Relating atmospheric pressure plasma production of reactive oxygen-nitrogen species to plasma events

Atmospheric pressure plasma production of reactive oxygen-nitrogen species (RONS) has demonstrated potential in various biological applications, such as agriculture. Water in close proximity to these plasmas can absorb RONS and then be applied to plants as fertilizer [1], [2]. In order for plasma production of RONS to be industrially viable, it is important to characterize and optimize this process. Two atmospheric pressure plasma devices are investigated, with differing electrical properties, geometries and plasmaliquid dynamics. The devices are electrically characterized to determine discharge current, dissipated power and plasma events. The concentrations of relevant RONS - nitrate, nitrite, hydrogen peroxide and ammonium - absorbed in plasma treated water are measured colorimetrically. Which RONS and in what proportion differs between devices and can be manipulated. The relation between electrical properties - the frequency and number of plasma events - and the production rate of RONS is investigated. Experiments with deionized water have shown direct correlation between the frequency of plasma events and the production rate of RONS. These results will be used to inform the optimization of the plasma devices with the goal of energy efficiency and high RONS production rate to meet the fertilization demands of growing plants.