Comparison of relative concentration of ozone and oh radical produced in discharge space with water droplets


Taichi Sugai
Weihua Jiang
Akira Tokuchi


We have studied a water treatment by spraying into a pulsed discharge space in air. OH radical produced by the discharge decomposes refractory organic compounds because of its high oxidizing power. The well-known process of OH radical production is dissociation of water molecule by electron collision. However, we expect almost all OH radicals are produced via reactions including ozone. To confirm it, relative concentrations of ozone and OH radical, reacting with organic compounds were measured using the indigo method and a florescence method using the disodium salt of terephthalic acid (NaTA), respectively. The measurements were carried out regarding pulsed discharge of repetition rate of 17 and 300 pulse per second. Concentrations of ozone and OH radical increased by higher repetition rate. However, energy yields for those production decreased by higher repetition rate. A possible reason is the increase of decayed ozone. This result shows the possibility that OH radical is produced by the reaction with ozone.


How to Cite
Sugai, T., Jiang, W., & Tokuchi, A. (2017). Comparison of relative concentration of ozone and oh radical produced in discharge space with water droplets. Power Research - A Journal of CPRI, 131–134. Retrieved from


  1. Y. Minamitani, S. Shoji, Y. Ohba and Y. Higashiyama, “Decomposition of dye in water solution by pulsed power discharge in water droplets spray”, IEEE Trans. Plasma Sci.,., Vol. 36, No.5, pp. 2586-2591, 2010.
  2. T Sugai, A Tokuchi, W Jiang, and Y Minamitani, “Investigation for optimization of an inductive energy storage circuit for electrical discharge water treatment”, IEEE Trans. Plasma Sci., Vol. 42, No. 10, pp. 3101-3108, 2014.
  3. T. Sugai, P. T. Nguyen, A. Tokuchi, W. Jiang, and Y. Minamitani, “The effect of flow rate and size of water droplets on the water treatment by pulsed discharge in air”. IEEE Trans. Plasma Sci., Vol. 43, No.10, pp. 3493-3499, Jan. 2015.
  4. T. Nose, Y. Yokoyama, A. Nakamura, and Y. Minamitani, “Effect of oxygen gas on the decomposition of dye by pulsed discharge in water droplet spray”, Electrical Engineering in Japan., Vol. 183, No.4, pp.648-658, 2013.
  5. K. Chelkowska, D. Grasso, I Fábián and G. Gordon “Numerical simulations aqueous ozone decomposition”, Ozone Sci. Eng., Vol. 14, No. 1, pp. 33–49, 1992.
  6. H. Bader, J. Hoigné, “Determination of ozone in water by the indigo method”, Water Research, Vol. 15, pp. 449–456, 1981.
  7. S. Kanazawa, T. Furuki, S. Akamine and R. Ichiki, “Measurement of OH radicals in aqueous solution produced by atmosphericpressure LF Plasma jet”, International Journal of Plasma Sci. and Tech., Vol. 6, No. 2, pp. 166-171, 2012.