Experimental Investigation for the Generation and Characterization of Plasma-Activated Water

This article represents the generation of plasma-activated water (PAW) through a developed atmospheric pressure cold plasma jet source using air and powered by a short pulse power supply (7 kV/25 kHz/ $1~\mu $ s). The water sample having high total dissolved solids (TDSs) is treated by inserting a 10 mm plasma jet into the water surface. The generated PAW is analyzed mainly by evaluating nitrate, nitrite, oxidation-reduction potential (ORP), TDS, electrical conductivity (EC), and pH. The results clearly illustrate an increase in the concentration of nitrate, nitrite, and ORP for an increase in cold plasma treatment time from 3 to 15 min. The maximum nitrate concentration of 155 ppm has been obtained in the water (TDS ~1000 ppm) for 15 min of cold plasma treatment. The pH concentration of the generated PAW remains almost constant. The generated PAW has also been tested for its suitability in germination enhancement and plant growth. The results noticeably indicate higher germination rate, vigor index, length, and weight of root and shoot of seeds irrigated with PAW as compared to tap water. The fungal growth in PAW irrigated seed saplings is also negligible than that of tap water irrigated seeds in 15 days of continuous observation period. This study would be very useful for the design and development of PAW systems for water samples with high TDS for agriculture applications.