Interaction mechanism between a post-discharge flow and water surface

¹  Faculty of Engineering, Shizuoka University - 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8561, Japan
²  Graduate School of Engineering, Tohoku University - 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
³  Institute of Fluid Science, Tohoku University - 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan

Corresponding author: sato@ifs.tohoku.ac.jp

Received: 6 March 2009
Accepted: 4 May 2009

Abstract

The interaction mechanism between a post-discharge flow and the water surface was studied by focusing on the generation and residual of reactive oxygen species (ROS) in purified water. Exposure of a water surface to a post-discharge flow at atmospheric pressure for 10 min generated ROS in purified water. The ROS concentration increased by approximately 20 times with 43% of the ROS still remaining after 30 min in air, whereas exposure only to the plasma emission did not affect the level of ROS in purified water. Correspondingly, the pH of the former water decreased from 6.49 to 4.84 during the exposure period. The ROS in the former water has a weak bacteriostatic effect.