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Fotokatalizatory i fotoelektrokatalizatory w procesach wytwarzania nadtlenku wodoru

Gańczarczyk Roman M.

Wiadomości Chemiczne

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2023

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[Z] 77, 11-12

1017--1040

EN

A significant contemporary challenge in the field of science and technology pertains to the development of innovative and sustainable methods for energy acquisition. The dynamic advancement of solar energy conversion techniques has led to the swift commercialization of photovoltaic cell technology, concomitantly creating a demand for cost-effective energy conversion and storage systems. An interesting solution to this challenge lies in the application of photocatalytic and photoelectrocatalytic synthesis to produce energy-rich molecules. One of the possible solutions under consideration in this context is hydrogen peroxide artificial photosynthesis. In recent years, several research efforts have been dedicated to the photo-assisted generation of hydrogen peroxide through oxygen reduction and water oxidation. In this brief review, the fundamental aspects related to photocatalytic and photoelectrocatalytic processes have been presented. Particular attention was paid to issues related to various groups of active photo(electro)catalysts used in the synthesis of hydrogen peroxide, and the latest trends in the molecular engineering of these compounds were highlighted.

2

Rozkład nadtlenku wodoru podczas katalitycznego epoksydowania propylenu

Lina Wang, Cheng Shen, Yingfeng Duan, Wei Du, Yagang Zhang, Wenying Li

Przemysł Chemiczny

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2023

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T. 102, nr 10

1018--1021

PL

Jako katalizator epoksydowania propylenu za pomocą nadtlenku wodoru w wodnym roztworze metanolu zastosowano sito molekularne TS-1 (krzemian tytanu). Zbadano szybkość samoistnego rozkładu nadtlenku wodoru wtemp. 30-50°C. Znaleziono optymalne warunki (temp. reakcji 43°C, stężenie nadtlenku wodoru 10,3% mas., zawartość metanolu 65% mas.). Ustalono, że rozkład nadtlenku wodoru jest reakcją pierwszego rzędu. Wyznaczono stałą szybkości tej reakcji i jej energię aktywacji.

EN

Ti silicalite mol. sieve (TS-1) was used as catalyst for propylene epoxidation with H₂O₂ in aq. MeOH soln. The H₂O₂ self-decompn. rate at 30-50°C was studied. The optimum conditions were found (reaction temp. 43°C, H₂O₂ concn. 10.3% by mass, MeOH concn. 65% by mass). The H₂O₂ selfdecompn. was the first-order reaction. Its reaction rate const. and activation energy were detd.

3

New insights into pyrite-hydrogen peroxide interactions during froth flotation : experimental and DFT study

Cao Qinbo, Yan Wenchao, Wen Shuming, Liu Dianwen, Li Yanjun

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 1

art. no. 157409

EN

Hydrogen peroxide (H2O2) is an efficient depressant for pyrite (FeS2) flotation. However, the depressing mechanism of H2O2 is not fully understood. In this paper, the depressing capacity of H2O2 for pyrite was examined by flotation tests. Results revealed that pyrite flotation could be inhibited by H2O2 at pH 6.4. The pyrite powder in H2O2 solution enhanced the release of O2 from H2O2. However, the O2 concentration in the solution was less than that of H2O2; thus, H2O2 is the major oxidant in the solution. Moreover, density functional theory calculations were performed to study the interactions between H2O2 and hydrated pyrite (100) surface. The H2O2 molecule tended to react with the pyrite surface to generate one S=O bond and an H2O molecule. The possible binding models of O2 molecules on the pyrite (100) surface were also studied for comparison. The O2 dissociation on the pyrite surface was more favorable than the adsorption of O2 as a whole. In addition, the orbital interaction in the S=O bond raised from the reaction of H2O2/O2 with the pyrite surface was also investigated by the density states analysis. These results provide some insights into the oxidizing effect of H2O2 in pyrite flotation.

4

A new environmentally friendly chemical mechanical polishing method applied for surface finishing Ti-6Al-4V alloy

Quang Nguyen Minh, Quan Nguyen Ngoc, Mai Nguyen Trong, Thanh Le Thi Phuong, Tung Nguyen Tien, Tan Tran Ngoc, Hai Ha Thanh, Trinh Nguyen Duy

Journal of Machine Engineering

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2023

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Vol. 23, No. 4

64--76

EN

A new eco-friendly slurry has been developed for the chemical mechanical polishing process with a solution of malic acid, deionized water, and an oxidizing agent hydrogen peroxide (H2O2). The surface quality of Ti-6Al-4V workpieces with the proposed chemical mechanical polishing slurry with optimal parameters include oxidizers (H2O2), colloidal (SiO2) slurry, and deionized water by weight 8%, 45%, and 47% respectively, the pH concentration is adjusted 4 through the malic acid content present in the slurry. Experimental results obtained with the proposed chemical mechanical polishing method show a more improved surface quality than previous studies when applying for polishing Ti-6Al-4V alloy. The developed chemical mechanical polishing method's polishing results under optimal conditions obtain an ultra-fine surface quality with Ra = 0.696 nm over a measuring area of 53×70 μm2. X-ray photoelectron (XPS) and electrochemical measurements were used to study the chemical reaction mechanisms in the proposed chemical mechanical polishing process. The chemical mechanical polishing processes for the surface of the Ti-6Al-4V alloy workpiece with the H2O2 oxidizing agent showed high suitability with the reactants formed on the surface such as Ti, V, and Al oxide. With the proposed oxidant and the established chemical mechanical polishing slurry, the feasibility and surface quality of the super smooth Ti-6Al-4V workpiece formed after polishing were demonstrated. The established chemical mechanical polishing method shows high applicability in environmental protection and Ti-6Al-4V alloy ultra-precision machining industries.

5

Wykorzystanie gazowego nadtlenku wodoru do biodekontaminacji materiałów z zanieczyszczeń mikrobiologicznych

Furtak Elwira, Cichocka Wioletta, Kisielińska-Kot Edyta

Przemysł Chemiczny

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2021

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T. 100, nr 3

240--245

PL

Sterylizacja nadtlenkiem wodoru jest bardzo skuteczną metodą pozbywania się mikroorganizmów oraz ich form przetrwalnikowych z zanieczyszczonych powierzchni. Zbadano skuteczność procesu sterylizacji różnych materiałów skażonych zawiesiną grzybów pleśniowych oraz wpływ nadtlenku wodoru na fizykomechaniczne właściwości tych materiałów. Zastosowanie nadtlenku wodoru w formie gazowej dało zadowalające efekty w usuwaniu mikroorganizmów, nie powodując zmian właściwości sterylizowanego materiału.

EN

Many materials (filtration paper, uniform textile, leather) were contaminated with mould spores and then sterilized with H₂O₂ vapors at 40°C for 5–60 min. Full removal of spores was achieved. No changes of color, hydrophobicity and mechanical strength were obsd.

6

Nadtlenek wodoru : metoda oznaczania w powietrzu na stanowiskach pracy metodą spektrofotometryczną

Mysur Wioletta, Kucharska Nadia, Bonczarowska Marzena, Brzeźnicki Sławomir

Podstawy i Metody Oceny Środowiska Pracy

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2021

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Nr 3 (109)

161-171

PL

Nadtlenek wodoru w temperaturze pokojowej występuje w postaci bezbarwnej, przejrzystej cieczy, o słabym zapachu ozonu. Nadtlenek wodoru jest wykorzystywany jako wybielacz w przemyśle papierniczym, spożywczym i kosmetycznym oraz do produkcji paliwa rakietowego. Właściwości utleniające nadtlenku wodoru są wykorzystywane w procesie oczyszczania ścieków oraz w medycynie do odkażania ran (woda utleniona). W chemii analitycznej związek ten wykorzystywany jest w oznaczeniach śladowych ilości metali. Szkodliwe działanie nadtlenku wodoru polega na działaniu drażniącym na skórę, błony śluzowe oczu i górnych dróg oddechowych. Celem prac badawczych było opracowanie i walidacja metody oznaczania nadtlenku wodoru w powietrzu na stanowiskach pracy. Opracowana metoda oznaczania polega na pochłanianiu nadtlenku wodoru w wodzie, a następnie na spektrofotometrycznym oznaczeniu kompleksu oranżu ksylenolowego z utlenionymi przez nadtlenek wodoru jonami żelaza (Fe III). Do badań wykorzystano spektro¬fotometr UNICAM umożliwiający wykonanie oznaczeń przy długości fali 560 nm. Opracowana metoda jest liniowa w zakresie stężeń 0,02 ÷ 0,4 μg/ml, co odpowiada zakresowi 0,04 ÷ 0,8 mg/m³ dla próbki powietrza o objętości 10 l. Opracowana metoda umożliwia oznaczanie nadtlenku wodoru w powietrzu na stanowiskach pracy w obecności substancji współwystępujących. Metoda charakteryzuje się dobrą precyzją i dokładnością i spełnia wymagania normy PN-EN 482 dla procedur dotyczących oznaczania czynników chemicznych. Opracowana metoda oznaczania nadtlenku wodoru w powietrzu na stanowiskach pracy została zapisana w postaci procedury analitycznej, którą zamieszczono w załączniku. Zakres tematyczny artykułu obejmuje zagadnienia zdrowia oraz bezpieczeństwa i higieny środowiska pracy będące przedmiotem badań z zakresu nauk o zdrowiu oraz inżynierii środowiska.

EN

Hydrogen peroxide at room temperature is a colourless clear liquid with weak ozone like odour. It is used as a bleach in paper, food and cosmetics industry and in rocket fuel production. It is also used in waste water and waste gas treatment and as a disinfectant in wounds treatment. In analytical chemistry, hydrogen peroxide is used to determine trace amounts of metals. Hydrogen peroxide may cause irritation of eyes, skin, and respiratory tract. The goal of this research was to develop and validate a method for determining hydrogen peroxide in workplace air. Developed method is based on the collection of hydrogen peroxide with water filled bubbler and spectrophotometric determination of xylenol orange and ferrum (III) ions complex. Developed method is linear in the concentration range of 0.2-4.0 µg/ml, which corresponds to the range of 0.04-0.8 mg/m³ for 10-L air sample. The analytical method described in this paper makes it possible to determine hydrogen peroxide in workplace air in the presence of other substances. The method is precise, accurate and it meets the criteria for procedures for determining chemical agents listed in Standard No. PN-EN 482. The developed method of determining hydrogen peroxide in workplace air has been recorded as an analytical procedure (see Appendix). This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.

7

Degradation of toluene using UV/hydrogen peroxide process

Cai Shaokang, Sun Yue, Gao Canzhu, Li Pengfei, Cheng Zhongfa

Environment Protection Engineering

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2021

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Vol. 47, nr 1

5-15

EN

Toluene in wastewater is volatile and difficult to degrade, and the longer it stays in the water, the higher is the risk. An advanced oxidation process (AOPs) has been used to degrade toluene rapidly and efficiently in wastewater by using ultraviolet light and hydrogen peroxide. Toluene in solution (initial concentration – 180 mg/dm3) with hydrogen peroxide (H2O2 dose – 2022 mg/dm3) was almost decomposed within 150 min. pH as well as the presence of various ions in waste water did not affect the degradation process. However, under strongly acidic conditions (pH less than 3), the chloride ions reduced the degradation efficiency of toluene. Based on the UV spectrophotometer and GC-MS analyses, the degradation pathways were observed: first, the methyl group was oxidized leading to the generation of benzoic acid, the benzene ring was subsequently opened by the action of hydroxyl radical, followed by the gradual decomposition of the intermediate products into small molecules such as water and carbon dioxide.

8

Modification of the Detonation Parameters of Mining Explosives Containing Hydrogen Peroxide and Aluminium Powder

Paszula Józef, Maranda Andrzej, Nikolczuk Karolina, Giercuszkiewicz Agnieszka

Central European Journal of Energetic Materials

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2021

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Vol. 18, no. 4

477--491

EN

Presently, due to rising environmental consciousness, numerous actions are being taken to prevent devastation of the natural environment. If explosive mixtures are manufactured in an insufficiently controlled manner, they contain too much ammonium nitrate and generate nitrogen oxides (NOx), which are both harmful for living organism and responsible for negative weather phenomena. However, the products from decomposition of hydrogen peroxide are only oxygen and hydrogen, which are both environmentally friendly. This paper presents the results of research on the impact of two types of aluminium powder on the detonation parameters of mining explosives containing hydrogen peroxide 60% as an oxidiser. The detonation velocities were measured by means of short circuit sensors. Direct measurement of the blast wave overpressure was performed with piezoelectric sensors and the positive phase impulse was analyzed. Measurement of the explosive strength was made by the ballistic pendulum method for 10 g samples. The results of these experiments showed that the addition of both types of aluminium, as well as their content in the explosive mixture, have a significant impact on all of the measured parameters.

9

Thermodynamics and kinetics of thermal deactivation of catalase Aspergillus niger

Miłek Justyna

Polish Journal of Chemical Technology

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2020

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Vol. 22, nr 2

67--72

EN

The thermal stability of enzyme-based biosensors is crucial in economic feasibility. In this study, thermal deactivation profiles of catalase Aspergillus niger were obtained at different temperatures in the range of 35° C to 70° C. It has been shown that the thermal deactivation of catalase Aspergillus niger follows the first-order model. The half-life time t 1/2 of catalase Aspergillus niger at pH 7.0 and the temperature of 35° C and 70° C were 197 h and 1.3 h respectively. Additionally, t 1/2 of catalase Aspergillus niger at the temperature of 5° C was calculated 58 months. Thermodynamic parameters the change in enthalpy ΔH*, the change in entropy ΔS* and the change Gibbs free energy ΔG* for the deactivation of catalase at different temperatures in the range of 35° C to 70° C were estimated. Catalase Aspergillus niger is predisposed to be used in biosensors by thermodynamics parameters obtained.

10

Seasonal variability of antibiotic resistance and biodiversity of tap water bacteria in Wrocław, Poland

Siedlecka Agata, Wolf-Baca Mirela, Piekarska Katarzyna

Environment Protection Engineering

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2020

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Vol. 46, nr 2

93--109

EN

Antibiotic resistance of bacteria has become a worldwide problem. Drinking water distribution systems (DWDSs) can be regarded as reservoirs of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs). This study aims to provide a preliminary evaluation of seasonal changes in the occurrence of ARB and ARGs in Wrocław tap water samples. It also investigates the biodiversity of bacterial communities dwelling in Wrocław DWDS and compares them with worldwide literature reports. Third generation cephalosporins resistant bacteria were present in each season, with relative abundances reaching from 40.46% in spring to 99.86% in summer. β-lactams and tetracyclines resistant bacteria were present only in spring and autumn samples, with relative abundances reaching from 0.51% to 3.80%. Relative abundances of ARB fluctuated across the year, and no season-dependent trend was found. This suggests that other factors influenced the resistance phenomenon in Wrocław tap water. The investigated resistomes were represented only by several ARGs (qnrB, tetW, ermB,qacEΔ1). Class 1 integrons gene intI1 was also detected. Biodiversity of bacteria collected from large amounts of tap water was similar to that reported previously for Wrocław and worldwide DWDSs, with a prevalence of Proteobacteria, followed by Actinobacteria, Cyanobacteria, and Firmicutes.

11

Effects of plant extracts and disinfectant Huva-San TR 50 on the quality of carrot (Daucus carota L.) seeds

Górski Romuald, Szopińska Dorota, Dorna Hanna, Rosińska Agnieszka, Stefańska Zuzanna, Lisiecka Jolanta

Ecological Chemistry and Engineering. S

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2020

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Vol. 27, nr 4

617--628

EN

The aim of the study was to determine the effect of Aloe vera (L.) Burm.f. (Aloe) and Morinda citrifolia L. (Indian mulberry) plant extracts and disinfectant Huva-San TR 50 (hydrogen peroxide stabilized with silver ions) on carrot seed quality. The seeds of two carrot cultivars Amsterdam (sample I) and Berlikumer 2 (sample II), were soaked in solutions of Aloe and Indian mulberry extracts and Huva-San TR 50 at concentrations of 0.025 %, 0.05 % and 0.1 % for 30 min. Untreated seeds and seeds soaked in distilled water for 30 min were used as controls. Seed germination was assessed after 7 and 14 days of incubation. The speed and uniformity of seed germination (vigour) were evaluated. Mycological analysis was performed using a deep-freeze blotter test. Sample I was characterized by lower germination at the first and the final counts than sample II and higher seed infestation with Alternaria radicina. Treating seeds of sample I with Morinda citrifolia plant extract at concentrations of 0.025 and 0.05 % reduced their infestation with Alternaria alternata and A. radicina, increased germination at the first and the final counts, and did not affect seed vigour. The effects of Aloe extract and disinfectant Huva-San TR 50 on seed quality parameters varied depending on their concentration. Hence, further studies are necessary to establish the optimal conditions for carrot seed treatment.

12

The effect of electrolyte composition on the plasma electrolyte oxidation and phase composition of oxide ceramic coatings formed on 2024 aluminium alloy

Posuvailo V. M., Kulyk V. V., Duriagina Z. A., Koval’chuck I. V., Student M. M., Vasyliv B. D.

Archives of Materials Science and Engineering

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2020

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Vol. 105, nr 2

49--55

EN

Purpose: Purpose of this work is to analyse the process of synthesis of oxide ceramic coatings in plasma electrolytes on 2024 aluminium alloy and to form an electrolyte which allows to reduce energy consumption for the coating formation. Design/methodology/approach: The oxide ceramic coatings were synthesized on 2024 aluminium alloy. The coatings were formed by the alternate application of anode and cathode pulses to the sample. X-ray diffraction analysis of coatings was performed on a DRON-3.0 X-ray diffractometer using CuKa radiation. The thickness of the coatings was determined using a CHY TG-05 thickness gauge. The porosity of the coatings was investigated by analysing the micrographs of the plasma electrolyte oxidation (PEO) coatings obtained on a scanning electron microscope at x500 magnification using the image processing technique. Findings: The electrolyte with 5 g/l H2O2 additive have been elaborated as an optimal composition for synthesis of a coating with an increased content of corundum (a-Al2O3) as compared to a coating synthesized in the same mode in the 3KOH+2Na2SiO3 electrolyte without H2O2. This synthesis mode allows obtaining a coating with a high corundum content at low energy consumption. Research limitations/implications: For further optimization of the synthesis modes, it is necessary to analyse the influence of the phase composition and porosity of the obtained oxide ceramic coatings on their microhardness, wear resistance, and corrosion resistance. Practical implications: Based on the developed modes of synthesis of the coatings, it will be possible to obtain wear and corrosion resistant oxide ceramic coatings with predetermined functional properties and to reduce energy consumption for their formation. Originality/value: Methods for accelerating the formation of coatings have been proposed and tested, in particular, by adding various amounts of hydrogen peroxide to the electrolyte. The content of oxides in the obtained coatings, in particular, their ratios at various concentrations of hydrogen peroxide in the electrolyte, were determined by X-ray phase analysis. The modes of synthesis of the coatings were developed which allow obtaining a continuous coating without cracks with simultaneous decreasing porosity from 4.32% to 3.55-3.53%.

13

Immobilization of permeabilized cells of baker’s yeast for decomposition of H2O2 by catalase

Trawczyńska Ilona

Polish Journal of Chemical Technology

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2019

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Vol. 21, nr 2

59--63

EN

Permeabilization is one of the effective tools, used to increase the accessibility of intracellular enzymes. Immobilization is one of the best approaches to reuse the enzyme. Present investigation use both techniques to obtain a biocatalyst with high catalase activity. At the beginning the isopropyl alcohol was used to permeabilize cells of baker’s yeast in order to maximize the catalase activity within the treated cells. Afterwards the permeabilized cells were immobilized in calcium alginate beads and this biocatalyst was used for the degradation of hydrogen peroxide to oxygen and water. The optimal sodium alginate concentration and cell mass concentration for immobilization process were determined. The temperature and pH for maximum decomposition of hydrogen peroxide were assigned and are 20°C and 7 respectively. Prepared biocatalyst allowed 3.35-times faster decomposition as compared to alginate beads with non permeabilized cells. The immobilized biocatalyst lost ca. 30% activity after ten cycles of repeated use in batch operations. Each cycles duration was 10 minutes. Permeabilization and subsequent immobilization of the yeast cells allowed them to be transformed into biocatalysts with an enhanced catalase activity, which can be successfully used to decompose hydrogen peroxide.

14

Mechanism and leaching kinetics of molybdenite concentrate in a hydrogen peroxide-acid system

Aracena Alvaro, Azocar Alan, Ibáñez Juan Patricio, Jerez Oscar

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 1

140--152

EN

The mechanism and leaching kinetics of a molybdenite concentrate in a H2O2-H2SO4 system were studied. The experimental work was performed in a batch reactor equipped with a condenser, a mechanical agitator and a temperature control system. The effects of the temperature, H2O2 and H2SO4 concentrations, particle size, liquid/solid ratio and agitation speed on the Mo recovery were investigated. The thermodynamic results showed that the leaching mechanism it was governed by several intermediate reactions; however, the influences of sulfuric acid and passivation were not observed in the reaction. The most predominant experimental result was the maximum Mo recovery of 81.3% by leaching 64 μm particles at 333 K (60 °C) for 5400 s (90 min). The molybdenum recovery was generally enhanced by increasing the H2O2 and H2SO4 concentrations. However, at H2SO4 concentrations higher than 1.0 mol/dm3, the Mo recovery decreased. Although the agitation speed affected the Mo recovery considerably, high recoveries could be still obtained without mixing. The experimental results and XRD analysis confirmed the reaction mechanisms. The leaching kinetics were analyzed using a shrinking core model in which the rate was controlled by diffusion through a porous layer with radius ro. The reaction rate orders were 1.0 and 0.2 for the H2O2 and H2SO4 concentrations, respectively, and the rate was inversely proportional to the square of the initial particle radius. The calculated activation energy was 75.2 kJ/mol in the temperature range of 278-333 K (5-60 °C).

15

Możliwości modyfikacji procesu Fentona w aspekcie skuteczności utleniania trudno biodegradowalnych zanieczyszczeń organicznych

Janda Anna, Marcinkowski Tadeusz

Ochrona Środowiska

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2019

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Vol. 41, nr 1

47--53

PL

Mechanizm procesu Fentona pozwala na usuwanie trudno biodegradowalnych związków organicznych z wody, ścieków, gleby oraz osadów. Klasyczna reakcja Fentona zachodzi w środowisku kwasowym, które zapewnia skuteczne tworzenie rodników hydroksylowych. Temperatura i pH środowiska reakcji są najważniejszymi parametrami decydującymi o dynamice przebiegu procesu Fentona oraz o chemizmie zachodzących reakcji. Środowisko kwasowe reakcji Fentona pozwala na dysocjację źródła tlenu do rodników, jednak z drugiej strony jest przyczyną zbyt szybkiego rozkładu niestabilnego H2O2 i powoduje wzrost temperatury środowiska reakcji. Takie warunki procesu są obarczone wysokim prawdopodobieństwem utraty potencjału utleniającego w wyniku reakcji konkurencyjnych. Z tego względu możliwe są różne modyfikacje klasycznego procesu Fentona, takie jak stosowanie alternatywnego źródła tlenu (CaO2), innej formy katalizatora reakcji i/lub środków chelatujących oraz wykorzystanie promieniowania nadfioletowego. Modyfikacje te pozwalają na zwiększenie wartości pH reakcji, bez znaczącej utraty rodników hydroksylowych. Doświadczenia badawcze wskazują, że stopień usunięcia zanieczyszczeń organicznych, w zależności od zastosowanych konfiguracji procesu Fentona i dawek reagentów, może sięgać niemal 100%.

EN

The Fenton mechanism allows for removal of difficult-to-degrade organic compounds from water, wastewater, soil, and sediments. The classic Fenton reaction takes place in acidic pH, which ensures effective hydroxyl radicals formation. Temperature and pH of the reaction environment are the key parameters affecting the Fenton process and chemistry of the reactions involved. The acidic conditions allow for dissociation of the oxygen source into radicals. On the other hand, however, they cause rapid decomposition of labile H2O2, leading to an increase in temperature of the reaction environment. Under these circumstances, there is a high likelihood of losing the oxidative potential through competitive reactions. For this reason, various modifications of the classic Fenton reaction are applied, including the use of an alternative source of oxygen (CaO2) or a different form of the reaction catalyst and/or chelating agents as well as UV radiation application. These modifications allow for an increase in pH without a significant loss of hydroxyl radicals. The research experience indicates that the degree of contaminants removal may reach even 100%, depending on the applied Fenton process configurations and reagent doses.

16

Hydrogen peroxide (H2O2) : a review of its use in homemade explosives

Rarata Grzegorz, Vahčič Mitja, Anderson David, Berglund Michael, Kyprianou Dimitris, Emma Giovanni, Diaconu Gabriela

Materiały Wysokoenergetyczne

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2019

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T. 11(2)

5--13

EN

This article presents an overview of hydrogen peroxide and its use in the illicit production of homemade explosives. Hydrogen peroxide is used extensively around the world in many industries, including aerospace. It is also used as the main ingredient in some household cleaning products. However, it has been illicitly used to create both primary and secondary homemade explosives in recent numerous terrorist attacks across Europe. In this article, we describe the historical background and the characteristics of the substance, the aspects concerning its manufacture and present-day use as a main explosive component or direct chemical precursor of homemade explosives, and the options for detection.

PL

W artykule zostały omówione najważniejsze, improwizowane materiały wybuchowe, których chemicznym prekursorem jest nadtlenek wodoru. Roztwory nadtlenku wodoru są intensywnie używane w wielu dziedzinach życia, począwszy od przemysłu kosmicznego, a skończywszy na wybielaczach stosowanych w gospodarstwach domowych. Niestety, medium to zostało także wykorzystane do uzyskiwania nielegalnych materiałów wybuchowych, których użyto miedzy innymi w atakach terrorystycznych w Europie Zachodniej kilka lat temu. Dlatego też w prezentowanym tutaj przeglądzie przedstawiamy historyczny rys dotyczący tego interesującego związku chemicznego, ale także aspekty związane z jego użyciem jako prekursora nielegalnych materiałów wybuchowych. Opisane zostały również podstawowe sposoby detekcji tychże związków.

17

Explosive potential of energetic mixtures based on hydrogen peroxide

Papliński Andrzej

Materiały Wysokoenergetyczne

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2019

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T. 11(2)

14--20

EN

The explosion and detonation of energetic compositions based on hydrogen peroxide (H2O2, HP) is investigated. Fuels with different oxygen balance were considered in the mixture with HP/ methanol, ethylene glycol, glycerine ethanol. Detonation performance at a wide range of reciprocal HP/fuel concentrations was examined. Heats of explosion at constant volume, detonation velocity, as well as volume of gaseous products of reaction were estimated in thermochemical evaluations. The modification of explosive properties of the high-energetic CHNO material by addition of hydrogen peroxide, was also investigated. To represent CHNO explosives, nitromethane was considered. In the performed analysis, aqueous solutions of hydrogen peroxide were considered with the aim of obtaining the appropriate fuel/HP/water ratios to predict potential explosive compositions.

PL

W pracy przedstawiona została analiza parametrów wybuchu i detonacji mieszanin energetycznych zawierających nadtlenek wodoru (H2O2, HP). Jako dodatki rozważane były niewybuchowe materiały o ujemnym bilansie tlenowym. Rozpatrzone zostały dwie grupy paliw, metanol, glikol etylenowy i gliceryna o umiarkowanie negatywnym bilansie tlenowym oraz alkohol etylowy o zdecydowanie ujemnym bilansie tlenowym. Wybuchowe i detonacyjne właściwości badanych mieszanin paliwo/ HP badane były w szerokim zakresie wzajemnych zmian stężenia składników. Ciepło wybuchu w stałej objętości, prędkość detonacji oraz objętość gazowych produktów przemiany określane były za pomocą obliczeń termochemicznych. Rozpatrzony został również wpływ dodatku HP do materiału wybuchowego z grupy CHNO. Jako przykładowy materiał z grupy CHNO rozpatrzony został nitrometan. Przyjmowano zastosowanie HP w roztworze wodnym. Przedmiotem prowadzonych analiz było określenie zakresów stężeń, dla których mieszaniny paliwo/HP/woda będą odpowiednie do stosowania w ładunkach wybuchowych.

18

Physiological and Biochemical Changes Induced by UV-B Radiation in Rosemary Plants Grown Under Salinity Stress

Moghaddam Abolghasem Hamidi, Arouiee Hossein, Moshtaghi Nasrin, Azizi Majid, Shoor Mahmoud, Sefidkon Fatemeh

Journal of Ecological Engineering

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2019

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Vol. 20, nr 5

217--228

EN

Plants are exposed to solar ultraviolet radiation due to use of sunlight for photosynthesis. Additionally, salinity in soil or water influences the plant productivity and quality considerably. Moreover, when plants are simultaneously exposed to multiple stresses, one form of stress can affect the response to other stress. Particularly, it has been shown that they can benefit from dual tolerance as salinity and UV-B radiation are applied together. In order to understand the effects of UV-B radiation and salinity stress on some physiological and biochemical parameters, one-year-old cuttings of rosemary plants were grown under different levels of ultraviolet B radiation (0, 4.32 and 6.05 kJ m-2 d-1) and salinity stress (control, 50, 100 and 150 mM NaCl). The results showed that 4.32 kJ m-2 d-1 UV-B treatment significantly increased plant biomass up to 17.9% as compared to control. However, by increasing salinity to 150 mM, plant biomass significantly decreased up to 18.1%, as compared to control. Regardless of UV-B treatments, plants, grown under 100 mM salinity stress, had produced 2.8 times higher total phenolic compounds (TPC) and also have greater antioxidant activity (33.1%) in comparison to control. Both treatments, enhanced UV-B radiation and salinity stress, significantly increased the concentration of proline, hydrogen peroxide (H2O2) and malondealdehyde (MDA). In relation of total soluble sugar (TSS) and ion content, both treatments acted in an opposing manner. In turn, the enhanced UV-B radiation decreased concentration of TSS and the Na+ content in leaves, salinity stress increased the concentration of TSS, as well as the Na+ content in leaves and root. The plants grown under 150 mM salinity level accumulated 5.32 and 2.83 times higher Na+ ions in leaves and roots, respectively, than control. In addition, salinity significantly decreased the relative water content (RWC), photosynthetic pigments and K+ content in leaves and roots. The interaction between UV-B irradiation and salinity showed that the UV-B radiation improved the K+ content in leaves, RWC and membrane stability and consequently resulted in a better tolerance of rosemary to salinity.

19

Measurements of the VOD of Selected Mining Explosives and Novel “Green Explosives” Using the Continuous Method

Nikolczuk Karolina, Maranda Andrzej, Mertuszka Piotr, Fuławka Krzysztof, Wilk Zenon, Koślik Piotr

Central European Journal of Energetic Materials

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2019

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Vol. 16, no. 3

468--481

EN

Explosive velocity, also known as detonation velocity or velocity of detonation (VOD), is one of the most important and basic parameters describing the properties of explosives. This work presents the VOD results of three different explosives. Two of the explosives were ammonium nitrate-based (straight emulsion and Heavy ANFO). The third explosive was based on hydrogen peroxide (HP). The aim of the experiments was to compare the VOD of the HP-based against the VOD of the ammonium nitrate-based explosives. The final conclusions and results of this preliminary work and the analysis of available literature show that HP-based explosives, so called “green explosives”, have the potential to successfully replace ammonium nitrate-based explosives in some applications. The results of this work will be used to develop production technology for new HP-based explosives and to find their possible applications, considering their environmentally friendly character (this novel formulation of explosive eliminates post-blast nitrogen oxide fumes (NOx), as a direct product of the detonation process). During the burning reaction, nitrogen oxides (NO, NO2) are produced as a result of the use of bulk ammonium nitrate-based commercial explosives. Exposure to these toxic gases can have negative effects on the health and safety of personnel and the surrounding environment. The results obtained for the new emulsion explosives allow them to be used extensively in the industry as a competitive product on the market.

20

Increasingly safe, high-energy propulsion system for nano-satellites

Sabadosh L., Larkov S., Kravchenko O., Sereda V.

Transactions on Aerospace Research

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2018

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Nr 4 (253)

49--56

EN

Numerous attempts have been undertaken to develop propulsion systems for nanosatellite-type spacecrafts to enable their maneuvering in orbits. One of the potentially viable chemical propellant propulsion systems is a hybrid system. The present paper studies propellant composition variants with the metal hydride as fuel that can be chosen for a nano-satellite hybrid propulsion system. It defines key requirements for chemical propellant nano-satellite propulsion systems, and specifies potential propellant pairs based on a compact metal hydride. The study describes basic technical characteristics of a 1U CubeSat propulsion system.

PL

Podjęto wiele prób opracowania układów napędowych dla statku kosmicznego z klasy nanosatelitów, aby zapewnić możliwość manewrowania na orbicie. W szczególności jednym z obiecujących typów układów napędowych dla paliwa chemicznego jest układ hybrydowy. W artykule zaproponowano warianty kompozycji pędnych z wodorkiem metalu jako paliwem, które można wybrać dla hybrydowego napędu nanosatelitarnego. Zaprezentowano główne wymagania dotyczące układów napędowych dla paliwa chemicznego do nanosatelitów, i przedstawiono potencjalne pary propelentów oparte na zwartym wodorku metalu jako paliwie. Określono główne właściwości techniczne układu napędowego dla satelitów klasy CubeSat 1U.