Tuning the composition of plasma-activated water by a surface-wave microwave discharge and a kHz plasma jet

The physicochemical properties of water activated by high-purity low-temperature argon plasma of electrodeless microwave discharge at atmospheric pressure are investigated. Such parameters of activated water as electrical conductivity, redox potential, hydrogen index (pH), the concentrations of dissolved molecular oxygen, hydrogen peroxide, OH-radicals, nitrate and nitrite anions depending on the plasma jet distance above the water surface and duration of activation were studied. Under irradiation conditions close to optimum, it was shown that the generation rate in the absence of impurities are 200 μM/min for H2O2; 800 μM/min for •OH and 2 mM/min for NOx−. The use of plasma activated water (PAW) in agriculture has been tested. It was shown that strawberry seeds treated with a surfactant solution grow much faster than control seeds. The mechanisms of the chemical composition formation of activated water and its biological properties are discussed.

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Plasma-catalytic conversion of CO 2 and CO 2 /H 2 O in a surface-wave sustained microwave discharge

Applied Catalysis B Environmental ◽

10.1016/j.apcatb.2017.05.032 ◽

2017 ◽

Vol 214 ◽

pp. 114-125 ◽

Cited By ~ 26

Author(s):

Guoxing Chen ◽

Thomas Godfroid ◽

Nikolay Britun ◽

Violeta Georgieva ◽

Marie-Paule Delplancke-Ogletree ◽

...

Keyword(s):

Surface Wave ◽

Microwave Discharge ◽

Catalytic Conversion

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Modelling of a microwave discharge created by a standing surface wave

Journal of Physics D Applied Physics ◽

10.1088/0022-3727/25/6/009 ◽

1992 ◽

Vol 25 (6) ◽

pp. 953-959 ◽

Cited By ~ 14

Author(s):

Z Rakem ◽

P Leprince ◽

J Marec

Keyword(s):

Surface Wave ◽

Microwave Discharge

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Tailoring the Chemistry of Plasma-Activated Water Using a DC-Pulse-Driven Non-Thermal Atmospheric-Pressure Helium Plasma Jet

Plasma ◽

10.3390/plasma2020010 ◽

2019 ◽

Vol 2 (2) ◽

pp. 127-137 ◽

Cited By ~ 1

Author(s):

Oh ◽

Szili ◽

Hatta ◽

Ito ◽

Shirafuji

Keyword(s):

Hydrogen Peroxide ◽

Atmospheric Pressure ◽

Pulse Width ◽

Plasma Jet ◽

Plasma Jets ◽

Helium Plasma ◽

Uv Absorption Spectroscopy ◽

Pulse Polarity ◽

Plasma Activated Water

We investigate the use of a DC-pulse-driven non-thermal atmospheric-pressure He plasma jet in the regulation of hydrogen peroxide (H2O2), nitrite (NO2−), nitrate (NO3−), and oxygen (O2) in deionized (DI) water. The production of these molecules is measured by in situ UV absorption spectroscopy of the plasma-activated water (PAW). Variations in the pulse polarity and pulse width have a significant influence on the resultant PAW chemistry. However, the trends in the concentrations of H2O2, NO2−, NO3−, and O2 are variable, pointing to the possibility that changes in the pulse polarity and pulse width might influence other plasma variables that also impact on the PAW chemistry. Overall, the results presented in this study highlight the possibility of using DC-pulse-driven plasma jets to tailor the chemistry of PAW, which opens new opportunities for the future development of optimal PAW formulations across diverse applications ranging from agriculture to medicine.

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Propagation of Microwave Discharge Sustained by Surface Wave in Quartz Tube Filled with Low-Pressure Air

Plasma Physics Reports ◽

10.1134/s1063780x20080127 ◽

2020 ◽

Vol 46 (8) ◽

pp. 837-845

Author(s):

V. I. Zhukov ◽

D. M. Karfidov ◽

K. F. Sergeichev

Keyword(s):

Surface Wave ◽

Microwave Discharge ◽

Low Pressure ◽

Quartz Tube

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Influence of Nonthermal Atmospheric Plasma-Activated Water on the Structural, Optical, and Biological Properties of Aspergillus brasiliensis Spores

Applied Sciences ◽

10.3390/app10186378 ◽

2020 ◽

Vol 10 (18) ◽

pp. 6378

Author(s):

Se Hoon Ki ◽

Hyeongjin Noh ◽

Geum Ran Ahn ◽

Seong Hwan Kim ◽

Nagendra K. Kaushik ◽

...

Keyword(s):

Cell Wall ◽

Fungal Spores ◽

Plasma Jet ◽

Biological Properties ◽

Atmospheric Plasma ◽

Air Plasma ◽

Activation Time ◽

Aspergillus Brasiliensis ◽

Plasma Activation ◽

Plasma Activated Water

Plasma-activated water (PAW) has emerged as a platform for sterilizing fungal pathogens. In this study, we investigated the influence of PAW on black melanized spores of Aspergillus brasiliensis to explore the mechanism of fungal spore inactivation. PAW was prepared by activating deionized water with a nonthermal atmospheric pressure air plasma jet (soft plasma jet). The concentrations of H2O2 and NOx in the PAW treated by the soft plasma jet for 3 min were 50 μM and 1.8 mM, respectively, and the pH of the PAW was 3.10. The reactive oxygen and nitrogen species (RONS) in the PAW increased with longer plasma activation time. After being treated for 30 min in the PAW with a plasma activation time of 3 min, the spore viability dramatically dropped to 15%. The viabilities of 0.3% H2O2- and 0.3% HNO3-treated spores were 22% and 42%, respectively. The breakage of the spore cell wall by the PAW was revealed in scanning electron microscope images and flow cytometry measurements. Disruption of cell wall integrity provides a path for intracellular components to escape and RONS of the PAW can attack intracellular components directly. Degradation of high molecular genomic DNA was also observed by agarose gel electrophoresis. These results suggest that long-lived reactive species generated in the PAW play an important role in the inactivation of melanized fungal spores. Consequently, PAW produced by a soft plasma jet can be applied to sterilize bioprotective walled fungal spores in a relatively large volume.

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The Antibacterial Efficacy and Mechanism of Plasma-Activated Water Against Salmonella Enteritidis (ATCC 13076) on Shell Eggs

Foods ◽

10.3390/foods9101491 ◽

2020 ◽

Vol 9 (10) ◽

pp. 1491

Author(s):

Chia-Min Lin ◽

Chun-Ping Hsiao ◽

Hong-Siou Lin ◽

Jian Sin Liou ◽

Chang-Wei Hsieh ◽

...

Keyword(s):

Flow Rate ◽

Salmonella Enteritidis ◽

Air Flow ◽

Plasma Jet ◽

Cell Permeability ◽

Antibacterial Efficacy ◽

Bacterial Cells ◽

Air Flow Rate ◽

Shell Eggs ◽

Plasma Activated Water

Eggs are one of the most commonly consumed food items. Currently, chlorine washing is the most common method used to sanitize shell eggs. However, chlorine could react with organic matters to form a potential carcinogen, trihalomethanes, which can have a negative impact on human health. Plasma-activated water (PAW) has been demonstrated to inactivate microorganisms effectively without compromising the sensory qualities of shell eggs. For this study, various amounts (250, 500, 750, or 1000 mL) of PAW were generated by using one or two plasma jet(s) at 60 watts for 20 min with an air flow rate at 6 or 10 standard liters per minute (slm). After being inoculated with 7.0 log CFU Salmonella Enteritidis, one shell egg was placed into PAW for 30, 60, or 90 s with 1 or 2 acting plasma jet(s). When 2 plasma jets were used in a large amount of water (1000 mL), populations of S. Enteritidis were reduced from 7.92 log CFU/egg to 2.84 CFU/egg after 60 s of treatment. In addition, concentrations of ozone, hydrogen peroxide, nitrate, and nitrite in the PAW were correlated with the levels of antibacterial efficacy. The highest concentrations of ozone (1.22 ppm) and nitrate (55.5 ppm) were obtained with a larger water amount and lower air flow rate. High oxidation reduction potential (ORP) and low pH values were obtained with longer activation time, more plasma jet, and a lower air flow rate. Electron paramagnetic resonance (EPR) analyses demonstrated that reactive oxygen species (ROS) were generated in the PAW. The observation under the scanning electron microscope (SEM) revealed that bacterial cells were swollen, or even erupted after treatment with PAW. These results indicate that the bacterial cells lost control of cell permeability after the PAW treatment. This study shows that PAW is effective against S. Enteritidis on shell eggs in a large amount of water. Ozone, nitrate, and ROS could be the main causes for the inactivation of bacterial cells.

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Emission spectrum analysis of an atmospheric electrode microwave discharge in argon flow and of a cold plasma jet on its base

Journal of Physics Conference Series ◽

10.1088/1742-6596/1698/1/012029 ◽

2020 ◽

Vol 1698 ◽

pp. 012029

Author(s):

S.N. Antipov ◽

M.A. Sargsyan ◽

M.Kh. Gadzhiev

Keyword(s):

Emission Spectrum ◽

Spectrum Analysis ◽

Cold Plasma ◽

Microwave Discharge ◽

Plasma Jet ◽

Argon Flow

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Chromatographic analysis of a cold plasma jet generated by an electrode microwave discharge in argon flow, interacting with atmospheric air

Journal of Physics Conference Series ◽

10.1088/1742-6596/2100/1/012029 ◽

2021 ◽

Vol 2100 (1) ◽

pp. 012029

Author(s):

V M Chepelev ◽

A V Chistolinov ◽

S N Antipov ◽

M Kh Gadzhiev

Keyword(s):

Cold Plasma ◽

Microwave Discharge ◽

Microwave Plasma ◽

Plasma Jet ◽

Plasma Source ◽

Nonequilibrium Plasma ◽

Vibrationally Excited ◽

Gaseous Products ◽

Argon Flow ◽

Co Concentration

Abstract Application of gas chromatography in analysis of a cold plasma jet generated by an atmospheric pressure microwave discharge in argon flow was considered. Previously developed 2.45-GHz-plasmatron with the external 6-rod-electrode plasma torch was used as a microwave plasma source. The analysis of gaseous samples showed that CO concentration increases by 5-6 times and new gaseous products appear – H2 and CH4 as a result of plasma-gas interaction. The production of CO, H2 and O2 occurs in the processes of dissociation of CO2 and water vapor in the nonequilibrium plasma through the vibrationally excited states.

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Surface wave propagation in an ideal Hall-magnetohydrodynamic plasma jet in flowing environment

Physics of Plasmas ◽

10.1063/1.1795195 ◽

2004 ◽

Vol 11 (11) ◽

pp. 4904-4910 ◽

Cited By ~ 1

Author(s):

Himanshu Sikka ◽

Nagendra Kumar ◽

Ivan Zhelyazkov

Keyword(s):

Wave Propagation ◽

Surface Wave ◽

Plasma Jet ◽

Surface Wave Propagation

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