Study of water treatment by using underwater pulsed discharge plasma

Summary form only given. Recently, study of environmental applications such as water treatment using a pulsed power is increasing. Water-bloom (named as cyanobacterial bloom) is becoming a serious pollution problem all over the world. In this study, a method of cyanobacteria treatment using underwater pulsed discharge plasma is reported. Repetitive underwater discharges are generated by all solid-state pulsed power system. Output voltage of the pulsed power system is 30 kV with 4 μs pulse width. We can generate repetitive underwater pulsed discharge plasma by the pulsed power system. And we have the system mounted in the Water-bloom treatment apparatus. The size of streamer-like discharge is about 30 mm diameter. We were experiment at dam of Kyushu district in Japan. We have measured chlorophyll concentration, turbidity, potential of hydrogen (pH), dissolved oxygen (DO), conductivity and temperature of water during treatment of cyanobacteria bloom. The treatment times are 60 minutes. All of them could reduce. In particular, the chlorophyll concentration and the turbidity are remarkable decreased. Initial chlorophyll concentration is 600 μg/L, and initial turbidity is 1000 NTU. We obtained that treatment results of chlorophyll concentration and turbidity were 85 μg/L and 80 NTU respectively.