Characteristics of an Underwater Plasma Source with a Porous Glass Membrane

Abstract

SUMMARYThe advanced oxidation process (AOP) with hydroxyl radicals (OH) is considered to be useful for water purification through oxidation; therefore, we proposed an underwater plasma source with a porous glass membrane which performed the functions of bubble supply and the formation of microdischarges. We observed bubble formation and light emission from discharges on the surface of the membrane using a high-speed camera and a spectroscope, respectively. In addition, the dependence of gas pressure on the generation of OH radical and the decomposition of recalcitrant organic matter were examined. The obtained results showed that AOP may be more effective when the operating gas pressure is set higher than a pressure which could form bubbles. C⃝

Characteristics of Underwater Plasma with Surfactant

“…2 However, ozone-based water treatment has not been widely adopted in many countries for some reasons, such as low treatment efficiency due to poor water solubility of ozone, or inability to decompose persistent organic substances including surfactants. 3 Thus, there is a need to improve efficiency of treatment and to decompose persistent organic compounds. In this context, attention is drawn to advanced oxidation processes using OH radicals that outperform O 3 in oxidation potential.…”

Characteristics of underwater plasma with surfactant

“…Oxidation power of ozone in water is about seven times as high as that of chlorine, and ozone is appreciated for its performance in terms of water sterilization, deodorization, and decoloration . However, ozone‐based water treatment has not been widely adopted in many countries for some reasons, such as low treatment efficiency due to poor water solubility of ozone, or inability to decompose persistent organic substances including surfactants . Thus, there is a need to improve efficiency of treatment and to decompose persistent organic compounds.…”