Dynamics of Long‐Lived RONS and Peroxynitrous Acid ONOOH in Water Treated By Nanosecond Discharges

ABSTRACT The dynamics of long‐lived reactive oxygen and nitrogen species (RONS) in plasma‐activated water (PAW) are studied. The water is treated by nanosecond discharges generated between a piezoelectric transformer and the water surface. Сoncentrations of the species (H 2 O 2 , HNO 2 , NO 2 − , NO 3 − ) are measured in situ using UV absorption spectroscopy. Changes in species concentrations during the post‐treatment period are mainly due to the oxidation reaction of HNO 2 by H 2 O 2 (+ H + ) to produce HNO 3 and the short‐lived intermediate peroxynitrous acid ONOOH. During water treatment, the production rates of H 2 O 2 and HNO 2 (the sum of HNO 2 and NO 2 − ) are equal. This suggests that they may be formed in the same reaction or chain of reactions.