DC Discharges with Water and Their Applications

Abstract. Two types of DC electrical discharges in atmospheric air (streamer corona and transient spark) were tested for decontamination and decoloration of water contaminated by bacteria and organic dyes. The flowing water passed through the high voltage (HV) needle electrode into the active discharge region. The bacteria were killed most efficiently by transient spark and streamer corona with lower flow rates. The decoloration effect was the most expressive for water treated by transient spark. The effect of electrospraying of water (EHDA) was observed when using streamer corona discharge. This effect was also investigated in more details. Different modes of EHDA were observed deppending on the applied voltage. Presence of 2 current pulses with different frequencies were observed. Using various HV electrodes, water flow rates and inter-electrode spaces also lead to different results.