[en] Decomposition of dichloromethane (DCM) by discharge inside bubble in water is investigated. A gas injected discharge reactor is employed to achieve degradation with high energy efficiency. The reactor consists of a glass tube and a tungsten wire inserted into the glass tube, which is immersed in the water. The nanosecond pulsed high voltage generated by an inductive energy storage system pulsed power generator is applied to the tungsten wire to generate streamer discharge. Argon gas is injected into the glass tube to generate bubbles in the water. The experimental result shows that total organic carbon (TOC) and pH value decrease and chloride ion concentration increases by the discharge treatment. DCM is volatilized into the bubble, which is decomposed by hydroxyl radical produced by the discharge. (author)