Abstract
Recent researches on plasma-liquid interface are introduced. One is about plasma-water interaction at the interface of pulsed dielectric-barrier plasma in gas-liquid two-phase flow for water treatment. Acetic acid in water is decomposed as a persistent material. Numerical calculation indicates that plasma-water interaction which is O-radical-induced generation of liquid-phase-OH radical occurs. The other reports highly-concentrated adsorption of a surfactant at plasma-water interface, and an interfacial reaction decomposing the surfactant. Perfluorooctane sulfonic acid is an extremely persistent surfactant, but can be decomposed by plasma attached to the solution. The decomposing reaction occurs at the plasma-water interface. Estimation of the amount of PFOS adsorbing to the plasma-water interface shows much higher mole fraction of PFOS than that in bulk water. Thus, the plasma can effectively react with PFOS at the water surface and exhibits high energy efficiency.