Roman Slavík

Screening of the Spatial Distribution of Risk Metals in Topsoil from an Industrial Complex

Screening of the Spatial Distribution of Risk Metals in Topsoil from an Industrial Complex For the sustainable development of urban areas, it is necessary to identify if environmental pollution exists and where hot spot pollution sources lie. In this study, 280 topsoil samples were collected from an industry estate in Zlin (the Czech Republic). In these samples, the presence of toxic metal was analyzed by energy dispersed X-Ray fluorescence (ED-XRF), and statistical analysis revealed that the major anthropogenic contaminants in the topsoil were Pb, Zn and Sn. Further contaminant analysis by atomic absorption spectrometry (AAS) determined the maximum contents of 28558.47 mg/kg for Pb, 1132.35 mg/kg for Sn and 2865.22 mg/kg for Zn in selected topsoil samples. According to soil pollution index results, the main proportion of topsoil is contaminated, with the possible sources of contamination being traffic and a nearby municipal heating plant. This study proves that the combination of preliminary ED-XRF topsoil analysis, a multivariative statistical approach, AAS analysis and the geographical information system (GIS) is effective and together form a powerful tool for mapping topsoil contamination and conducting an environmental risk assessment. Przestrzenny rozkład metali niebezpiecznych w powierzchniowej warstwie gleby terenów uprzemysłowionych Dla zrównoważonego rozwoju obszarów miejskich istotna jest identyfikacja istniejących zanieczyszczeń środowiska i ich źródeł. Do badań pobrano 280 próbek wierzchnich warstw gleby z terenów zurbanizowanych miasta Zlin (Republika Czeska). W próbkach określono zawartość metali ciężkich metodą rentgenowskiej analizy fluorescencyjnej (ED-XRF). Na podstawie analizy statystycznej otrzymanych wyników stwierdzono, że główne zanieczyszczenia antropogenne w wierzchnich warstwach gleby to Pb, Zn i Sn. Dalsza analiza zanieczyszczeń metodą absorpcyjnej spektrometrii atomowej (AAS) pozwoliła na określenie maksymalnych stężeń tych analitów w próbkach: 28558,47 mg/kg dla Pb, 1132,35 mg/kg dla Sn i 2865,22 mg/kg Zn. Na podstawie przeprowadzonych badań stwierdzono, że główne źródła zanieczyszczeń to ruch samochodowy oraz pobliska ciepłownia miejska. Przeprowadzone badania dowodzą, że połączenie wstępnej analizy gleb metodą ED-XRF, metod statystyki wielowymiarowej, analizy AAS i Systemu Informacji Geograficznej (GIS) jest skutecznym narzędziem oceny zanieczyszczenia wierzchniej warstwy gleby i oceny ryzyka dla środowiska.

Initiating Biodegradation of Polyvinylpyrrolidone in an Aqueous Aerobic Environment: Technical Note / Zainicjowanie Biodegradacji Poliwinylopirolidonu W Środowisku Wodno-Tlenowym: Notatki Techniczne

Abstract A synthetic polymer, polyvinylpyrrolidone (PVP - E 1201) primarily finds applications in the pharmaceutical and food industries due to its resistance and zero toxicity to organisms. After ingestion, the substance passes through the organism unchanged. Consequently, it enters the systems of municipal wastewater treatment plants (WWTP) without decomposing biologically during the waste treatment process, nor does it attach (through sorption) to particles of activated sludge to any significant extent, therefore, it passes through the system of a WWTP, which may cause the substance to accumulate in the natural environment. For this reason the paper investigates the potential to initiate aerobic biodegradation of PVP in the presence of activated sludge from a municipal wastewater treatment plant. The following agents were selected as the initiators of the biodegradation process - co-substrates: acrylamide, N-acethylphenylalanine and 1-methyl-2-pyrrolidone, a substance with a similar structure to PVP monomer. The biodegradability of PVP in the presence of co-substrates was evaluated on the basis of biological oxygen demand (BOD) as determined via a MicroOxymax O2/CO2/CH4 respirometer. The total substrate concentration in the suspension equaled 400 mg·dm-3, with the ratio between PVP and the cosubstrate being 1:1, while the concentration of the dry activated sludge was 500 mg·dm-3. Even though there was no occurrence of a significant increase in the biodegradation of PVP alone in the presence of a co-substrate, acrylamide appeared to be the most effective type of co-substrate. Nevertheless, a recorded decrease in the slope of biodegradation curves over time may indicate that a process of primary decomposition was underway, which involves the production of metabolites that inhibit activated sludge microorganisms. The resulting products are not identified at this stage of experimentation. Abstrakt Syntetyczny polimer, poliwinylopirolidon (PVP - E 1201), znajduje zastosowanie przede wszystkim w przemyśle farmaceutycznym i spożywczym ze względu na jego odporność i brak toksyczności dla organizmów. Po spożyciu substancja ta przechodzi przez organizm niezmieniona. W związku z tym, że w procesie przetwarzania odpadów w komunalnym systemie oczyszczalni ścieków (OŚ) polimer ten nie ulega rozkładowi biologicznemu ani nie jest znacząco sorbowany w osadzie czynnym, może on gromadzić się w środowisku naturalnym. Ze względu na istnienie tych problemów w artykule przedstawiono możliwości aerobowej inicjacji biodegradacji PVP w obecności osadu czynnego miejskiej oczyszczalni ścieków. Jako inicjatory procesu biodegradacji zostały wybrane następujące środki: kosubstraty, akryloamid, N-acetylofenyloalanina i 1-metylo-2-pirolidon, substancje o strukturze podobnej do monomeru PVP. Biodegradację PVP w obecności kosubstratów oceniano na podstawie biologicznego zapotrzebowania na tlen (BOD), określonego za pomocą respirometru MicroOxymax O2/CO2/CH4. Całkowite stężenie substratu w zawiesinie wynosiło 400 mg · dm-3 dla stosunku PVP i kosubstratu wynoszącego 1:1 oraz dla stężenia suchego osadu czynnego wynoszącego 500 mg · dm-3. Chociaż nawet w tym układzie nie stwierdzono wzrostu biodegradacji samego PVP w obecności kosubstratu, to sam akryloamid okazał się najbardziej efektywnym rodzajem podłoża. Niemniej jednak, zauważony spadek nachylenia krzywych biodegradacji w czasie może wskazywać, że zachodzi proces rozkładu pierwotnego, który wiąże się z produkcją metabolitów hamujących aktywowane mikroorganizmy osadu. Otrzymane produkty nie zostały zidentyfikowane na tym etapie badań.

New microbial-friendly polyaniline nanoparticles on the base of nitrilotriacetic acid: comparison with PANI prepared by standard techniques

This paper describes the influence of polyaniline (PANI) nanoparticles prepared in the presence of the nitrilotriacetic acid (NTA) in comparison with PANI prepared by standard techniques, on mixed microbial cultures in the form of a biological extract from soil and activated sludge and partially digested sludge, both sourced from a municipal wastewater treatment plant. The presence of PANI prepared by standard techniques in aqueous environment has a negative effect on the activity of mixed microbial cultures in the form of activated sludge, digested sludge (anaerobic conditions), and natural soil. According to biological oxygen demand (BOD) values—respirometric test, the slight inhibiting effect of nanoparticles is attributed to impurities and oligomers from aniline polymerization. The use of NTA in the production of PANI, resulted in nanotubes with channels through which NTA is incorporated into the structure. A sample thus obtained shows higher values of BOD, which is associated with the fact that NTA is released from PANI nanotube channels followed by its biodegradation.

Polycondensation of Silicate with Hydroxocomplexes of Some Amphoteric Elements in Aqueous Solution

Reactions of aqueous solution of silicate with hydroxocomplexes of Al(III), Sn(IV), Zn(II) and Ga(III) have been experimentally studied. All studied reactions have produced gel in the whole volume of reaction mixture, and according to our hypothesis the essence of these reactions is polycondensation between silicate anions and anions of hydroxocomplex of the given amphoteric element, with formation of crosslinked inorganic polymer. Criterion for studying the course of the tested reactions has been the gel-point time of the reaction mixture. Dependences of the gel-point time on temperature, on KOH concentration and on molar ratios of silicate/amphoteric element in reaction mixture have been recorded. Products of the studied reactions have been analyzed by means of X-ray fluorescent spectrometry. All obtained results are in accord with the hypothesis of polycondensation reaction between silicate and hydroxocomplexes, and indicate that the reaction between silicate and hydroxoaluminate is merely one case of a more general chemical reaction.

Utilization of Waste Lignin and Hydrolysate From Chromium Tanned Waste in Blends of Hot-Melt Extruded PVA-Starch

The demand for biodegradable plastic material is increasing worldwide. However, the cost remains high in comparison with common forms of plastic. Requirements comprise low cost, good UV-stability and mechanical properties, as well as solubility and water uptake lead to the preparation of multi-component polymer blends based on polyvinyl alcohol and starch in combination with waste products that are hard to utilize—waste lignin and hydrolysate extracted from chromium tanned waste. Surprisingly the addition of such waste products into PVA gives rise to blends with better biodegradability than commercial PVA in an aquatic aerobic environment with non-adapted activated sludge. These blends also exhibited greater solubility in the water and UV stability than commercial PVA. Tests on the processing properties of the blends (melt flow index, tensile strength and elongation at break of the films) as well as their mechanical properties showed that materials based on these blends might be applied in agriculture (for example as the systems for controlled-release pesticide or fertilizer) and, somewhat, in the packaging sector.

Reaction between Silicate and Hydroxoaluminate Ions in Aqueous Solution

The chemical status and kinetics of the reaction between silicate ions and hydroxoaluminate ions (at Si/Al molar ratio 2:1) in KOH aqueous solution has been experimentally studied. It is assumed that condensation of OH groups bonded to silicon and aluminum occurs in this reaction forming a cross-linked polymer; and that the reaction represents the essence of synthesis of so-called geopolymer from alumino-silicate minerals. Time required for the change of the solution to a gel was measured as the reaction rate criterion. Measured dependences of the gel-point time on KOH concentration in the reaction solution exhibit a linear trend. The gel-point time decreases with increasing temperature. A measurable increase in pH value of the solution appears during the reaction. Measurement of the gel-point time for different Si/Al molar ratios has confirmed that the selected ratio 2:1 has been optimal. For a quantitative description of the reaction course and for explanation of the observed phenomena, the theories of polycondensation reactions and protolytic equilibria have been applied. Theoretically calculated dependences of the gel-point time on KOH concentration are in accord with experimentally determined values, which confirms anticipated polycondensation mechanism of the reaction under study.

Negative effect of clay fillers on the polyvinyl alcohol biodegradation: technical note

Abstract This work focuses on polyvinyl alcohol (PVA) biodegradation in the presence of mineral clays in an aqueous aerobic environment. PVA with a degree of hydrolysis of 88% and 72% was used for the experiments. The selected group of mineral clays (nanofillers for polymers) of montmorillonite (MMT) Cloisite® Na+; organo-modified montmorillonite (OMMT) Cloisite® 20A, Cloisite® 30B; waste kaolin; kaolin; and zeolites were prepared by synthesis of the aforementioned kaolins. The level of biodegradation was measured using a respirometer, Micro-Oxymax, and evaluated according to CO2 production. Results of this test indicate a negative effect on PVA biodegradability in the presence of MMT Cloisite® Na+ and Cloisite® 30B. It has been found that PVA biodegradability in the presence of no adapted inoculum was adversely affected by the biocidal effects of the organic modifier of Cloisite® 30B. In this case, PVA 88-8 biodegradation decreased by 71% and PVA 72-10 biodegradation dropped by 58%. Furthermore, the sorption of PVA on the Cloisite® Na+ in the range of 40%–45% was demonstrated in the following research.

PVP Based Materials: Biodegradation in Different Environments

Abstract The research deals with biodegradation of films prepared from polyvinylpyrrolidone and polylactic acid (PVP/PLA). Biodegradation of PVP/PLA films was supported by the following additives: 1-methyl-2-pyrrolidone, 1-octyl-2-pyrrolidone, acrylamide and N-acetyl-L-phenylalanine according to the previous study. The films were prepared by a solvent casting technique. Biodegradation was observed using the respirometric method in different environments. The films subjected to biodegradation were analyzed by scanning electron microscopy and Fourier transform infrared spectroscopy. It was found that the films are substantially degraded, but not in the biological way; PVP was quickly removed in presence of water because of its easy solubility. In contrast, this fact could support biodegradation of PLA, which becomes more available for microorganisms when PVP leaves PLA matrix.

Non-isothermal modeling of glycerol oxidation reaction and estimation of thermodynamic parameters

The paper presents determination of adiabatic temperature rise during the oxidation of glycerol to glyceraldehyde with hydrogen peroxide in order for estimating its potential hazardous behavior. Estimation of enthalpy of the reaction was carried out by using thermodynamic tables and the bond energy method. The Nonisothermal reaction system for glycerol oxidation was described on the basis of a dynamic modeling proposal, considering the energy balance in the reactor to describe the final stage in the process of glycerol oxidation. The objectives of the present study were determination of the physic-mathematical model for glycerol oxidation, performance of the linearization of the proposed model and determination of transfer function for control purposes.

Effect of hydrothermal treatment on the structure of an aluminosilicate polymer

AbstractThe effect of hydrothermal treatment on the structure of an aluminosilicate polymer prepared by a polycondensation reaction between silicate and hydroxoaluminate in alkaline aqueous solution was studied. The structural changes were investigated using X-ray diffraction analysis, Fourier-transform infrared spectroscopy, scanning electron microscopy imaging and thermogravimetric analysis. The results indicated that the amorphous aluminosilicate polymer transformed into a crystalline product during the hydrothermal treatment at 145°C. The crystalline phase was identified as a mineral of the zeolite group, most likely phillipsite. This transformation required an alkaline environment during the hydrothermal treatment.