Wyniki wyszukiwania - Biblioteka Nauki

1

‘Zero energy’ electron beam technology for sludge hygienization

100%

Chmielewski A. G. , Sudlitz M.

Nukleonika

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2019

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tom Vol. 64, No. 2

55--63

EN

Large quantity of sewage sludge originating from wastewater treatment plants is becoming a growing problem from environmental and human health points of view. One of the ways to use sewage sludge is agricultural purpose due to its nutrients and organic matter content, but the condition is that it should be deprived of pathogenic bacteria and parasite egg contamination. Application of ionizing radiation to hygienize sewage sludge can make it appropriate for agricultural use. The process does not require addition of chemicals to sludge; it is environmentally friendly and effective in removal of biological threats. In the past, successful attempts of sewage sludge treatment using ionizing radiation were made. Pilot plants and commercial ones proved that pathogens can be easily removed from sewage sludge by ionizing radiation. The concept of ‘zero energy’ biogas plant is based on the construction of a complex system consisting of biogas plant and electron accelerator in the biofertilizer manufacturing line. Digestate originating from the methane fermentation of sewage sludge is irradiated to remove all pathogens using electron beam from an accelerator powered by electric energy obtained from burning biogas in a cogenerator. The product is a high-quality, biologically safe fertilizer.

2

Electron beam technology for biogas and biofertilizer generation at municipal resource recovery facilities

80%

Chmielewski A. G. , Sudlitz M. , Han B. , Pillai S. D.

Nukleonika

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2021

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tom Vol. 66, No. 4

213--219

EN

In the era of circular economies, municipal wastewater treatment plants (WWTPs) are viewed as resource recovery facilities. At the very minimum, the targeted resources are water, biogas, and phosphorus. However, municipal wastewater streams (sludge and effluent) need to be adequately treated to eliminate the potential for the transmission of microbial pathogens including protozoa, bacteria, and viruses. This paper presents the results from a study demonstrating the use of electron beam technology for sludge hygenization and enhanced methane (biogas) production using municipal wastewater samples. Cogeneration of heat for fertilizer drying and granulation and electricity for powering the electron beam system are also demonstrated.

3

Computer-simulated degradation of CF3Cl, CF2Cl2, and CFCl3 under electron beam irradiation

80%

Kabasa S. , Sun Y. , Chmielewski A. G. , Nichipor H.

Nukleonika

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2023

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tom Vol. 68, No. 3

67--76

EN

Electron beam treatment technologies should be versatile in the removal of chlorofl uorocarbons (CFCs) owing to their exceptional cross sections for the thermal electrons generated in the radiolysis of air. Humidity, dose rates, O2 concentration, and CFC concentration infl uence the effi ciency of the destruction process under electron beam treatment. Computer simulations have been used to theoretically demonstrate the destruction of chlorotrifl uoromethane (CF3Cl), dichlorodifl uoromethane (CF2Cl2), and trichlorofl uoromethane (CFCl3) in the air (N2 + O2: 80% + 20%) in room temperature up to a dose of 13 kGy. Under these conditions, it is predicted that the removal effi ciency is in the order CF3Cl (0.1%) < CF2Cl2 (7%) < CFCl3 (34%), which shows the dependence of the process on the number of substituted Cl atoms. Dissociative electron attachment with the release of Cl– is the primary process initiating the destruction of CFCs from the air stream. Reactions with the first excited state of oxygen, namely, O(1 D), and charge-transfer reactions further promote the degradation process. The degradation products can be further degraded to CO2, Cl2, and F2 by prolonged radiation treatment. Other predicted products can also be removed through chemical processes.

4

Możliwości zmniejszenia stężeń SO₂ i NOₓ w gazach odlotowych emitowanych z okrętowych silników Diesla

80%

Pawelec A. , Zwolińska E. , Sun Y. , Chmielewski A. G.

Przemysł Chemiczny

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2019

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tom T. 98, nr 1

56--63

PL

Przedyskutowano zagadnienia związane z emisją tlenków siarki i azotu w transporcie morskim oraz omówiono metody ograniczenia ich emisji. Przedstawiono przegląd technologii obecnie stosowanych w transporcie morskim do usuwania tlenków siarki i azotu z gazów odlotowych z silników Diesla oraz nowych innowacyjnych metod ze szczególnym uwzględnieniem technologii plazmowych, w tym opartych na wykorzystaniu wiązki elektronów. Wobec zaostrzających się wymagań co do wielkości emisji zanieczyszczeń plazmowe technologie kontroli emisji mogą stać się konkurencyjne w stosunku do obecnie stosowanych. Należy podkreślić, że wszystkie te procesy opierają się na znajomości chemii i chemii plazmy oraz jej roli w ograniczeniu emisji w sektorze energetycznym. Wiedza w tym zakresie jest również podstawą do rozwiązania tego nierozwiązanego dotąd problemu z dziedziny ochrony środowiska.

EN

A review, with 48 refs., of exhaust gas cleaning technols. currently used in the marine transport as well as tested new technols. including plasma ones.

5

Organic pollutant removal from marine diesel engine off-gases under electron beam and hybrid electron beam and wet scrubbing process

70%

Sun Y. , Chmielewski A. G. , Pawelec A. , Mattausch G. , Torims T.

Nukleonika

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2021

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tom Vol. 66, No. 4

193--199

EN

The removal of organic pollutants from ship emission was studied using two processes namely electron beam (EB) and hybrid EB with wet scrubbing process. A mobile accelerator unit was used to treat 4915 Nm3 /h of flue gas emitted from a tugboat in Riga Shipyard. A volume of 3 m3 seawater containing 36.8 mM of NaClO2 oxidant was used as a wet scrubber solution. Organic pollutants, mainly volatile organic pollutants (VOCs), were collected at three different sampling points, before and after irradiation vessels, and after wet-scrubber unit, respectively. They were collected with glass sampling bottles, tedlar bags, Coconut Shell Charcoal (CSC) sorbents and XAD-2 sorbents. CH3OH and CH3OH/CH2Cl2 (1:1) were used to extract VOCs from CSC and XAD-2 sorbents, respectively. Syringe filters were used to obtain the solid-free extraction solutions. They were concentrated using a micro-extractor under continuously blowing high-purity Ar. A gas chromatography–mass spectrometry (GC-MS) was used for analysis. The identified organic compounds were: aliphatic hydrocarbons (dodecane C12H26 to eicosane C20H42), aromatic hydrocarbon (toluene), esters (C3H7COOCH3, (C4H9OCO)2C6H4), nitro compounds (C3H5NO3, C4H7NO2) and acid (C7H15COOH). After 4.2 kGy EB irradiation, around 50–100% aliphatic hydrocarbons, 83% toluene and 7.5% (C4H9OCO)2C6H4 were removed from the off-gases, and after EB hybrid wet-scrubber process, most organic compounds including nitro compounds were removed. Only trace amount of toluene, hexadecane, octadecane and dibutyl phthalate were found to be present in the gas phase.

6

Plasma technology to remove NOx from off-gases

61%

Pawelec A. , Chmielewski A. G. , Sun Y. , Bułka S. , Torims T. , Pikurs G. , Mattausch G.

Nukleonika

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2021

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tom Vol. 66, No. 4

227--231

EN

Operation of marine diesel engines causes signifi cant emission of sulphur and nitrogen oxides. It was noticed worldwide and the regulations concerning harmful emissions were introduced. There were several solutions elaborated; however, emission control for both SOx and NOx requires two distinctive processes realized in separated devices, which is problematic due to limited space on ship board and high overall costs. Therefore, the electron beam flue gas treatment (EBFGT) process was adopted to ensure the abatement of the problem of marine diesel off-gases. This novel solution combines two main processes: fi rst the fl ue gas is irradiated with electron beam where NO and SO2 are oxidized; the second stage is wet scrubbing to remove both pollutants with high efficiency. Laboratory tests showed that this process could be effectively applied to remove SO2 and NOx from diesel engine off-gases. Different compositions of absorbing solution with three different oxidants (NaClO, NaClO2 and NaClO3) were tested. The highest NOx removal efficiency (>96%) was obtained when seawater-NaClO2-NaOH was used as scrubber solution at 10.9 kGy dose. The process was further tested in real maritime conditions at Riga shipyard, Latvia. More than 45% NOx was removed at a 5.5 kGy dose, corresponding to 4800 Nm3 /h off-gases arising from ship emission. The operation of the plant was the first case of examination of the hybrid electron beam technology in real conditions. Taking into account the experiment conditions, good agreement was obtained with laboratory tests. The results obtained in Riga shipyard provided valuable information for the application of this technology for control of large cargo ship emission.

7

Studies on uranium recovery from a U-bearing Radoniów Dump

61%

Kiegiel K. , Roubinek O. , Gajda D. , Kalbarczyk P. , Zakrzewska-Kołtuniewicz G. , Chmielewski A. G.

Nukleonika

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2021

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tom Vol. 66, No. 4

115--119

EN

This work reports the possibility of uranium recovery from a post-mining uranium ore dump in Poland by a bioleaching method. The studies were conducted on the dump leaching model with the mass of 570 kg of uranium bearing mineral material from Radoniów pile and in the periodic bioreactor with a work volume of 80 dm3 and with mechanical mixing and aeration of the charge. The uranium concentration in the examined material was about 800 ppm. In this process, the consortium of microorganisms isolated from former mines was used. It was composed of the following microorganisms: Bacillius, Pseudomonas, Sphingomonas, Thiobacillus, Halothiobacillus, Thiomonas, and Geothrix. The effi ciency of the uranium bioleaching process was 98% in the reactor, and a yield of 70% was obtained in the dump leaching model. The post-leaching solution contained signifi cant amounts of uranium ions that were separated in two stages: (1) by ion chromatography and then (2) by a two-step precipitation method. The resulting solution was a source of ammonium diuranate, the precursor of yellowcake (uranium oxides).