Investigative Study on the Interaction and Applications of Plasma Activated Water(PAW)

Abstract

Cold plasma is a budding technology that can be used as a nonthermal disinfectant and for surface modification which is free of chemicals and is environmentally friendly. The treatment of water with plasma, producing plasma activated water (PAW), generates an acidic condition resulting in the formation of reactive oxygen species (ROS), reactive nitrogen species (RNS), and creates change in the redox potential as well as conductivity. Consequently, the chemical composition of water and PAW differ from each other and can now be employed as a substitute for disinfection against microbes. The various sources of plasma used for PAW production, its physical and chemical properties and its prospective uses are reviewed in this paper. Particularly, the physiochemical properties of PAW will be discussed in the context of its acidity, conductivity, the amount of ROS and RNS, as well as its redox potential. Since the results are microbial in nature, the microbial disinfection with the use of PAW will also be reviewed. Lastly, the usage of PAW to enhance agricultural methods, such as its effect in plant growth and stimulating seed germination, is also discussed. It can be interpreted that PAW synergistically disinfects food as well as enhances the growth of seedlings. The boost in plant growth conceivably be mainly due to the increase in concentration of nitrate and nitrite ions in PAW. Therefore, in addition to the antimicrobial action of PAW, submerging seedlings in PAW supplements the germination of seeds and plant growth. This could possibly help fight against the drought stress and improve the yield of crops.

Comparison of the Effect of Plasma-Activated Water and Artificially Prepared Plasma-Activated Water on Wheat Grain Properties

“…Their abundance and representation depend strongly on the experimental conditions of PAW preparation, including the arrangement of the production discharge and the composition of the working gas. Many authors, e.g., [ 28 , 29 , 30 , 31 , 32 ], have described the properties of PAW. The advances in the methods for preparing PAW and monitoring its properties, as well as some of its practical applications, were recently reviewed by [ 33 , 34 , 35 ].…”

Effects of Non-Thermal Plasma Treatment on Seed Germination and Early Growth of Leguminous Plants—A Review

“…In addition, the described effects are not constrained to the direct NTP treatment, but on a lower scale are also mediated by the effects of plasma-activated water (PAW) or air, i.e., the water exposed to NTP prior to the application to desired objects. The described effects can persist for many months after exposure, mainly due to the presence of stable reactive oxygen and nitrogen particles as described e.g., in [ 28 , 29 , 30 ].…”

A Review of Microbial Decontamination of Cereals by Non-Thermal Plasma

“…Recently, the phenomenon of so-called plasma-activated water or plasma-treated water has also been described, where NTP is applied only to pure water or other medium [ 42 , 43 , 44 ]. Active particles mediate the desired properties, although they accumulate to a lesser extent than in direct action.…”