.4%. Chlorobenzene extract yield was 5.8%. After extraction of toluene insoluble soot with chlorobenzene, the entire extract yield was increased from 5.4% to 5.8%, due to modification of the existing methods. The difference of fullerenes solubilities in these solvents has been concluded. In the second part of our work toluene and chlorobenzene fullerenes extracts were separated by column chromatographies on active Al2O3, modifying the existing methods, by elution with hexane and mixtures of benzene, toluene, or xylene with hexane in determined ratios and orders. Identifications of buckminsterfullerene C60 in the first chromatographically purified fractions were achieved by electron impact ionization (EI) mass, IR, and UV/VIS spectroscopy. The second and the third purified fullerene fractions, toluene and chlorobenzene soot extracts were characterized by IR and UV/VIS methods.

Metals in the sediment and liver of four fish species from different trophic levels in Tisza River, Serbia

In aquatic environments metals originate from various natural and anthropogenic sources. The degree of contamination in fish tissues depends on the pollutant, fish species, their mode of feeding, sampling site and trophic level. This study presents concentrations of Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sr and Zn in sediment and liver of four ecologically different fish species: piscivorous northern pike (Esox lucius L.), benthivorous sterlet (Acipenser ruthenus L.) and silver bream (Brama brama L.), and omnivorous common carp (Cyprinus carpio L.). Fish were caught at four sites along the stretch of the River Tisza in Serbia during October 2010. The concentrations of metals have been assessed using the inductively coupled plasma – optical emission spectrometry. Results revealed that metals with the highest values in sediment and fish samples were Al and Fe, respectively and sometimes concentrations of Zn are in the same order of magnitude as Fe concentrations. The highest concentration of metals was recorded in omnivorous common carp.

Comparative Spectroscopic Characterization of the Basic and the Higher Fullerenes

The basic C60 and C70, and the higher fullerenes, mainly C76 and C84, were extracted by original procedures, with p-xylene and the mixture of xylenes from the samples of initial carbon soot, produced in electrical arc. The extracts were obtained in increased and high yields of 6% and 11.9%, respectively, due to application of the advanced procedures. The solubility of fullerenes in these solvents was compared. Chromatographic separation of the basic and the higher fullerenes from the obtained p-xylene extract was performed by continue elution, in one phase of the process, under atmospheric pressure, with original, defined gradient of solvents, from pure hexane to 75% toluene in hexane, on active Al2O3 column, by a new, improved method. Comparative spectroscopic characterization of the obtained purified fullerene fractions and the extracts is reported. The IR and UV/VIS techniques that have not been presented previously for the higher fullerenes were employed as a contribution to better introduction of their optical absorption properties.

Bioremediation of soil polluted with crude oil and its derivatives: Microorganisms, degradation pathways, technologies

The contamination of soil and water with petroleum and its products occurs due to accidental spills during exploitation, transport, processing, storing and use. In order to control the environmental risks caused by petroleum products a variety of techniques based on physical, chemical and biological methods have been used. Biological methods are considered to have a comparative advantage as cost effective and environmentally friendly technologies. Bioremediation, defined as the use of biological systems to destroy and reduce the concentrations of hazardous waste from contaminated sites, is an evolving technology for the removal and degradation of petroleum hydrocarbons as well as industrial solvents, phenols and pesticides. Microorganisms are the main bioremediation agents due to their diverse metabolic capacities. In order to enhance the rate of pollutant degradation the technology optimizes the conditions for the growth of microorganisms present in soil by aeration, nutrient addition and, if necessary, by adding separately prepared microorganisms cultures. The other factors that influence the efficiency of process are temperature, humidity, presence of surfactants, soil pH, mineral composition, content of organic substance of soil as well as type and concentration of contaminant. This paper presents a review of our ex situ bioremediation procedures successfully implemented on the industrial level. This technology was used for treatment of soils contaminated by crude oil and its derivatives originated from refinery as well as soils polluted with oil fuel and transformer oil.

Advancement of the Process for Extraction, Chromatography and Characterization of Fullerenes

In the first phase of this work, the basic C60 and C70 as well as the higher fullerenes, mainly C76 and C84, were Soxhlet extracted with p‐xylene and n‐heptane from the samples of carbon soot, produced in electrical arc, yielding 5.9% and 0.7% of the extract, respectively. The remaining, p‐xylene insoluble soot was then extracted with pyridine, by original advanced method, increasing the entire extract yield for an additional 5.9% to 11.8%. The procedures for increases of the basic and higher fullerenes yields, as well as for additional, selective extraction of the higher fullerenes were found. Chromatographic separation of the basic and the higher C76 and C84 fullerenes from p‐xylene extract was performed by continual elution, in one phase of the process, under atmospheric pressure, with original, defined, gradient of solvents from 5% toluene in hexane to pure 100% toluene, on active Al2O3 column, by a new, improved method. Identifications of the basic and the higher fullerenes in chromatographically purified fractions, as well as in the obtained extracts, were performed using determined techniques of IR and UV/VIS spectroscopy that have not been presented previously for the higher fullerenes.

Isolation and Characterization of the Higher Fullerenes from Carbon Soot

In the first phase of the process, the higher fullerenes, mainly C76 and C84, as well as the basic fullerenes C60 and C70, in a smaller amount, were Soxhlet extracted with pyridine from the sample of initial carbon soot, produced in electrical arc. The extract was obtained in increased, high yield of 16.4%, due to application of the original procedure. The solubility of fullerenes in this solvent was determined. Chromatographic separation of fullerenes from pyridine extract was performed by continual elution, in one phase of the process, under atmospheric pressure, with original, defined gradient of solvents, from pure hexane to pure toluene, on active Al2O3 column, by a new, improved method. Identifications of fullerenes in the obtained chromatographically purified fractions and pyridine extract of the initial soot were performed using determined IR and UV/VIS techniques that have not been presented previously for the higher fullerenes.