Inactivation of algae in ballast water with multi-needle gas-liquid hybrid discharge reactor

Pulsed high-voltage discharge is a new advanced oxidation water treatment technology. Plasma technology has recently become significant because it offers the advantages of lower costs, higher treatment and energy efficiencies, and the smaller space volume it occupies. The present work investigates the use of a multi-needle plate reactor with gas-liquid hybrid discharge system to sterilize ballast water. The optimal sterilization parameters of the reactor such as plasma treatment time, pulsed voltage, pulsed frequency, and distance between the water level and the needle tip were chosen for testing was a variety of parameter values. The algae contaminated ballast water was treated by the pulsed high-voltage discharge plasma. The sterilization rate was increased with the increase in treatment time, peak voltage and pulse frequency. In this experiment, four kinds of algae (Chrysophyta spp., Nitzschia closterium f.minutissima, Platymonas spp., and Chlorella spp.) were treated with 185 needle electrodes. The results show that the multi-needle plate reactor has a good sterilization effect on almost all of the algae in ballast water.