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1

Review of the Methods for Selective Nitration of Toluene

Nastała Andrzej, Maksimowski Paweł

Central European Journal of Energetic Materials

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2023

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Vol. 20, no. 2

97--113

EN

A solution to the problems encountered with the treatment of wastewater during the industrial production of TNT could be the use of the mixture of nitrotoluenes (NTs) with no or a smaller amount of the meta-NT compared to the mixture resulting from conventional mononitration. This can be achieved by selective nitration of toluene with a nitration mixture which is more selective than conventional nitrating mixtures. This paper presents a review of the literature related to the methods for selective nitration of toluene using the following nitrating agents: nitric(V) acid, acetyl nitrate(V), nitrogen(V) oxide and others.

2

Selective Nitration of Toluene using Nitrogen(V) Oxide in Dichloromethane and Catalysts

Maksimowski Paweł, Nastała Andrzej, Tomaszewski Waldemar

Central European Journal of Energetic Materials

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2022

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Vol. 19, no. 4

424--437

EN

A series of toluene nitration reactions was carried out using a nitrogen(V) oxide (N₂O₅)solution in dichloromethane (CH₂Cl₂), with and without the addition of solid catalysts. N₂O₅ in CH₂Cl₂ was found to be a more active and selective mixture compared to 100% nitric acid and a mixture of nitric acid(V) in CH₂Cl₂. Temperature has a significant effect on the composition of the products of nitration of toluene with N₂O₅ in CH₂Cl₂; as the reaction temperature was decreased, the amount of meta-nitrotoluene decreased to approx. 1-1.2%, at a nitration temperature below -40 °C. The use of molecular sieves with toluene adsorption resulted in a quite powerful para effect, demonstrated by a significant increase in the amount of the para isomer, while reducing the ortho- and meta-isomers. The most pertinent effect was obtained when using 13X molecular sieves. In addition to improving the selectivity, the use of molecular sieves also leads to a higher degree of nitration of toluene (toluene/N₂O₅ = 1:1) due to the resulting nitric acid being absorbed by the pores of the molecular sieve.

3

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.

4

The use of surfactant from the Tween group in toluene biofiltration

Miller Urszula, Sówka Izabela, Adamiak Waldemar

Archives of Environmental Protection

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2020

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Vol. 46, no. 2

53--57

EN

Due to the lower energy consumption and waste production compared to traditional methods, the environmental bioremediation methods based on natural processes have been gradually becoming more prevalent in environmental engineering. Biological methods are used in waste management, wastewater treatment, gas treatment or soil remediation. For the low solubility of some pollutants and lower bioavailability, the use of biological methods may be hampered. This problem might be mitigated with the use of surfactants. This paper presents the results of studies regarding the effect of dosing a selected surfactant from the Tween group (Tween 20) on the efficiency of toluene elimination from the air by biofiltration. The obtained maximum biofiltration rate was 21.2 g/m3/h and 19.8 g/m3/h for the control bed and for the bed to which the Tween 20 solution was dosed, respectively. The effect of Tween was neutral (the effectiveness of toluene removal was insignificantly comparable to the effectiveness of the control series), it did not affect the effectiveness or limited the development of the biofilter microflora.

5

Activated carbon adsorption behaviour of toluene at various temperatures and relative humidity

Görgülü Adnan, Yağli Hüseyin, Koç Yildiz, Koç Ali, Baltacioğlu Ertuğrul

Environment Protection Engineering

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2019

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Vol. 45, nr 1

111--126

EN

Filtration plays a major role in managing the rapid increase of environmental pollution and deterioration of atmospheric air quality. One of the most damaging noxious gases in the atmosphere is toluene, which is a common gas that appears in crude oil and is used in various production processes. The adsorption behaviour of activated carbon was examined in dependence of the concentration, temperature and relative humidity. The results showed that increasing air temperature decreased the time to reach the maximum saturation ratio, which occurred due to the increasing pore diffusion coefficient and pore diffusion rate.

6

Laboratoryjny biofiltr strużkowy do oczyszczania powietrza z lotnych związków organicznych o charakterze odorowym

Rybarczyk Piotr, Gospodarek Milena, Szulczyński Bartosz, Gębicki Jacek, Namieśnik Jacek

Aparatura Badawcza i Dydaktyczna

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2019

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T. 24, nr 1

24--30

PL

W pracy przedstawiono wyniki badań doświadczalnych procesu dezodoryzacji powietrza zanieczyszczonego parami toluenu w biofiltrze ze złożem zraszanym (tj. w biofiltrze strużkowym). Zaproponowano układ badawczy do procesu biofiltracji, oparty na bioreaktorze dwusekcyjnym, wypełnionym ceramicznymi pierścieniami Raschiga. Złoże biofiltra zaszczepiono drobnoustrojami z rodzaju Candida. Jako ciecz zraszającą stosowano wodny roztwór soli mineralnych. Zbadano i porównano skuteczność usuwania toluenu z mieszaniny z powietrzem, stosując ciecz zraszającą bez dodatku i z dodatkiem dodecylosiarczanu sodowego. Stwierdzono, że dodatek związku powierzchniowo czynnego powoduje wzrost stopnia usunięcia toluenu w procesie biofiltracji. Wskazano, że proponowane stanowisko może być z powodzeniem stosowane podczas laboratoryjnych badań procesu biofiltracji, zapewniając stabilność pracy układu oraz ograniczenie problemów technicznych związanych z nadmiernym wzrostem biomasy w złożu biofiltra.

EN

The paper presents the results of experimental investigations of the deodorization process of air contaminated with toluene vapors in a trickled-bed biofilter (i.e. biotrickling filter). A laboratory set-up for biofiltration process was proposed, based on a two-section bioreactor filled with Raschig ceramic rings. The biofilter bed was inoculated with microorganisms from the Candida species. Aqueous solution of mineral salts was used as the trickling liquid. The effectiveness of toluene removal from its mixture with air was investigated and compared using a trickling liquid without addition and with the addition of sodium dodecyl sulphate. It has been found that the addition of a surfactant increases the degree of toluene removal in the biofiltration process. It was pointed out that the proposed set-up can be successfully applied during laboratory investigations of the biofiltration process, ensuring system stability and reducing technical problems related to excessive biomass growth in the biofilter bed.

7

Ocena możliwości zastosowania procesu zestalania chemicznego do unieszkodliwiania gleby zanieczyszczonej toluenem

Banaszkiewicz K. P., Pasiecznik I.

Ochrona Środowiska

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2017

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Vol. 39, nr 3

41--46

EN

Chemical solidification is an established technology used in treatment of inorganic wastes contaminated mainly with trace metals (Cd, Cu, Zn, Ni, Pb). During this process, metal ions are chemically bound to hydration products of cement. In case of organic compounds, particularly volatile organic compounds (VOCs), the solidification technology has some limitations. Volatilization of VOCs during mechanical mixing of individual components of the binding mixture is a major problem. With this in mind, applicability of the technology for treatment of sandy soil contaminated with toluene was assessed in laboratory tests. Three binding (solidifying) Portland cementbased (CEM I 42.5 R) formulations, additionally supplemented with diatomaceous earth and textile fibers of high waste-rubber content were tested for soil solidification. These additional components acted as adsorbents to reduce the toluene evaporation. In the course of treatment, emission of all the gaseous contaminants was monitored. Influence of the binding (solidifying) mixture composition on toluene emission was evaluated based on the momentary toluene concentrations monitored above the surface of the reactive mixture using flame-ionization detector. The research results confirmed beneficial effect of hermetization of the contaminated soil using Portland cement. Introduction of cement equivalent to 50% of the soil weight resulted in the reduction of total toluene emission by over 26%. The cement-based mixtures containing diatomaceous earth or textile fibers gave higher results (27–45%).

PL

Stabilizacja/zestalanie jest powszechnie stosowanym procesem do unieszkodliwiania odpadów mineralnych, głównie zanieczyszczonych metalami śladowymi. W procesie tym jony metali są chemicznie wiązane z produktami hydratacji cementu. W przypadku zanieczyszczeń organicznych, w szczególności lotnych związków organicznych, technologia stabilizacji/zestalania ma pewne ograniczenia. Największy problem stanowi uwalnianie lotnych związków organicznych w trakcie mechanicznego mieszania poszczególnych składników mieszaniny wiążącej. Mając to na uwadze, w testach laboratoryjnych oceniono możliwość zastosowania tej technologii do unieszkodliwiania gleby piaszczystej zanieczyszczonej toluenem. Do stabilizacji/zestalania takiej gleby zastosowano trzy mieszaniny wiążące (zestalające) na bazie cementu portlandzkiego (CEM I 42,5 R), zawierające ponadto ziemię okrzemkową lub kord tekstylny z dużą ilości odpadowej gumy z opon. Te dodatkowe składniki pełniły rolę adsorbentów ograniczających emisję toluenu. W trakcie procesu prowadzono monitoring emitowanych zanieczyszczeń gazowych. Ocenę wpływu składu mieszaniny wiążącej (zestalającej) na emisję toluenu przeprowadzono na podstawie analizy stężeń chwilowych C7H8 zarejestrowanych detektorem płomieniowo-jonizacyjnym nad powierzchnią mieszaniny reakcyjnej. Wyniki badań potwierdziły korzystny wpływ hermetyzacji zanieczyszczonej gleby z użyciem cementu portlandzkiego. Zastosowanie cementu w ilości 50% masy gleby zmniejszyło całkowitą emisję toluenu o ponad 26%. Podobne efekty uzyskano stosując cement z dodatkiem ziemi okrzemkowej lub kordu tekstylnego.

8

Evaluation of the efficiency of the three-way catalytic converter of a spark ignition engine of the chosen aromatic hydrocarbons removing

Skrętowicz M., Woźniak J., Wróbel R.

Combustion Engines

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2017

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R. 56, nr 2

83--86

EN

In the paper the results of measurement of the most popular aromatic hydrocarbons (benzene, toluene and xylenes) in the exhaust of spark ignition engine before and after three-way catalytic reactor were presented. The investigations have been conducted at fixed rotational speed, 2500 rpm and at a few different values of torque in range 0 – 80 Nm, every 10 Nm. Based on obtained results, the calculations of catalytic reactor efficiency in removing analysed components have been made. The measurements showed high efficiency of the catalytic converter in reduction of that pollutants in exhaust gases.

9

Two-step treatment of harmful industrial wastewater: an analysis of microbial reactor with integrated membrane retention for benzene and toluene removal

Trusek-Holownia A., Noworyta A.

Polish Journal of Chemical Technology

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2015

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Vol. 17, nr 4

15--22

EN

Standards for highly toxic and carcinogenic pollutants impose strict guidelines, requiring values close to zero, regarding the degradation of such pollutants in industrial streams. In many cases, classic bioremoval processes fail. Therefore, we proposed a stream leaving the microbial membrane bioreactor (MBR) that is directed to an additional membrane separation mode (NF/RO). Under certain conditions, the integrated process not only benefits the environment but may also increase the profitability of the bioreactor operation. An appropriate model was developed and tested in which the bioremoval of benzene and toluene by Pseudomonas fluorescens was used as an example. This paper presents equations for selecting the operation parameters of the integrated system to achieve the expected degree of industrial wastewater purification.

10

Noble metal modified TiO2 for photocatalytic air purification

Klein M., Grabowska E., Zaleska A.

Physicochemical Problems of Mineral Processing

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2015

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Vol. 51, iss. 1

49--57

EN

TiO2 was surface modified with silver, gold, palladium and platinum ion clusters to improve its photocatalytic activity. The effect of metal content and kind of dopant used during preparation procedure on the photoactivity were investigated. in toluene removal which was used as a model volatile organic compound. Toluene, at the concentration of about 100 ppm, was irradiated over noble metal modified TiO2 using light-emitting diodes (LEDs) in four subsequent cycles.

11

Destrukcyjne utlenianie domieszki toluenu w powietrzu w reaktorze koronowym i reaktorze hybrydowym, koronowo-katalitycznym

Parus W., Paterkowski W., Straszko J.

Inżynieria i Aparatura Chemiczna

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2013

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Nr 4

361--363

PL

Przedstawiono wyniki badań destrukcyjnego utleniania domieszki toluenu w powietrzu w reaktorze koronowym i reaktorze hybrydowym, koronowo - katalitycznym. Stosowano zasilacz i reaktory własnej konstrukcji oraz katalizator (4 g) o składzie 45% mas. Mn02 + 30% mas. Fe203 +25 % mas. CuO, otrzymany w laboratorium autorów. Pomiary wykonano przy różnych parametrach pracy zasilacza. Napięcie zasilania zmieniano w zakresie 13,2÷13,6 kV a częstotliwość prądu w przedziale 0 ÷ 1,8 kHz. Stężenia toluenu zmieniano w zakresie 0,78+7,20 g/m3, a przepływ gazu w granicach 520÷1475 dm3/h. Ustalono, że zależnie od parametrów zasilania, objętościowego przepływu gazów i temperatury gazów uzyskuje się w reaktorze koronowym stopnie destrukcji toluenu do produktów nietoksycznych (C02 i H2O) w zakresie 0,178÷0,755, a w reaktorze hybrydowym koronowo-katalitycznym w granicach 0,29÷0,958. Stwierdzono, że wzrost częstotliwości pracy generatora powoduje zwiększenie stopnia przemiany w obu typach reaktorów. Natomiast zwiększenie objętościowego przepływu gazów skutkuje obniżeniem stopnia przemiany tej domieszki.

EN

Research results dealing with the destructive oxidation of toluene admixture in air using a corona and hybrid corona - catalytic reactors are presented. A generator and reactors of authors’ own design and catalyst (4 g) of composition 45 wt. % Mn02, 30 wt. % Fe203 and 25 wt. % CuO obtained in authors own laboratory were used. The measurements were performed for different parameters of generator operation. A generator voltage varied in a range from 13.2 to 13.6 kV, whereas current frequency in a range of 0.4÷1.8 kHz. The toluene concentration was changed in a range 0.78÷7.20 g/m3 and gas flow rate within a range 520÷1475 Ndm3/ h. It was established that depending on generator parameters, volume gas flow rate and gas temperature, the destruction degree of toluene to non-toxic products (C02 i H2O) achieved for the corona and hybrid corona - catalytic reactors were in a range of 0.178÷0.755 and 0.29÷0.958, respectively. It was found that the increase of generator operational frequency caused the enhancement of toluene conversion degree for both types of reactors. On the other hand, the increase of volume gas flow rate resulted in the decrease of toluene conversion degree.

12

Catalytic decomposition of toluene over La1-xSr xMnO3/palygorskite synthesized catalysts

Song L., Chen T., Chen D., Chen Y., Xie J., Liu H.

Environment Protection Engineering

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2013

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Vol. 39, nr 3

31--42

EN

Palygorskite (PG) supported La1-xSrxMnO3 catalysts were fabricated by copreripitation. The catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), specific surface area (SSA) and H2 temperature programmed reduction (H 2-TPR). Catalytic activity for VOCs was examined by using toluene as a model compound. The results show that the surface area as well as mechanical strength of catalysts increase substantially after catalysts loaded in PG. XRD patterns show that after calcination at 700 0C, PG as a support in 9% LaMn03/PG and 9% La0.7Sr0.3MnO3/PG was transformed into amorphous phase and the morphology was not destroyed. It was well established that the main reductive components are factually Mn(III) or Mn(IV) oxides in catalysts based on the results of TPR. It was also found that Mn(IV) increases while Mn(III) reduces responding with the increasing amount of Sr. Toluene conversion rate of as-preparedμ% La1-xSr xMnO3/PG increases with the increasing values of x and μ when x=0-0.3 and μ = 3-9%. Toluene can be converted completely at 285 0C by 9% La0.7Sr0.3MnO3/PG catalyst while no significant change was observed after addition on the doping and loading amount of Sr. During a 100 h stability experiment of 9% La 0.7Sr0.3MnO3/PG catalyst, toluene removal was found to be above 95%.

13

Zastosowanie statycznej techniki headspace GC-MS do oznaczania benzenu, toluenu, etylobenzenu i ksylenu w glebie i roślinach

Górska S., Delis M., Chaber P.

Przemysł Chemiczny

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2012

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T. 91, nr 4

569-573

PL

Do oznaczania benzenu, toluenu, etylobenzenu i ksylenu w próbkach gleb i roślin zastosowano technikę headspace. Próbki analizowano metodą chromatografii gazowej sprzężonej ze spektrometrią mas (GC-MS). Opracowana procedura pozwala w sposób szybki i prosty uzyskać informację o zawartości BTEX w próbkach środowiskowych z pominięciem długiego etapu przygotowania próbki. Opracowaną metodę charakteryzuje wysoka czułość oraz zadowalające wartości odzysku (40–132%) i współczynnika zmienności (CV<30%). Granica wykrywalności metody wynosi 0,06 ng/mL.

EN

PhH, PhMe, PhEt and xylene isomers were detd. in plant, soil and ref.soil samples by static headspace anal. performed by using gas chromatog. coupled with mass spectrometry. Good sensitivity as well as satisfactory recovery and precision were achieved. The limits of the hydrocarbon detection reached at 0.06 ng/mL levels.

14

Mechaniczne właściwości mieszanin nitrocelulozy z wybranymi związkami małocząsteczkowymi

Wolszakiewicz T.

Przemysł Chemiczny

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2012

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T. 91, nr 10

2022-2026

PL

Stopione nitropochodne toluenu i difenyloaminy mieszano z drzewną nitrocelulozą. W mieszaninach oznaczano entalpie topnienia, średnie masy cząsteczkowe i moduły Younga. Dane liczbowe zestawiono w tabelach i skorelowano odpowiednimi równaniami wielomianowymi.

EN

Com. nitrocellulose was mixed with 5 molten nitrotoluenes and nitrodiphenylamines. The mixts. were studied for melting enthalpy, av. mol. mass and Young modulus. The numerical data were tabulated and correlated as resp. polynomial equations.

15

Benzene and Toluene Removal by Carbon Nanotubes from Aqueous Solution

Bina B., Amin M. M., Rashidi A., Pourzamani H.

Archives of Environmental Protection

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2012

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Vol. 38, no. 1

3-25

EN

The removal of benzene (B) and toluene (T) from aqueous solution by multi walled, single walled, and hybrid carbon nanotubes (MWCNTs, SWCNTs, and HCNTs) was evaluated for a nanomaterial dose of 1 g/l, concentration of 10-100 mg/l, and pH 7. The equilibrium amount removed by SWCNTs (B: 9.98 mg/g and T: 9.96 mg/g) was higher than for MWCNTs and HCNTs. Toluene has a higher adsorption tendency on CNTs than benzene, which is related to the increasing water solubility and the decreasing molecular weight of the compounds. The SWCNTs performed better for B and T sorption than the MWCNTs and HCNTs. Isotherms study based on isofit program indicate that the Generalized Langmuir-Freundlich (GLF) isotherm expression provides the best fit for benzene sorption, and that Brunauer-Emmett-Teller (BET) isotherm is the best fit for toluene adsorption by SWCNT. SWCNTs are efficient B and T adsorbents and possess good potential applications to water and wastewater treatment and maintain water of high quality that could be used for cleaning up environmental pollution.

16

Benzen, cykloheksan, etylobenzen, n-heksan, metylocykloheksan, toluen – metoda oznaczania

Domański W.

Podstawy i Metody Oceny Środowiska Pracy

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2011

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Nr 1 (67)

35--44

XX

Metoda polega na adsorpcji na węglu aktywnym zawartych w powietrzu par: benzenu, cykloheksanu, etylobenzenu, n-heksanu, metylocykloheksanu i toluenu, a następnie desorpcji disiarczkiem węgla oraz analizie chromatograficznej roztworu uzyskanego w wyniku desorpcji.Metodę stosuje się do oznaczania wymienionych węglowodorów w powietrzu na stanowiskach pracy podczas przeprowadzania kontroli warunków sanitarnych. Oznaczalność metody wynosi: 0,15 mg benzenu, 7,5 mg cykloheksanu, 5 mg etylobenzenu, 3,75 mg n-heksanu, 25 mg metylocykloheksanu i 5 mg toluen w 1 m3 powietrza.

EN

This method is based on the adsorption of benzene cyclohexane, ethylbenzene, n-hexane, methy-locyclohexane and toluene vapors on active charcoal, desorption with carbon disulphide and determination with gas chromatography with an FID detector. The determination limit of this method in the air sample is 0.15 mg/m3 for benzene, 7.5 mg/m3 for cyclohexane, 5 mg/m3 for ethylbenzene, 3.75 mg/m3 for n-hexane, 25 mg/m3 for methylcyclohexane and 5 mg/m3 for toluene.

17

Aktywność katalizatorów perowskitowych z dodatkiem platyny w utlenianiu organicznych zanieczyszczeń powietrza

Musialik-Piotrowska A.

Ochrona Środowiska

|

2011

|

Vol. 33, nr 1

19-24

PL

Katalizatory tlenkowe oparte na tlenkach złożonych o strukturze perowskitu zazwyczaj wykazują wysoką aktywność w utlenianiu związków tlenopochodnych, natomiast zwykle są mało aktywne w utlenianiu węglowodorów, szczególnie aromatycznych. Do badań wykonano katalizatory na bazie perowskitu (LaMnO3), z dodatkiem platyny wprowadzonej do fazy aktywnej, na monolitycznym nośniku metalowym z warstwą pośrednią gamma-Al2O3. Przebadano je w utlenianiu toluenu oraz acetonu i octanu etylu, spalanych indywidualnie i w mieszaninach dwuskładnikowych - węglowodór i pochodna tlenowa. Wykazano, że utlenianie samego toluenu zachodziło do produktów końcowych - CO2 i H2O, natomiast związki tlenowe utleniały się poprzez produkty pośrednie - aldehyd octowy - w spalaniu obu związków oraz etanol - podczas spalania octanu etylu. W przypadku wszystkich katalizatorów niewielki wzajemny wpływ na spalanie każdego ze związków zaobserwowano spalając mieszaninę toluen-aceton, wyraźnie większy w przypadku mieszaniny toluen-octan etylu. Spalanie toluenu w mieszaninach na mniej aktywnych katalizatorach przebiegało poprzez benzen. W obecności obu katalizatorów dotowanych platyną, podczas spalania mieszanin stężenie aldehydu octowego zmalało, prawdopodobnie wskutek lokalnego wzrostu temperatury na platynie w wyniku spalenia toluenu. Najwyższą aktywność wykazał katalizator z dodatkiem platyny wstępnie naniesionej na gamma-Al2O3, o ogólnej zawartości czynnika aktywnego 20% mas. Stwierdzono, że minimalna zawartość czynnika aktywnego w przypadku katalizatorów tlenkowych nie powinna być mniejsza niż 15% mas.

EN

Metal oxide perovskite-type catalysts usually show high activity for oxidizing oxy-derivative compounds, but they are much less active in the oxidation of hydrocarbons, particularly aromatics. For the purpose of the study, LaMnO3-based catalysts, with platinum incorporated into the active phase, were prepared on monolithic metallic supports washcoated with gamma-Al2O3. The catalysts were tested in the oxidation of toluene, as well as acetone and ethyl acetate, which were combusted separately or in two-component mixtures - hydrocarbon and oxy-derivative. It has been demonstrated that when toluene alone was oxidized, the reaction ran to final products - CO2 and H2O, while oxygen compounds were oxidized via intermediate products - acetaldehyde during combustion of both compounds, and ethanol during combustion of ethyl acetate. With all the catalysts tested, the "mixture effect" of each component was insignificant during oxidation of the toluene-acetone mixture, and noticeably stronger during combustion of the toluene-ethyl acetate mixture. The combustion of toluene in mixtures over catalysts of lower activity occurred via benzene. In the presence of Pt-doped catalysts, the concentration of acetaldehyde during combustion of mixtures decreased, which was probably due to a local rise in temperature on the Pt active sites as a result of toluene oxidation. The highest activity was that of the catalyst where platinum was deposited onto gamma-Al2O3, and the total content of the active phase amounted to 20 wt. %. It has been found that in the case of metal oxide catalysts the minimal content of the active phase can not be lower than 15 wt. %.

18

Model of aromatic hydrocarbons transport in porous ground media

Gawdzik J.

Proceedings of ECOpole

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2010

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Vol. 4, No. 1

29--35

EN

Dispersion model of NAPL hydrocarbons’ transport in porous media has been presented. Mathematical model allows to estimate whether the menace of ground water can occur as a result of hydrocarbons’ transport through the soil. The convection in mass transport is considered in the general equation due to the higher velocity of propagation in vertical direction. The introduction of the equation of biosorption link allows to take into account microorganisms’ influence on impurities concentration, especially on heavy oils derived compounds. The research conducted on a filter model was the first step to verify the dispersion model of petroleum derived substances. Dispersion coefficient was assessed for benzene, toluene and ethylbenzene.

PL

W pracy wprowadzono dyspersyjno-konwekcyjny model migracji węglowodorów ropopochodnych w gruntach. Proponowany model jest próbą znalezienia mechanizmu propagacji węglowodorów przez ośrodek porowaty i pozwala przewidzieć, na ile migracja benzenu, toluenu i etylobenzenu jest w stanie zagrozić zwierciadłu wód podziemnych. Uwzględnienie konwekcji w równaniu transportu masy podyktowane jest zwiększoną szybkością migracji węglowodorów w kierunku pionowym. Wprowadzenie równania biosorpcji pozwala uwzględnić wpływ mikroorganizmów na zmianę stężenia, głównie ciężkich węglowodorów ropopochodnych w gruncie. Poprawność modelu zweryfikowano doświadczalnie na modelu filtra gruntowego poprzez wyznaczenie współczynnika dyspersji wzdłużnej dla benzenu, toluenu i etylobenzenu.

19

Dielectric Loss Tangent Of Fullerene-Doped Hydrocarbons

Aksamit P.

Zeszyty Naukowe. Elektryka / Politechnika Opolska

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2009

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z. 62

9-10

EN

The paper presents the concept of modifying dielectric properties of insulation liquids using C60 fullerene. Three hydrocarbons were doped with different amounts of C60 fullerene and the influence of this modification on dielectric loss tangent was determined.

20

Decomposition of toluene in air mixtures under electron beam irradiation

Sun Y., Chmielewski A. G., Bułka S., Zimek Z.

Nukleonika

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2009

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Vol. 54, No. 2

65-70

EN

The model gases of toluene-air mixtures were prepared by blowing technical air into liquid toluene and then irradiated with an ILU-6 accelerator located at the Institute of Nuclear Chemistry and Technology (INCT), Poland. It was found that the decomposition efficiency of toluene increases with absorbed dose and decreases with initial concentration of toluene. At 14.5 kGy dose, the decomposition efficiencies of toluene were 50, 37 and 34.5% for the initial concentrations of toluene 32.0, 63.4 and 78.0 ppm, respectively. At 58.0 kGy dose, the decomposition efficiencies of toluene were 93.8 and 78.1%, the initial concentrations of toluene being 32.0 and 63.4 ppm, respectively. Benzaldehyde was identified as one of the by-products of toluene decomposition in an air mixture. The decomposition efficiency and by-product formation under EB irradiation were compared between toluene and 4-chlorotoluene.