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

Waste-wood derived biochar as a support for horseradish peroxidase immobilization

In this paper, the suitability of waste-wood derived biochar particles as a support for the horseradish peroxidase (HRP) immobilization by adsorption method was investigated. The change in enzymatic activity of the immobilized enzyme at different values of pH and temperature, as well as stability over time, was measured. The results showed that HRP can efficiently bind to biochar particles by adsorption. The immobilized enzyme shows high activity (>80%) at a wide range of pH (7-9) and temperature (20-50°C). The immobilized enzyme retains 22% and 40% of its activity during storage at temperatures of 25 and 10°C after a period of 30 days, respectively

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

Green Alkali Activated Materials Based on The Different Precursors

The main goal of this study was the evaluation of physical–chemical, as well as radiological properties of residual materials used for synthesis of alkali activated materials (AAMs) for the possible application as new materials in a civil engineering industry. Also, the purpose of this research was to investigate the hydrophobicity of new alumino-silicate materials and the influence of Si/Al ratio on their surface properties. Contact angle measurement (CAM) as reliable indicator of hydrophobicity was determined for synthesized AAMs using water and ethylene glycol as reference liquids. Alkali-activated materials were synthesized from various precursors: kaolin, bentonite and diatomite. Characterization of phase structure and microstructure was performed by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Scanning electron microscopy and Energy-dispersive X-ray (SEM/EDX) spectroscopy. Contact angle measurements confirmed that the alkali-activated materials synthesized from metakaolin are the most porous, which can be explained by the smallest Si/Al ratio. The maximum value of contact angle and free surface energy (110.2 mJ/m2 ) has been achieved for alkali-activated materials synthesized by diatomite (GPMD). Concentration of 40K and radionuclides from the 238U and 232Th decay series in waste precursors, their metaphases and AAM samples synthetized by alkali activation were determined together with corresponding absorbed dose rate (D˙) and the annual effective dose rate. Natural activity concentrations in the alkali-activated materials were found to be lower than that of both residual materials and calcined ones