Issue
EPL
Volume 86, Number 4, May 2009
Article Number 45001
Number of page(s) 6
Section Physics of Gases, Plasmas and Electric Discharges
DOI http://dx.doi.org/10.1209/0295-5075/86/45001
Published online 04 June 2009
EPL, 86 (2009) 45001
DOI: 10.1209/0295-5075/86/45001

Interaction mechanism between a post-discharge flow and water surface

T. Miyahara1, S. Ochiai2 and T. Sato3

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

sato@ifs.tohoku.ac.jp

received 6 March 2009; accepted in final form 4 May 2009; published May 2009
published online 4 June 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.

PACS
52.77.-j - Plasma applications.
82.33.Xj - Plasma reactions (including flowing afterglow and electric discharges).
52.80.Pi - High-frequency and RF discharges.

© EPLA 2009