Characterization and comparative evaluation of two atmospheric plasma sources for water treatment

Abstract

A reactor with two interchangeable plasma sources was developed and tested in water decontamination experiments using phenol as model organic pollutant. The two configurations were characterized and compared by determining the reactive species produced in the aqueous phase (concentration of ozone and of hydrogen peroxide as a function of input energy and rate of OH radical production) and the efficiency in phenol degradation. The streamer discharge performed significantly better than the dielectric barrier discharge: the rate of OH radicals production was ten times faster and the efficiency of phenol degradation, as measured by the G50 parameter, was more than twice as large. Moreover, the streamer discharge induced process was kinetically faster and achieved better mineralization yields in shorter times.

Removal of persistent organic pollutants from water using a newly developed atmospheric plasma reactor

“…Hydrogen peroxide instead reached a maximum concentration of 0.5 mM after 800 s of treatment, corresponding to an energy of 4.5 kJ. The profiles of the two species are similar to those observed previously with a similar reactor . Both species are produced and accumulate in solution during the first stages of treatment, then, other reactions, that consume them, prevail.…”

“…It is known from the literature that plasma treatment of phenol in air generates 2‐ and 4‐nitrophenol as byproducts due to side reactions of NO x . Nitrophenols are more toxic and persistent than phenol itself, so their formation is not desirable.…”

“…The elution was followed at 270 nm. The same analyses also allowed for the identification and determination of nitrophenols, which can form as undesired byproducts in air plasma treatment of phenol …”

“…The strategic role of an air plasma based AOP is thus viewed in the context of an integrated water treatment process, as the stage to achieve the degradation of recalcitrant organic pollutants not necessarily all the way to carbon dioxide but to more easily oxidizable TPs. We have recently reported on the efficient AOP of phenol induced by a streamer discharge in air to form a plasma in contact with the phenol solution . The good results obtained with that first prototype encouraged us to further pursue this approach.…”

Characterization of a plasma source for biomedical applications by electrical, optical, and chemical measurements

“…The determination of ozone, hydrogen peroxide, and OH radicals produced in water was done following the procedures reported previously and Eisenberg .…”