Evaluation of Energy-Conversion Efficiency of Multineedle-to-Plate Corona-DBD Plasma for Organic Degradation in Soil

In this paper, energy-conversion efficiency (
$\eta $
) of multineedle-to-plate corona-dielectric-barrier discharge (DBD) at atmospheric pressure was investigated for the application of degradation of organics in soil. Discharge current characteristics with applied voltage were measured. The factors contributing to
$\eta $
included applied voltage, discharge frequency, multineedle electrode, and dielectric.
$\eta $
increased with the applied voltage and resonant frequency generated the highest
$\eta $
value. The number of needles and the variable distance between every two needles for the high-voltage electrode both had influence on
$\eta $
. The examination of
$\eta $
was also performed for the dielectrics characterization investigated. In order to facilitate the evaluation of the contribution of corona-DBD plasma to the remediation of organic-contaminated soil, p-nitrophenol (PNP) was used as target. Up to approximately 80% degradation was observed for PNP in soil exposed 3 mm away from the multineedle electrode. The plasma that remediated the soil sample with higher PNP concentration exhibited more efficient for the conversion of the electric energy.