Investigation of optimum pulse width of appled voltage for water treatment by pulsed streamer discharge in air spraying water droplets

We have studied the water treatment method of spraying the droplets of waste water into a pulse discharge space. In this method, we have been developing the pulse generator which realizes higher treatment efficiency. For that, the investigation of an optimum applied voltage from the pulse generator for the treatment is needed. In this paper, investigation of an optimum pulse width has been carried out by applying the voltage of different pulse widths. As sample water for the investigation, indigo carmine solution was used. The pulse widths of applied voltage was 40, 60 and 80 ns, and Those rise time was 12, 19 and 32 ns, respectively. By the water treatment of the pulse width of 40 ns, indigo carmine was decomposed at lower energy than that of the other pulse width. From the result, generating of active species is considered to increase in early time of the discharge and to decrease with development of the discharge. Therefore it is expected that shorter pulse width realize higher treatment efficiency.