Improvement of methods for extraction and determination of constituting and polluting elements in coal and fly ash.

Sagorevanje uglja, zajedno sa njegovom eksplatacijom, odlaganjem pepela i drugim pratećim procesima, predstavlja glavni izvor potencijalno toksičnih elemenata koji zagađuju čovekovu okolinu, kao što su: As, Be, Cd, Cr, Hg, Pb, Sb, Th, U i drugi. Istraživanja i praćenje negativnih uticaja mikroelemenata na životnu sredinu imaju izuzetan značaj. Naročito je značajno identifikovanje i praktična primena novih pristupa, metoda, tehnika i uređaja u proceni uticaja zagađivačkih elemenata na životnu sredinu. Ispitivanja imaju za krajnji zadatak da se pronađu ekonomičnije i efikasnije alternative za skladištenje pepela na deponijama i izračunavanja potencijalnog zagađenja iz uglja i pepela. U ovom radu ispitana je mobilnost i dostupnost metala i neorganskih anjona iz uglja i elektrofilterskog pepela. Uzorci uglja su uzorkovani iz Kostolačkog basena, a pepeo je proizvod sagorevanja uglja Kostalačke termoelektrane. U cilju simulitanja ponašanja elemenata u uslovima životne sredine i ispitivanja ispiranja elemenata u životnu sredinu uzorci su ekstrahovani destilovanom vodom. Korišćene su različite tehnike ekstrahovanja: rotaciono mućkanje, ultrazvučna i mikrotalasnu ekstrakcija. Inetrakcije matriksa sa vodom ispitane su promenom ekstrakcionih vremena i temperature mikrotalasne ekstrakcije. Određivane su koncentracije elemenata: Al, As, Be, Ca, Cd, Co, Cr, Fe, Hg, K, Mg, Mn, Na, Ni, Pb, Sb i Se metodom indukovano sregnute plazme sa optičkom emisionom spektrometrijom (ICP-OES). Konstituenski elementi: K, Na, Ca i Mg paralelno su određeni jonskom hromatografijom (IC). Takođe, i dostupni konstituentni i zagađivački neorganski anjoni su određeni jonskom hromatografijom. Tačnost i pouzdanost rezultata proverena je merenjem koncentracije fluorida jon selektivnom elektrodom, kao i korišćenjem sertifikovanog referentnog materijala. Budući da se mikrotalasna ekstrakcija pokazala bržom i efikasnijom od druge dve tehnike, u daljem radu je uticaj mikrotalasa primenjen za sprovođenje sekvencijalne ekstrakcije...Coal combustion along with its exploitation, ash disposal and other related processes constitutes the main source of potentially toxic elements that cause environmental pollution, such as As, Be, Cd, Cr, Hg, Pb, Sb, Th, U and others. It is very important that negative effects of microelements on the environment be thoroughly researched. They also require systematic and continuous monitoring. Another major task is to identify and adopt in practice new approaches to environmental impact assessments for pollutant elements. New methods, techniques and devices need also to be developed and applied. The end goal of this investigation was to find more cost-efficient and effective alternatives for ash storage at landfills and methods for calculating the level of potential pollution caused by coal and ash. The investigation involved tests for mobility and availability of metals and inorganic anions from coal and fly ash. Coal samples were collected from the Kostolac mine, while ash samples were the products of combustion of coal from the Kostolac thermal power plant. In order to simulate the actual behavior of elements and the process of their leaching into the environment, the samples were extracted using deionized water. Various extraction techniques were used, such as a rotary shaker, ultrasonic and microwave assisted extraction. Matrix interactions with water were investigated by varying the times and temperatures of microwave assisted extraction. Inductively coupled plasma optic emission spectrometry (ICP-OES) was used to measure the concentrations of the following elements: Al, As, Be, Ca, Cd, Co, Cr, Fe, Hg, K, Mg, Mn, Na, Ni, Pb, Sb and Se. The constituent elements, namely K, Na, Ca and Mg were identified in parallel by employing ion chromatography. The accuracy and reliability of obtained results was verified by measuring the concentration of fluorides using an ionselective electrode as well as certified reference material..

Research correlation vegetation index of corn with speed of movement sensor and elevation of field

This paper presents field scouting of corn in order to determine the content of nitrogen in the green parts of the plants. The aim was to measure the vegetative index using two optical sensors by OptRx AGL Technology. The sensors are positioned at a distance of 3.5 m, individually observing five rows of corn. The speed of movement of the tractor and also elevation of field are varied. The measured vegetative index of the plants is correlated, in first, with the speed of the sensor on the platform. The measured vegetative index of the plants is correlated after that with elevation also. Both of that case are shown that the Normalised Difference Red Edge (NDRE) as represent of vegetative index is not correlated with speed and elevation. This Results represented with Pearson Correlation Coefficient and Spearman's Correlation Coefficient are statistical signatifical. This conclusions are valid only for short rang of speed and elevation research. Average speed was 6,39 km/hr and rang of elevation was 1.6 m (106.8-108.4 m)

The European perch (Perca fluviatilis) as an indicator of OCPs pollution in different types of reservoirs in Serbia

The aim of this study was to determine the concentrations of 17 organochlorine pesticides (OCPs) in muscle tissue of the European perch from six reservoirs in Serbia with different properties and used for different purposes: electricity generation (Vlasina, Zaovine, and Perućac), recreation (Lake Sava), and water supply (Garaši). A gas chromatography with mass spectrometric detection (GC-MS) was used for OCPs detections. The concentrations of aldrin, dieldrin, endrin, endrin aldehyde, α-HCH, β-HCH, γ-HCH, δ-HCH, endosulfan I, endosulfan II, endosulfan sulfate, 4,4′-DDT, heptachlor epoxide, and metoxychlor were not detected at any studied reservoir. On the other hand, we detected concentrations of 4,4′-DDE in one individual (17 μg kg-1) from Garaši, 4,4′-DDD in one individual (15 μg kg-1) from Garaši and two individuals (15 μg kg-1, 17 μg kg-1) from Zaovine, as well as heptachlor in two individuals (12 μg kg-1, 15 μg kg-1) from Zaovine and three individuals (9 μg kg-1, 11 μg kg-1, 12 μg kg-1) from Lake Sava. Concentrations of analyzed OCPs did not exceed the proscribed maximum residue levels (MRLs). Therefore, we can conclude that meat of European perch from all investigated reservoirs is safe for human consumption regarding these pesticides

Mutual impact of different parameters in yield monitoring

Pri merenju i analizi lokacijski specifičnog prinosa poznatijeg kao monitoring prinosa u okviru šireg ciklusa precizne poljoprivrede meri se oko 30 parametara od interesa za mapiranje prinosa i šire. Najvažniji parametri uz podrazumevana tri parametra koja definišu lokaciju (latituda, longituda i elevacija) su maseni prinos zrna i vlažnost zrna. Uz ove podatke tokom monitoringa prinosa u ovom radu posmatrani su i temperatura zrna, brzina kretanja kombajna i odstupanje preciznosti lociranja (DOP). Jednostavnim statističkim testiranjem korelacije između ovih parametara utvrđen je nivo međusobnog uticaja, između ostalog i stepen uticaja svih navedenih i posmatranih parametara na prinos, kao odgovor na istraživačko pitanje da li na prinos utiče još neki parametar osim lokacije i fizičko-hemijskih osobina zemljišta na toj lokaciji. Utvrđen je različit stepen uticajnosti, ali nije otkriven ni jedan značajan dodatni uticaj na prinos izračunat posredstvom merenja i makon samog merenja. Za monitoring prinosa pri žetvi semenske pšenice na imanju 'Mladost' PKB, Tabla 2, korišćen je kombajn Class Lexion 450 sa nadograđenim sistemom za monitoring AGL Technology proizvođača. Za statističku analizu korišćena je parametarska metoda korelacije u okviru softverskog paketa SPSS Statistics v.21.When measuring and analyzing site-specific yield known as the yield monitoring within a wider cycle of precise agriculture, about 30 parameters are measured from inertia for mapping yields. The most important parameters with the default three parameters that define the location (latitude, longitude and elevation) are mass grain yield and grain moisture. In addition to this data during the yield monitoring, the temperature of the grain, speed of the combine and delution of precision (DOP) were also observed in this paper. By simple statistical testing of the correlation between these parameters, the level of mutual influence was determined, among other things, the degree of influence of all mentioned and observed parameters on yield, in response to the research question whether the yield affects another parameter other than the location and physical and chemical properties of the land at that location . A different degree of influence was determined, but no significant additional impact on the yield was calculated by measuring and measuring the measurement itself. For the monitoring of the yield of seed wheat harvesting on the 'Mladost' PKB, Tabla 2, the Class Lexion 450 harvester with an upgraded system for monitoring the AGL Technology manufacturer was used. For the statistical analysis, the parametric method of correlation within the software package SPSS Statistics v.21 was used

Canine Dirofilaria Infections in Two Uninvestigated Areas of Serbia: Epidemiological and Genetic Aspects

In 2009 canine filarial infections were investigated in two northern areas of Serbia (Pancevo and Veliko Gradiste), applying morphometry, biochemical staining, and immunological kit to detect Dirofilaria immitis antigens, and two home-made ELISAs to detect antibodies to D. repens and D. immitis somatic/metabolic polyproteins. Moreover, molecular tools were applied to analyze the phylogenetic relationships of the isolates. The microfilariae detected in 21/122 dogs (17.2%) were identified as D. repens (n = 21) and D. immitis (n = 2). D. immitis antigens were found in another 13 animals with occult infection. All of the 15 heartworm-positive dogs also had antibodies to this parasite, which were detected in another 13 subjects, indicating an overall D. immitis seroprevalence rate of 22.9%. Serology for D. repens revealed evidence of antibodies in 42.6% of the dogs, but was negative for 4 microfilaremic dogs. As for the two different areas, the prevalence of microfilariae and/or D. immitis antigens, mainly due to D. repens microfilaremic animals, was not significantly higher in Veliko Gradiste (33.3%) than in Pancevo (22%). However, serology showed a different epidemiological picture. Heartworm infection occurred more often in both areas, and antibodies to dirofilarial nematodes were detected in 72.9% of dogs living in Pancevo, a rate higher than in those living in Veliko Gradiste (57.1%). No risk factors for infection were found, confirming the uselessness of prophylactic drugs against D. repens, and suggesting the presence in these areas of sunrise- or sunset-biting mosquitoes as important vectors. The results indicate the need for both appropriate entomological studies and further research on the intra-species variability shown by D. repens

Aqueous extraction of anions from coal and fly ash followed by ion-chromatographic determination

Three different techniques were applied for the aqueous extraction of anions from coal and fly ash: rotary mixer-and ultrasonic-assisted extraction with different duration time, and microwave-assisted extraction at different temperatures. Validation showed that the ion-chromatographic method was suitable for the analysis of anions in coal and fly ash extracts. The variations in the amounts of anions using different extraction times during rotary-assisted extraction were minimal for all investigated anions. The efficiency of ultrasound-assisted extraction of anions from coal depended on the sonication time and was highest at 30 min. The ultrasound-assisted extraction was less efficient for the extraction of anions from fly ash than rotary-assisted extraction. Increase of temperature in the microwave-assisted extraction had a positive effect on the amounts of all anions extracted from coal and sulphate from fly ash, while the amounts of fluoride and chloride in fly ash extracts decreased. The microwave-assisted extraction of coal at 150 degrees C was compared with standard ASTM methods, and results were in good agreement only for chloride. Changes in the pH value and conductivity during ultrasound-assisted extraction were measured in order to explain changes on the surface of coal particles in contact with water and different processes that occur under environmental conditions

Two Age Groups of Adult Pikeperch ( Sander lucioperca ) as Bioindicators of Aquatic Pollution

Pikeperch of age classes 3+ and 4+ were collected from the Garaši reservoir (Serbia) to analyze their bioindicator potential and compare their possible differences. Concentrations of 26 elements were determined in gills, muscles, and liver by inductively-coupled plasma optical emission spectrometry (ICP-OES) and of 17 organochlorine pesticides (OCPs), and six polychlorinated biphenyls (PCBs) in muscle by gas chromatography with mass spectrometric detection (GC-MS). Histopathological changes in the liver and gills were analyzed as biomarkers of general fish health. Only the concentrations of Cd, Na, and P in the muscles differed significantly. The OCPs and PCBs concentrations were below the detection limits, so fish meat consumption does not pose a risk concerning these substances. Hg and Cd exceeded the maximum allowed concentrations in some 4+ individuals, probably due to biomagnification. Gills were the most affected by metal exposure in both age classes. Histopathological changes and indices were minor and did not differ significantly between age classes, suggesting that pollution did not affect the morphology and structure of gills and liver. There were no significant correlations between elemental accumulation and fish condition or between histopathological scores. Therefore, both age classes can be used as bioindicators of pollution

Ispitivanje adsorpcije fenola na makroporoznim polimernim adsorbensima

This work reports results on phenol adsorption from aqueous solution by porous copolymers based on glycidyl methacrylate: two samples of macroporous crosslinked poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate), were synthetized by suspension copolymerisation with ethylene glycol dimethacrylate. In addition, the two copolymer samples were functionalized with ethylene diamine. The amounts of adsorbed phenol were presented in the form of adsorptions isotherms, which were interpreted using Langmuir, Freundlich and Sips' equations. The first was found to express high level of agreement with experimental data. Phenol adsorption indicate the homogeneous distribution of active sites present on the investigated polymers. It was found that adsorption of phenol on copolymers is fast and depends on the presence of amino groups and on the pore size. From the obtained results, it was possible to distinguish macroporous polymer as a material which possesses the capacity for adsorption of phenol comparable to that of activated carbon.Ovaj rad se bavi proučavanjem adsorpcije fenola iz vodenih rastvora na kopolimerima različitih poroznih karakteristika i polarnosti. Korišćeni adsorbensi se baziraju na glicidil metakrilatu: dva uzorka makroporoznog poli(glicidil metakrilat-co-etilen glikol dimethakrilat) su sintetisani suspenzionom kopolimerizacijom sa etilen glikol dimetakrilatom. Dodatno, dva kopolimera su funkcionalizovani sa etilen diaminom. Količina adsorbovanog fenola je predstavljena u vidu adsorpcionih izotermi, koje su interpretirane korišćenjem Langmuir-ove, Freundlich-ove i Sips-ove jednačine: prva od ovih daje visok nivo slaganja sa eksperimentalnim podacima. Adsorpcija fenola ukazuje na homogenu raspodelu aktivnih mesta prisutnih u ispitivanim polimernim sistemima. Rezultati dobijeni u ovom istraživanju pokazuju da adsorpcija fenola na ispitivanim kopolimerima zavisi od prisustva amino grupa i od veličine pora. Adsorpcija fenola iz vodenih rastvora je brza u slučaju svih korišćenih adsorbenasa. Na osnovu dobivenih rezultata, može se zaključiti da su makroporozni polimeri materijali čije je adsorpcioni kapacitet za fenol uporediv sa onim koji ima aktivni ugalj

Comparison of sequential and single extraction in order to estimate the environmental impact of metals from fly ash

The aim of this paper is to simulate leaching of metals from fly ash in different environmental conditions using ultrasound and microwave-assisted extraction techniques. Single-agent extraction and sequential extraction procedures were used to determine the levels of different metals leaching. The concentration of metals (Al, Fe, Mn, Cd, Co, Cr, Ni, Pb, Cu, As and Be) in fly ash extracts were measured by inductively coupled plasma-atomic emission spectrometry. Single-agent extractions of metals were conducted at sonication times of 10, 20, 30, 40 and 50 min. Single-agent extraction with deionized water was also performed by exposing samples to microwave radiation at temperature of 50 degrees C. The sequential extraction was conducted according to the BCR procedure which was modified and applied to study the partitioning of metals in coal fly ash. The microwave-assisted sequential extraction was performed at different extraction temperatures: 50, 100 and 150 degrees C. The partitioning of metals between the individual fractions was investigated and discussed. The efficiency of the extraction process for each step was examined. In addition, the results of the microwave-assisted sequential extraction are compared to the results obtained by standard ASTM method. The mobility of most elements contained in the fly ash is markedly pH sensitive

LUNGWORM INFECTION OF SMALL RUMINANT IN BELGRADE AREA

The grazing diet allows the permanent contact of small ruminants with intermediate hosts and the eggs and larval forms of the parasite. From these reason parasitic infections are present worldvide in a large number of herds. Lungworms of domestic ruminants are nematodes that belongs to the phylum Nemathelmenthes commonly named as round worms; classified under the super family Trichostrongyloidea and Metastrongyloidea of which Dictyocaulus and Protostrongylus are causes of lungworm infection in ruminants. They induce verminous pneumonia which was a significant health problem of small ruminant. Due to their importance in the pathology of small ruminants, in 2020 we conducted a survey of their presence in the Belgrade area. Investigations included 23 herds. In total, 250 fecal samples were examined by the Berman method. Determination of parasites was based on its morphological characteristics. Dictyocaulus filaria was ocurerd at 23.20% of small ruminants heards. The highest prevalence is observed in the places where predominate flat plain pastures. Due to microclimatic conditions, the infection usually occurs in the period April-May when the largest number of animals are grazing. Clinically manifested disease occurs in kids and lambs that are grazed for the first time in the second half of the grazing season. Protostrongylinae are biohelminthes and need intermediate hosts for their development - snails and slugs. Due to microclimatic conditions, the infection usually occurs in the March and April when the largest number of intermediate host are preset at pasture. Protostrongylus rufescens occurred on 21.22%. These nematodes live in bronchioles and alveoli. The prevalence ranges was from 4.23%. Based on the results obtained, we can conclude that a large number of sheep and goats in Belgrade are infected with pulmonary strongilides. Dictyocaulus filaria and Protostrongylus rufescens are the dominant species, while Muellerius capillaris are present in a smaller percentage