Distribution and profile of pollutants in bioticand abiotic samples by multivariate statisticalapproach

U okviru disertacije analizirano je prisustvo različitih postojanih zagađujućih materija u abiotskim i biotskim uzorcima iz različitih regiona, uključujući i uzorke zemljišta iz Novog Sada i okolnih naselja, i to zagađujuće materije organskog (policiklične aromatične ugljovodonike, polihlorovane bifenile i organohlorne pesticide) i neorganskog (teški elementi) porekla. Dobijeni rezultati uvršteni su u baze zajedno sa relevantnim podacima iz međunarodnih radova i na taj način formirane su baze koje prevazilaze lokalne interese pojedinačnih istraživanja. Primenom multivarijacionih metoda analize ovakvih baza utvrđen je stepen zagađenosti ispitivanih uzoraka u odnosu na rezultate iz literature, a takođe je razmatrana struktura formiranih multidimenzionalnih baza sa ciljem analize raspodele postojanih zagađujućih jedinjenja u posmatranim matriksima i identifikacije zajedničkih izvora zagađenja. Primenom različitih (matematičkih) predtretmana podataka u bazama, a zatim njihovom analizom izabranim multivarijacionim metodama, izvršena je procena uticaja predtretmana na rezultate i mogućnosti njihove interpretacije, kao i ispitivanje zavisnosti između posmatranih veličina i grupisanje uzoraka. Specifični ciljevi istraživanja su omogućili da se: - utvrde sličnosti i razlike pri korišćenju različitih načina izražavanja analitičkih rezultata (apsolutne vrednosti koncentracije nasuprot relativnih procentualnih udela, tzv. kompozicionih podataka) u okviru baza podataka i pri izdvajanju informacija iz multidimenzionalnih baza primenom multivarijacionih metoda, - utvrdi uticaj različitih načina pripreme (obrade) podataka pre primene multivarijacionih metoda radi dobijanja potpunijih informacija u cilju bolje interpretacije podataka i smanjenja dimenzija baza podataka; - ispitaju regionalne i vremenske razlike i/ili sličnosti između prisustva posmatranih jedinjenja u abiotskim i biotskim matriksima radi uočavanja dominantnih izvora zagađenja u određenim oblastima i vremenskim periodima uz istovremenu karakterizaciju eksperimentalno ispitanih uzoraka u odnosu na uzorke iz drugih regiona. Postignuti rezultati predstavljaju jedinstvene rezultate primene multivarijacionih metoda na bazama sastavljenim od podataka dobijenim u različitim istraživanjima iz sveta o prisustvu postojanih zagađujućih materija u izabranim abiotskim i biotskim uzorcima, doprinoseći tako analizi njihove opšte raspodele.Presence of different pollutant classes of both organic (polycyclic aromatic hydrocarbons, polychlorinated biphenyls and organochlorine pesticides) and inorganic origin (heavy elements) were analysed in abiotic and biotic matrices from various regions, including Novi Sad and its surrounding settlements. Obtained results with available data published in the international articles were included in the sets, forming the input matrices to be analysed by chemometric techniques. Analysis of the created sets of data by multivariate approach was performed due to determining pollution level of the investigated samples, as well to elucidate the persistent pollutants distribution and profiles in the selected matrices and to identify the common pollution sources. Using different treatments of a set of input data, influence of these procedures to results was assessed. Specific aims of investigation were: Determination of similarity and differences by using different ways of data expression (apsolute values of concentrations as apposed to relative percent fraction) in interpreration of multidimension data sets on the basis of multivariate statistical approach Determination of different processing of data before multivariate statistical methods due to obtaining adequate information for interpretation of data and reducing a set of original variables Examination of regional and temporal differences and/or similarity among presence of observed compounds in abiotic and biotic matrices due to identification of dominant pollutant sources as well as comparative characterisation of experimantally obtained data in relation to samples from another regions worldwide. Achieved results are unique examples of multivariate methods application on large data sets with results on the occurance of pesistent organic compounds in abiotic and biotic matrices obtained in different studies all over the world

Solid-phase extraction as promising sample preparation method for compound of emerging concerns analysis

Today’s environment is under the influence of numerous substances and most of them are not covered by current national and international regulations. Substances that are classified as contaminants of emerging concern, CECs, are not regulated nor systematically controlled in the environment, and they belong to the different chemical classes such as pesticides in current use, pharmaceutically active compounds (PhACs), personal care products, illicit drugs, hormones, micro- and nano-plastics, per- and poly-fluoroalkyl substances (PFAS), and many others. Once released CECs end up in surface water where they can be either accumulated or transported to the other environmental compartments, i.e. soil (by irrigation), underground water, or drinking water. The aim of the research was to investigate the efficiency of different selected solid-phase extraction (SPE) cartridges for preparation of water samples for simultaneous analysis of several CECs. For this purpose, a model mix solution of selected CECs in concentration relevant to environmental appearance was used. The selected CECs (14 PhACs, 11 pesticides in current use, and 4 PFAS) represented emerging contaminants with different properties, including polarities, and varying adverse effect on the environment and human health. Different types of sorbents were investigated: (i) commercial single-layer HLB, (ii) homemade multi-layer I: HLB plus a mix of WAX, WCX, and PPL, and (iii) multi-layer II: mix of WAX, WCX, and PPL plus HLB. The results revealed that the single-layer sorbent showed better efficiency in extraction of the analyzed CECs. Multi-layer sorbent should be further investigated to elucidate the possible reason for the poor extraction of some compounds, as development of a balanced extraction for a wider range of contaminants with different polarities, especially for non-target analysis of chemical residues, is required in order to capture the occurrence of the full profile of micropollutants

Isolation and characterization of carbendazim-degrading bacteria from agricultural soil samples

The use of chemical pesticides in agriculture generates many ecological and human toxicological problems. One of the most frequently used fungicides is carbendazim, however, in spite of its importance, there are only a few reports dealing with its microbial degradation in the environment. It has high acute ecotoxicological effect, as well as a suspected endocrine disruptor potential, so its residues in food and feed are dangerous. Until now, single isolates of Pseudomonas, Rhodococcus and Ralstonia have been found to be able to degrade carbendazim. Among fungi, one isolate of Alternaria alternata and Phanaerochete crysosporium were described as good carbendazim degraders. Bacterial degradation pathways have been partially explored: the first step is the hydrolysis of the carbamate group, followed by a ring-fission in 2-aminobenzimidazole resulting 1,2-diaminobenzene. This compound is further metabolized via the beta-ketoadipic acid pathway. As part of our studies on pesticide biodegradation, new carbendazim-metabolizing bacteria were isolated from Hungarian agricultural soil samples. These degrader bacteria were isolated from soil samples by microbiological enrichment methods. The molecular analysis revealed that the best isolates belong to the Variovorax paradoxus species. The isolate 10/1 was able to use carbendazim as sole carbon and nitrogen source. The pH optimum and temperature optimum for growth were found to be pH 6.3 and 30 °C, respectively. This isolate seems to be an efficient tool for the bioremediation of carbendazim polluted agricultural soils