Analysis of Mechanisms at the Plasma–Liquid Interface in a Gas–Liquid Discharge Reactor Used for Treatment of Polluted Water

Abstract

Aqueous solutions polluted by contaminants different from those generally studied (phenol and chlorophenols) were treated in a falling film gas-liquid dielectric barrier discharge reactor. The lower was the Henry's law constant of a molecule, the better was its removal percentage, regardless of its other chemical properties. In the case of saturated molecules, the removal mechanism is the transfer of pollutants from the liquid phase to the gas phase where they react with the active species of the discharge. For phenol, the reaction with ozone in the liquid phase was estimated to be responsible of about 30% of the removal. A computational fluid dynamic modelling provided a better understanding of the phenomena, indicating that mass transfer of pollutants from liquid to gas is accelerated due to (1) the intense mixing in the liquid film and (2) the reaction of the pollutant with the active species in the gaseous phase.

Non-aqueous phase liquid-contaminated soil remediation by ex situ dielectric barrier discharge plasma

“…During the last years, the non-thermal plasma discharge (NTP) has been considered as a well-promising advanced oxidation process (AOP) and is used as an energetically efficient method of wastewater treatment (Locke et al 2006;Hao et al 2007;Zhang et al 2008;Ognier et al 2009;Qu et al 2009). Additionally, NTP has extensively been studied for the treatment of polluted gases and has been used successfully for the removal of various hydrocarbon pollutants such as aliphatics, aromatic compounds, aromatic polycyclic compounds and halogenated solvents (Masuda 1988;Mok et al 2002;Kim 2003;Lee et al 2004;Kim et al 2005;Bai et al 2009).…”

Application of Dielectric Barrier Discharge for Waste Water Purification

“…Discharges where plasmas can come in direct contact with the solution are the most attractive because in this case it is possible to use the most part of plasma active species more completely. Different types of discharges and setups have been used for these purposes including discharges with one or two liquid electrodes [1][2][3], pulse positive streamer corona discharge generated in aqueous solutions [4,5] and dielectric barrier discharge (DBD) [6][7][8].…”

Characterization of plasma-induced phenol advanced oxidation process in a DBD reactor

“…There is currently much ongoing research to exploit and apply electrical discharges for water purification [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Many different prototype reactors have been developed, including systems in which the discharge occurs into [2][3][4][5] or above the liquid [6][7][8][9], as well as hybrid reactors, which utilize both gas phase non-thermal plasma and direct liquid phase corona-like discharge in the water [10,11].…”

“…Many different prototype reactors have been developed, including systems in which the discharge occurs into [2][3][4][5] or above the liquid [6][7][8][9], as well as hybrid reactors, which utilize both gas phase non-thermal plasma and direct liquid phase corona-like discharge in the water [10,11]. In addition reactors have been reported in which the solution to be treated is supplied into the discharge area as an aerosol [12] or as a falling-water film [13,14].…”