Plasma

33 pages, 4212 KiB

Open AccessArticle

Spectroscopic Measurements of Dissolved O₃, H₂O₂ and OH Radicals in Double Cylindrical Dielectric Barrier Discharge Technology: Treatment of Methylene Blue Dye Simulated Wastewater

by Emile Salomon Massima Mouele, Jimoh. O. Tijani, Milua Masikini, Ojo. O. Fatoba, Chuks P. Eze, Chionydua T. Onwordi, Myo Tay Zar Myint, Htet Htet Kyaw, Jamal Al-Sabahi, Mohammed Al-Abri, Sergey Dobretsov, Katri Laatikainen and Leslie. F. Petrik

Plasma 2020, 3(2), 59-91; https://doi.org/10.3390/plasma3020007 - 18 May 2020

Cited by 23 | Viewed by 6063

Abstract

Advanced oxidation technologies (AOTs) focusing on nonthermal plasma induced by dielectric barrier discharge are adequate sources of diverse reactive oxygen species (ROS) beneficial for water and wastewater treatment. In this study, indigo, peroxytitanyl sulphate and terephthalic acid methods were used to approximate the concentrations of O₃, H₂O₂ and OH produced in a double cylindrical dielectric barrier discharge (DCDBD) plasma configuration. The effect of pH and scavengers as well as the amount of chemical probes on the generation of oxidants was investigated. The efficiency of the DCDBD reactor was further evaluated using methylene blue (MB) as model pollutant. The results demonstrated that the formation of oxidants O₃, H₂O₂ and OH in the DCDBD reactor was pH-dependent. Furthermore, the presence of scavengers such as phosphates, bicarbonates and carbonates in the solution diminished the amount of OH in the system and hence could impact upon the degree of detoxification of targeted pollutants during water and wastewater treatment. The MB simulated dye was totally decomposed into H₂O, dissolved CO₂ and simpler aqueous entities. Herein the DCDBD design is an adequate AOT that can be used worldwide for effective decontamination of water and wastewater. Full article

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5 pages, 227 KiB

Open AccessEditorial

Low Temperature Plasma Jets: Characterization and Biomedical Applications

by Mounir Laroussi

Plasma 2020, 3(2), 54-58; https://doi.org/10.3390/plasma3020006 - 3 Apr 2020

Cited by 10 | Viewed by 4241

Abstract

For many decades non-equilibrium plasmas (NEPs) that can be generated at atmospheric pressure have played important roles in various material and surface processing applications [...] Full article

16 pages, 1325 KiB

Open AccessEditor’s ChoiceArticle

Spatially-Resolved Spectroscopic Diagnostics of a Miniature RF Atmospheric Pressure Plasma Jet in Argon Open to Ambient Air

by Florent P. Sainct, Antoine Durocher-Jean, Reetesh Kumar Gangwar, Norma Yadira Mendoza Gonzalez, Sylvain Coulombe and Luc Stafford

Plasma 2020, 3(2), 38-53; https://doi.org/10.3390/plasma3020005 - 1 Apr 2020

Cited by 10 | Viewed by 4247

Abstract

The spatially-resolved electron temperature, rotational temperature, and number density of the two metastable Ar

1 s

levels were investigated in a miniature RF Ar glow discharge jet at atmospheric pressure. The

1 s

level population densities were determined from optical absorption spectroscopy (OAS) [...] Read more.

The spatially-resolved electron temperature, rotational temperature, and number density of the two metastable Ar

1 s

levels were investigated in a miniature RF Ar glow discharge jet at atmospheric pressure. The

1 s

level population densities were determined from optical absorption spectroscopy (OAS) measurements assuming a Voigt profile for the plasma emission and a Gaussian profile for the lamp emission. As for the electron temperature, it was deduced from the comparison of the measured Ar

2 p_{i} \to 1 s_{j}

emission lines with those simulated using a collisional-radiative model. The Ar

1 s

level population higher than 10

^{18}

^{- 3}

and electron temperature around 2.5 eV were obtained close to the nozzle exit. In addition, both values decreased steadily along the discharge axis. Rotational temperatures determined from OH(A) and N

_{2}

(C) optical emission featured a large difference with the gas temperature found from a thermocouple; a feature ascribed to the population of emitting OH and N

_{2}

states by energy transfer reactions involving the Ar

1 s

levels. Full article

(This article belongs to the Special Issue Low Temperature Plasma Jets: Physics, Diagnostics and Applications)

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