細管内スパーク放電照射プラズマ処理水の成分経時変化における細管径依存性

In recent years, research on the application of plasma treated water to agriculture or medicine has been actively carried out. For further application of plasma-treated water, it is desirable to understand the reaction process and to prepare plasma-treated water of arbitrary rate and concentration. In this study, the plasma treated water prepared by spark discharges in capillary quartz tubes were investigated. The diameter of the capillary tube was changed from 1.0 mm to 3.5 mm, and the change over time of concentrations of NO2-, NO3-, H2O2, and pH were investigated. It was found that the rate of increase in NO2- was suppressed as the diameter of the capillary tube decreased. As a result, the treatment time at pH = 4.6, the treatment time when NO3- starts to increase, and the treatment time when H2O2 starts to decrease, were increased. The reason for the decrease in the rate of increase in NO2- was considered that the generation of NO2 around the plasma was suppressed as the diameter of the capillary tube decreased, and NO2 was less dissolved in water.