Although the ubiquitous distribution of organophosphate esters (OPEs) in the environment has been documented very thoroughly, data on their occurrence in soil is so far sparse. In this study, an ...analytical method was developed to determine six OPEs in soil. The method consists of a combination of Twisselmann extraction and solid-phase microextraction (SPME), followed by gas chromatography−mass spectrometry (GC-MS). To develop the method, spiked soil was extracted using a Twisselmann extractor after freeze-drying. The extract was evaporated to dryness, redissolved, and filtered. A volume of 7 mL was then analyzed by SPME, followed by GC-MS. The effects of different parameters on analyte recoveries during sample preparation, e.g., solvent for Twisselmann extraction, solvent for redissolving the extract, addition of copper, and filtration of the extract, were systematically investigated. Under optimum conditions, 10 g soil samples were extracted using toluene, and the extract was redissolved in methanol/water (1:14) and filtered. It was not necessary to add copper. For TnBP, TBEP, TCPP, and TCEP, recoveries ranged from 77.0% to 89.6%. Those for TPP and TDCP were much lower, at 31.5% and 42.0%, respectively (addition level 22.9−45.8 ng g−1). The variability of recoveries under these conditions was between 0.3 and 16.2% (n = 3). Limits of detection (LOD) were 0.002−3 ng g−1. When ultrasonication was used in place of Twisselmann extraction in the developed method, recoveries were three to four times lower (27.4% to 30.6%), but the variability of recoveries was below 3% (n = 3). The method was applied to quantify OPEs in soil collected from the university campus in Osnabrueck (Germany). Average concentrations (n = 6) in soil samples ranged from 1.23 ng g−1 to 4.96 ng g−1 (dry weight) for TCPP, TPP, and TCEP. The results demonstrate for the first time that atmospheric deposition leads to soil contamination by OPEs.
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Development, characterization and evaluation of the efficiency of cost-effective medium for the removal of Pb2+, Cd2+ and Ni2+ from aqueous systems, as a novel, eco-friendly solution for wastewater ...remediation were done. The precursors for low-cost adsorbent were lignocellulosic raw materials (sweet/sour cherry kernels), as industrial byproducts and components of organic solid waste. Activated carbon synthesis was carried out by thermochemical conversion (H3PO4, 500 °C) in the complete absence of inert atmosphere. Characterization of the activated carbon was performed by elemental analysis, FTIR, SEM, EDX and BET. BET surface area corresponds to 657.1 m2 g−1. The evaluation also included the influence of pH, contact time, solute concentration and adsorbent dose on the separation efficiency in the batch operational mode. The equilibrium and kinetic studies of adsorption were done. The maximum adsorption capacity of the activated carbon for Cd2+ ions was calculated from the Langmuir isotherm and found to be 198.7 mg g−1. Adsorption of Pb2+ and Ni2+ were better suitable to Freundlich model with the maximum adsorption capacity of 180.3 mg g−1 and 76.27 mg g−1, respectively. The results indicate that the pseudo-second-order model best describes adsorption kinetic data. Based on desorption study results, activated carbon was successfully regenerated with HNO3 for 3 cycles. In order to provide the results for basic cost-effective analysis, competing ion-effects in a real sample have been evaluated.
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•Pb2+, Cd2+ and Ni2+ removal on cherry kernels activated carbon were studied.•Low-cost activation develops large pore volume with 657.1 m2 g−1 surface area.•The sorption capacity with 171.4 mg g−1 mainly depends on the surface chemistry.•The produced adsorbent could be applied into wastewater treatment.•Our approach was simple and inexpensive.
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The municipal solid waste landfill in Novi Sad, Serbia is in its operative status from early 1980s and represents potential significant source of environmental compartments pollution and the threat ...to human health as a result of undeveloped waste management practice. Residues of Polycyclic Aromatic Hydrocarbons (PAHs) and Persistent Organic Pollutants (POPs) as toxic, mutagenic, teratogenic and carcinogenic chemicals were investigated in ambient air of landfill site in Novi Sad. Passive air sampling technique was used for the purpose of ambient air sampling. Total risk to the human health is calculated as a sum of individual risks for each group of substances according to the recommended United States Environmental Protection Agency (US EPA) methodology. The overall results indicate that the landfill site in Novi Sad does not pose a relevant treat to human by inhalation of PAHs and POPs. The effect of low concentrations, non-monotonic dose response, synergistic and amplifying effects of chemical complexes must be highly respected while performing future health risk assessment.
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•Passive air samplers were used for determination of PAHs and POPs on landfill.•Limited information on levels of PAHs and POPs in Serbia•Waste management practice in Serbia consists of collection and land disposal.•The results were used for health risk assessment.
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The paper investigates the effect of silver nanoparticles preparations on the rate of burn healing and scar quality. Three preparations for burn treatment were considered: one with silver ...sulfadiazine and two with silver nanoparticles woven into two types of dressing: one, of polyethylene and second, carboxymethyl cellulose. The experiment was performed on pigs, due to anatomical and pathophysiological similarities with human skin. All three silver preparations have antimicrobial properties with a beneficial effect on the healing of burns. Preparations with silver nanoparticles proved to be the most effective, since they encourage very fast burn epithelialization, affect reduction of the level of matrix metalloproteinase-9 in the environment of the burn wound, lead to faster expression of vascular endothetial growth factor ? VEGF, cause less thickening of the epidermis and contractility, and improve tension characteristics of the scar compared to the preparation with silver sulfadiazine. By comparing results of healing parameters and evaluation of the scar achieved with preparations with silver nanoparticles, it was evident that the best overall results of local treatment were achieved with silver nanoparticles in crystalline form. Due to quantum-mechanics, surface and chemical oxidation?reduction (reactive oxygen species) phenomenological characteristics Ag nanoparticles in crystalline form have unique ability to catalyze rate of healing.
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Dissecting a human cadaver is an irreplaceable practice in general training of medical students. Cadavers in anatomy laboratories are usually preserved in formalin, an embalming fluid whose basic ...component is formaldehyde (FA). The aim of this study is to assess the cancer risk of employees and students that are exposed to FA based on the results of three monitoring campaigns, as well as to suggest permanent solutions to the problem of FA exposure based on the results obtained. Three sampling campaigns of formaldehyde concentration in indoor environments were conducted at five different locations at the Anatomy Department of the Faculty of Medicine with the purpose of assessing permanent employees’ and medical faculty first year students’ exposure to FA. Indoor air was continuously sampled during 8 h of laboratory work and analyzed in accordance with the NIOSH Method 3500. Exceeding of the 8 h time-weighted average (8 h TWA) values recommended by Occupational Safety and Health Administration (OSHA) of 0.75 ppm was recorded in 37% of the samples during the three-month monitoring campaign. Cancer risk assessment levels for permanent employees were in the range from 6.43 × 10−3 to 8.77 × 10−4, while the cancer risk assessment levels for students ranged from 8.94 × 10−7 to 1.83 × 10−6. The results of the research show that cancer risk assessment for employees is several thousand times higher than the limit recommended by the EPA (10−6) and point to the importance of reducing exposure to formaldehyde through the reconstruction of the existing ventilation system, continual monitoring, the use of formaldehyde-free products, and plastination of anatomical specimens.
The Serbian National Waste Management Strategy for the Period 2010–2019, harmonized with the European Union Directives, mandates new and very strict requirements for landfill sites. To enable ...analysis of a number of required qualitative and quantitative factors for landfill site selection, the traditional method of site selection must be replaced with a new approach. The combination of GIS and the Analytic Hierarchy Process (AHP) was selected to solve this complex problem. The Srem region in northern Serbia, being one of the most environmentally sensitive areas, was chosen as a case study. Seventeen factors selected as criteria/sub-criteria were recognized as most important, divided into geo-natural, environmental, social and techno-economic factors, and were evaluated by experts from different fields using an AHP extension in Arc GIS. Weighted spatial layers were combined into a landfill suitability map which was then overlapped with four restriction maps, resulting in a
final suitability map
. According to the results, 82.65% of the territory of Srem is unsuitable for regional landfill siting. The most suitable areas cover 9.14%, suitable areas 5.24%, while areas with low and very low suitability cover 2.21 and 0.76% of the territory, respectively. Based on these findings, five sites close to two large urban agglomerations were suggested as possible locations for a regional landfill site in Srem. However, the final decision will require further field investigation, a public acceptance survey, and consideration of ownership status and price of the land.
The paper researches water quality, supply and management system assessment problems of the Montenegrin costal region. A significant problem is generated by seasonal tourism, the main branch of ...Montenegrin costal economy. The selected performance indicators model has been tested in the water supply system of the city Herceg Novi, as a representative experimental system for the Montenegrin costal area. The city Herceg Novi has 33.000 permanent residents and around 80.000 individual consumers during the summer touristic season. The research activities are based on the seasonal parameters defined by the monitored performance indicators of the water supply system. The study depicts the developed indicators performance model based on the obtained experimental monitoring data. Within the experimental analytical research performance an indicator matrix was established. The coastal area of Montenegro is experiencing over 50 % of water loss. Structure developed in the model applies the performance indicators and results in systematic losses reduction. The model takes into account the principle of seasonality, and the existence of two completely different periods of the year. This type of the experimental research with testing in situ was for the first time performed and implemented in the costal Adriatic region of Montenegro.
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Having in mind that there is a general lack of monitoring plans and precaution measures in the developing countries and that the Danube is the second longest river in Europe, the estimation of the ...relevant concentration levels of unregulated xenobiotics is a topic of interest both on local and international level. The selected pharmaceuticals, caffeine, and benzotriazole presented in the collected water samples from seven representative locations around the territory of Novi Sad, Serbia, during 1-year period, were analyzed with the use of solid-phase extraction followed by the liquid chromatography coupled with triple quad tandem mass spectrometry. The most frequently detected compounds were caffeine and carbamazepine in the concentrations up to 621 and 22.2 ng/L, respectively, while the maximum concentration of the analyzed pharmaceuticals was obtained for ibuprofen (60.1 ng/L). The presence of benzotriazole along the analyzed section of the river was confirmed in the concentration levels up to 26.7 ng/L. Although sulfamethoxazole and desmethyldiazepam were detected at trace levels (0.22 and 3.41 ng/L, respectively); the presence of these pharmaceuticals in complex mixtures should not be neglected. Due to the frequent detection caffeine, carbamazepine, ibuprofen, and benzotriazole could be proper candidate for hydrophilic anthropogenic markers for quantification of wastewater contamination in surface water in the analyzed Danube section.
•The Danube water quality was predicted using macrophyte binary data.•The developed model showed good predictive performances in the main river channel.•The sensitive analysis selected 28 macrophytes ...as significant water quality indicators.
Ecological assessment of large rivers such as the Danube is a challenging task. Eutrophication was reported as one of the main drivers that structure aquatic communities in the Danube basin. Due to their sedentary nature, relatively slow growth/ long life spans, and engineering role in aquatic ecosystems, macrophytes are widely used in the detection of nutrient enrichment. In this study, macrophyte presence-absence data within the 3 km long reaches obtained from the Joint Danube Survey (JDS3) were used to predict the water quality of the Danube river and its main tributaries. For each water quality variable (dissolved oxygen, nitrate-nitrogen, and orthophosphates), a multi-layer feed-forward artificial neural network model (ANN) was constructed using the macrophytes as explanatory variables. Despite the limited number of samples (123) along the wide trophic gradient of the Danube, the model showed good predictive performances for the main river channel. The highest discrepancy between observed and predicted water quality was obtained for the samples collected in the tributaries or downstream from the tributaries' mouth, where the model predicted better trophic conditions compared to measured ones. From 64 analysed macrophyte species, 28 were selected by sensitivity analysis as key water quality indicators (KIS) for at least one environmental variable. KIS mainly belonged to the eutrophic tolerant submerged or emerged species with broad ecological amplitude, which reflects the significance of the developed model for use on rivers subjected to nutrient pollution. However, the use of the developed predictive model is restricted to the river sections having a water velocity suitable for macrophytes growth. The developed ANN architecture represents the modelling approach which could be applied to other lotic systems and biological quality elements.
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The new approach of the study was to assess the consistency between the gas?particle partition coefficients of 16 EPA (Environmental Protection Agency) polycyclic aromatic hydrocarbons (PAHs) ...predicted by the Dachs?Eisenreich ab/adsorption model and the experimental results obtained within the field measurements. A total number of 29 air samples was obtained at 9 locations in Serbia. High volume air sampler was applied, with quartz filters for collecting the atmospheric particles and polyurethane foam filters (PUF) for retaining the free gas molecules of PAHs. The results predicted by the model and the experimental data were compared. The deviations between the measured and predicted f (fraction) values were less than one order of magnitude for Flo, Phe, Ant, Flu, Pyr, B(a)A and Chr. For the PAHs with high molecular mass, B(b)F, B(k)F, B(a)P, I(1,2,3-cd)P, D(ah)A and B(ghi)P, very good agreement was confirmed, except for the data measured at the Oil refinery in Pancevo. The applied model underestimated the concentrations of PAHs in gasphase for the low-molecular mass PAHs.
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