Selective control of reactive nitrogen and reactive oxygen species in a DBD plasma source *

Plasma activation of water has a host of applications ranging from fertilization of crops to the treatment of diseased tissue.  Activated water is considered an indirect plasma treatment method with the active solution having a long shelf or half-life compared to the typical treatment times. For certain applications such as wound healing, higher reactive nitrogen species content is desirable. For other applications the such the washing of fruit or drinking water, it its desirable to control the nitrate concentration.  We present here a plasma source that features variable flow chemistry that allows the ratio of nitrates/nitrites to reactive oxygen species concentration to be varied, thereby allowing for process optimization. This source was developed for the treatment of surfaces containing viral particles such as COV-19 or bacteria.  Control of activated water quality is desirable if one is treating food surfaces and utensils for example or sensitive fabrics.  RNS/ROS ratios versus input power and input flow conditions and input power are presented along with disinfection trial data.