Optimization of process parameters to generate plasma activated water and study of physicochemical properties of plasma activated solutions at optimum condition

Abstract

Plasma-activated water (PAW) is gaining significant attention these days due to its potential use as a disinfectant, pesticide, food preservative, cancer cell treatment, fertilizer, etc. These applications of PAW depend on its reactivity (oxidizing-potential) and electrical conductivity (EC). In the present work, we have studied the effect of process parameters, viz., air flow rate, water stirrer speed, and the temperature of water during plasma–water interaction on the reactivity and EC of PAW using a three-way full factorial design of experiments. We have also attempted to optimize these process parameters. At optimum values of these parameters, we studied how the physicochemical properties of PAW vary by changing the volume of water and discharge power. Furthermore, we studied the physicochemical properties of the plasma-activated solution (PAS) and how the EC and pH of virgin solutions affect these properties. The obtained results of the present investigation showed that the flow rate of air, plasma treatment time with water, volume of water, and plasma discharge power play a significant role in controlling the reactivity and EC of PAW. Moreover, the pH and EC of virgin solution do not have a significant (p < 0.05) impact on the reactivity of PAS. This investigation also shows the study of aging time on reactive oxygen–nitrogen species and its effect on the physicochemical properties of PAW. Additionally, observed changes in physicochemical properties, NO3− ions, and H2O2 concentration in PAW were less than 10%. However, NO2− ions and dissolved O3 concentration in PAW decreased significantly over time.

Nanosecond‐pulsed microbubble plasma reactor for plasma‐activated water generation and bacterial inactivation

“…[43][44][45][46][47] The oxidation-reduction potential (ORP) represents the net combination of oxidizing species such as NO 3 − , NO 2 − , H 2 O 2, and Ozone dissolved in the PAW. [48] Figure 7 shows the changing trend of ORP at different treatment times and temperatures. Figure 5a-c shows that with the increase of treatment time, all the concentrations of NO…”

Effect of Plasma-Activated Water Bubbles on Fusarium graminearum, Deoxynivalenol, and Germination of Naturally Infected Barley during Steeping

“…Also, treatment D had higher pH and lower ORP compared to other treatments which were due to weaker plasma in treatment D and the higher amount of water used in this treatment. The increase in ORP was likely due to an increase in the concentration of active ions and oxidizing species such as H 2 O 2 , HNO 3 , HNO 2 − , and O 3 in PAW bubbles [ 7 ]. It should be noted that pH affects the ORP; in acidic pH, hydrogen ions (H + ) increase the ORP, whereas in alkaline pH, hydroxide ions (OH − ) decrease the ORP value [ 8 ].…”

“…H 2 O 2 was formed mainly from water decomposition and subsequent recombination of • OH radicals (reaction 7) [ 16 ]. Due to reactions 1 and 3, the concentration of H 2 O 2 was also reduced during storage [ 7 ]. Reactions 2, and 3 could also be the reason for the decrease in the concentration of NO 2 − during storage.…”

“…The physicochemical properties of PAW are largely affected by the plasma power supply and production system, configuration of electrodes, treatment time, type of working gas, process parameters such as voltage and frequency, gas flow rate, etc. [ 7 ].…”

Penicillin Antibiotic (Ampicillin and Cloxacillin) Degradation Using Non-Thermal Pencil Plasma Jet

“…The measured reactive oxygen-nitrogen species (RONS) due to plasma-water interactions were nitrate (NO 3 ‾) ions, nitrite (NO 2 ‾) ions, hydrogen peroxide (H 2 O 2 ), and dissolved O 3 . The method of determination of these physicochemical properties and RONS concentration were discussed in our past literature (30)(31)(32)(33).…”