[15p-PB2-1~53] 8 Plasma Electronics（Poster)

[15p-PB2-10] Decomposition of Agrichemicals and PFOA in Solution using Flow-through Type In-liquid Plasma

〇Takeshi Ishida¹, Yoshinobu Kohara¹, Kimiyoshi Koda² (1.Hitachi, R&D Group, 2.Hitachi High-Tech Science)

Keywords:Organics,Decomposition,In-liquid plasma

we proposed a novel technique for organics decomposition in solution using flow-through type in-liquid plasma (FLP). FLP is a micro-plasma caused by high-voltage discharge in a micro-channel, enables highly-effective decomposition in flow-through manner. Since the vessels and plasma source gas are not required, small and on-site apparatus can be realized. FLP originate from liquid electrode plasma and its principle is as follows. A liquid sample with electrolytes is filled inside a flow cell having narrowed channel and then high-voltage DC pulse is applied with electrodes on both sides of the flow cell. As a steam bubble generated by Joule heating at the narrowed center part expands and blocks the current path, the applied voltage is focused on the bubble. Then the bubble-liquid interfaces work as liquid electrodes for discharge inside the bubble. This discharge accompanies micro-plasma which generates chemical active species including OH radicals. We evaluated decomposition rate of organic dye as model substances and acetic acid as model of persistent organics previously. In this work, we evaluated decomposition rate of agrichemicals as model of hazardous organic compounds, and perfluorooctanoic acid (PFOA) as model of persistent organic pollutants (POPs).