A Method of Cyanobacteria Treatment Using Underwater Pulsed Streamer-Like Discharge

Water bloom (named cyanobacterial bloom) is becoming a serious pollution problem all over the world. In this paper, a method of cyanobacteria treatment using underwater streamer-like discharge 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 streamer-like discharge 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 conducted the experiment at a dam in Kyushu district in Japan. We have measured chlorophyll concentration, turbidity, potential of hydrogen, dissolved oxygen, conductivity, and temperature of water during treatment of cyanobacteria bloom. The treatment time is 60 min. All of them could be reduced. In particular, the chlorophyll concentration and the turbidity are remarkably decreased. Initial chlorophyll concentration is 600 μg/L, and initial turbidity is 1000 nephelometric turbidity unit (NTU). We obtained that treatment results of chlorophyll concentration and turbidity were 85 μg/L and 80 NTU, respectively.