Development of water treatment system using nanosecond pulsed powers to treat surfactant

Water Pollution is one of nontrivial environment issues around the world. Consumption of surfactants instead of organic solvent has increased for industrial and domestic usages, but the surfactants have environmental load. We have studied a water treatment using nanosecond pulsed powers. Discharge plasmas generated by the nanosecond pulsed powers efficiently produce radicals, as ozone, which are applicable to water treatments. The water treatment by nanosecond pulsed power uses actions of not only radicals but also discharges. A water treatment system was developed to increase radical density and activate the action of discharges. In addition to use of nanosecond pulsed powers, a dielectric barrier in electrodes was adopted for the system to decrease electrode separation in the reactor. When oxygen gas was used as ambient gas of discharges, surfactant in solution would decompose. On the other hand, indications were not found that the treatment in nitrogen gas decomposed the surfactant in these experiments. Although chemical oxygen demand (COD) of the surfactant solution was not correctly evaluated owing to melted oxygen gas in solution, the indication of decomposition of surfactant was found in the other experimental results.