A liquid stream is transformed into a vapor and liquid medium, then plasma state is generated in the medium, which generates various high-energy particles causing a number of physical and/or chemical effects, then the vapor and liquid medium is condensed back into an output stream of liquid. Liquid feedstock (e.g. water) is nebulized using pressure drop and/or acoustic waves within a chamber, then an electric field exceeding the breakdown voltage threshold of the nebulized medium is applied to the medium, thus igniting plasma state. At the exit of the chamber, the nebulized medium is transformed back into liquid state. Liquid treatment with plasma state applications are thus enabled with high versatility and control in igniting and maintaining a plasma state at a cost-effective level of energy consumption.
