Phenol Degradation in Ground and Distilled Waters under the Action of Cold Plasma of Nanosecond Discharges in Air

The indicators of phenol degradation in ground and distilled waters treated by plasma of nanosecond discharges in air, both when the plasma was applied above the solution surface and when the solution was sprayed into the active discharge zone, have been determined. It was found that phenol degrades much less effectively in groundwater than in distilled water. The best results of phenol degradation at the same discharge power were obtained by treating the solution with plasma above its surface, rather than in an air-droplet mixture, which was contrary to expectations. It has been shown that the duration of the discharge, rather than its intensity, is the more significant factor. Thus, the degree of phenol degradation in groundwater with a volume of 100 mL reached 92% at a voltage pulse repetition rate of 100 Hz, 1 300 000 pulses (3.6 h), and discharge power of 2.6 W. Energy yield was 171 mg/kWh. Recommendations are given for further increasing the efficiency of degradation of organic pollutants using pulsed high-voltage discharges.