Characterization of the chemical activity of a pulsed corona discharge above water

F Bilea; C Bradu; N B Mandache; M Magureanu

doi:10.1016/j.chemosphere.2019.07.033

Characterization of the chemical activity of a pulsed corona discharge above water

Chemosphere. 2019 Dec:236:124302. doi: 10.1016/j.chemosphere.2019.07.033. Epub 2019 Jul 9.

Authors

F Bilea¹, C Bradu², N B Mandache¹, M Magureanu³

Affiliations

¹ Department of Plasma Physics and Nuclear Fusion, National Institute for Lasers, Plasma and Radiation Physics, Atomistilor Str. 409, P.O. Box MG-36, Magurele, Bucharest, 077125, Romania.
² Department of Plasma Physics and Nuclear Fusion, National Institute for Lasers, Plasma and Radiation Physics, Atomistilor Str. 409, P.O. Box MG-36, Magurele, Bucharest, 077125, Romania; Faculty of Biology, Department of Systems Ecology and Sustainability, University of Bucharest, Splaiul Independentei 91-95, Bucharest, 050095, Romania.
³ Department of Plasma Physics and Nuclear Fusion, National Institute for Lasers, Plasma and Radiation Physics, Atomistilor Str. 409, P.O. Box MG-36, Magurele, Bucharest, 077125, Romania. Electronic address: monica.magureanu@inflpr.ro.

PMID: 31306974
DOI: 10.1016/j.chemosphere.2019.07.033

Abstract

A pulsed corona discharge above liquid combined with ozonation has been investigated for the degradation of organic pollutants in water, as well as regarding the generation of several oxidizing species: ozone in gas phase, hydrogen peroxide and hydroxyl radicals in the liquid. A considerable improvement in the energy efficiency for organic compounds removal has been observed when reducing the width of the discharge pulses. This finding was correlated with the efficient formation of oxidizing species in case of short pulses. Recycling of the effluent gas from the plasma also enhances contaminants degradation. This was mainly attributed to an in situ peroxone process, i.e. the reaction between plasma-generated O₃ and H₂O₂, forming highly reactive OH radicals, largely responsible for organic compounds degradation. This assumption is supported by the decline in O₃ and H₂O₂ concentrations and simultaneous increase in OH concentration detected in plasma-ozonation experiments as compared to results obtained with plasma alone.

Keywords: Hydrogen peroxide; Hydroxyl radicals; Non-thermal plasma; Ozone; Pulsed corona discharge; Water treatment.

MeSH terms

Electricity
Electromagnetic Phenomena*
Hydrogen Peroxide / analysis*
Hydrogen Peroxide / chemistry
Hydroxyl Radical / analysis*
Hydroxyl Radical / chemistry
Oxidation-Reduction
Ozone / analysis*
Ozone / chemistry
Water / chemistry
Water Pollutants, Chemical / analysis*
Water Purification / methods*

Substances

Water Pollutants, Chemical
Water
Hydroxyl Radical
Ozone
Hydrogen Peroxide