Investigation for development of high efficiency water treatment system using pulsed streamer discharge

Water treatment using pulsed streamer discharge in water has been studied currently. We have attempted to develop high efficiency water treatment system for a practical application. The system is composed of a reactor module and a pulsed power generator. Initially, an investigation of the pulsed power generator is described. An inductive energy storage circuit and a capacitive energy storage circuit, with semiconductor switches and magnetic switches were compared. The IES circuit could output higher voltage than that of the CES circuit, but the energy efficiency was lower than that of the CES circuit. However, the IES circuit realized the higher voltage output and the high energy transfer efficiency by the adjustment of the load impedance. Then, an investigation of structure of the reactor module is described. Three water treatment methods, i.e., discharge on water surface, discharge in bubbles in water, and water droplets spray into discharge space in gas, were compared. For the water droplets spray type, the energy efficiency for the decomposition of acetic acid was not the highest although that for dye is the highest. To increase the energy efficiency for the acetic acid, the discharge energy density should be low and a kind of gas in which the discharge is generated should be investigated.