Production characteristics of reactive oxygen/nitrogen species in water using atmospheric pressure discharge plasmas

Abstract

Abstract A pulsed discharge, a DC corona discharge, and a plasma jet are separately generated above a water surface, and reactive oxygen species and reactive nitrogen species (ROS/RNS) in the water are investigated. ROS/RNS in water after the sparging of the off-gas of a packed-bed dielectric barrier discharge (PB-DBD) are also investigated. H 2 O 2 , NO 2 − , and NO 3 − are detected after plasma exposure and only NO 3 − after off-gas sparging. Short-lifetime species in plasma are found to play an important role in H 2 O 2 and NO 2 − production and long-lifetime species in NO 3 − production. NO x may inhibit H 2 O 2 production through OH consumption to produce HNO 2 and HNO 3 . O 3 does not contribute to ROS/RNS production. The pulsed plasma exposure is found to be effective for the production of H 2 O 2 and NO 2 − , and the off-gas sparging of the PB-DBD for the production of NO 3 − .