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Your search keyword '"Cyganowski, Piotr"' showing total 201 results
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201 results on '"Cyganowski, Piotr"'

1. Nanocomposite membranes with Au nanoparticles for dialysis-based catalytic reduction-separation of nitroaromatic compounds

Author

Cyganowski, Piotr and Wolska, Joanna

Subjects
Physics - Applied Physics, Condensed Matter - Materials Science
Abstract

Apart from the fact that nitroaromatic compounds (NARs) have toxic and mutagenic characteristics, they are also essential substrates for the synthesis of aromatic amines (AAMs). In this context, the present study presents a new approach that enables NAR-contaminated wastewaters to be treated as a reagent for the synthesis of AAMs. It involves the fabrication of anion exchange membranes with Au nanoparticles (AuNPs) that simultaneously reduce 4-nitrophenol (4-NP) and separate the resultant 4-aminophenol (4-AP) via. the dialysis mechanism. The nanocomposite membranes were prepared by amino-modification of poly(vinyl chloride) films obtained in the presence of cyclohexanone (CH) or tetrahydrofuran (THF), followed by Au(III) reduction coupled-adsorption. The nanomaterials were analysed using scanning transmission electron microscopy (STEM) and Fourier-transformation infrared spectroscopy (FT-IR). The catalytic reaction was carried out in a dialysis unit, where the concentration of 4-NP in the wastewater, and the concentration of separated 4-AP were monitored using UV-Vis spectroscopy. The nanocomposite membranes formed using THF effectively reduced the 4-NP and separated the resultant 4-AP. The yield of the 4-NP conversion reached 80% with a rate constant of 11.30 10-3 min-1. Based on the results, THF contributed to the formation of diffusion paths in which the 4-NP was simultaneously separated and reduced.

Published
2023
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17. Waste-Derived Caffeine for Green Synthesis of Rhenium Nanoparticles with Enhanced Catalytic Activity in the Hydrogenation of 4-Nitrophenol.

Author

Kuś, Alicja, Leśniewicz, Anna, Dzimitrowicz, Anna, Pohl, Pawel, and Cyganowski, Piotr

Subjects
COFFEE grounds, COFFEE waste, X-ray powder diffraction, COFFEE beans, CATALYTIC hydrogenation
Abstract

Yearly, thousands of tons of wasted coffee grounds are produced according to high coffee consumption. Still, after the coffee brewing, wasted coffee grounds contain some amounts of caffeine (CAF). CAF, in turn, contains multiple O and N chelating atoms in its structure. These have a potential to be reductors for complexes of metals. In this context, within the present study, a set of CAF extracts derived from coffee beans and coffee grounds were obtained and then used for the one-step reduction of ReO4− ions with no additional toxic chemicals. Within this approach, CAF was applied as a secondary, green resource for the synthesis of unique rhenium nanoparticles (ReNPs) containing Re species at 0 and +6 oxidation states. The obtained ReNPs were identified and characterized with the use of X-ray powder diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). Further, the capping and stabilization of ReNPs by CAF were verified with the aid of Fourier transformation infrared spectroscopy (FT-IR). The so-obtained "green" ReNPs were then used as a homogenous catalyst in the catalytic hydrogenation of 4-nitrophenol (4-NP). This new nanomaterial revealed a superior catalytic activity, leading to the complete reduction of 4-NP to 4-aminophenol within 40–60 min with a first-order rate constant of 0.255 min−1. [ABSTRACT FROM AUTHOR]

Published
2024
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23. The Potential of Cold Atmospheric Pressure Plasmas for the Direct Degradation of Organic Pollutants Derived from the Food Production Industry.

Author

Cyganowski, Piotr, Terefinko, Dominik, Motyka-Pomagruk, Agata, Babinska-Wensierska, Weronika, Khan, Mujahid Ameen, Klis, Tymoteusz, Sledz, Wojciech, Lojkowska, Ewa, Jamroz, Piotr, Pohl, Pawel, Caban, Magda, Magureanu, Monica, and Dzimitrowicz, Anna

Subjects
*COLD atmospheric plasmas, *PERSISTENT pollutants, *POLLUTANTS, *FOOD production, *REACTIVE nitrogen species, *ORGANIC foods, *TOXAPHENE, *ORGANIC farming
Abstract

Specialized chemicals are used for intensifying food production, including boosting meat and crop yields. Among the applied formulations, antibiotics and pesticides pose a severe threat to the natural balance of the ecosystem, as they either contribute to the development of multidrug resistance among pathogens or exhibit ecotoxic and mutagenic actions of a persistent character. Recently, cold atmospheric pressure plasmas (CAPPs) have emerged as promising technologies for degradation of these organic pollutants. CAPP-based technologies show eco-friendliness and potency for the removal of organic pollutants of diverse chemical formulas and different modes of action. For this reason, various types of CAPP-based systems are presented in this review and assessed in terms of their constructions, types of discharges, operating parameters, and efficiencies in the degradation of antibiotics and persistent organic pollutants. Additionally, the key role of reactive oxygen and nitrogen species (RONS) is highlighted. Moreover, optimization of the CAPP operating parameters seems crucial to effectively remove contaminants. Finally, the CAPP-related paths and technologies are further considered in terms of biological and environmental effects associated with the treatments, including changes in antibacterial properties and toxicity of the exposed solutions, as well as the potential of the CAPP-based strategies for limiting the spread of multidrug resistance. [ABSTRACT FROM AUTHOR]

Published
2024
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