Abstract: A method and energy-efficient apparatus for the treatment of liquids through the joint use of a gas mixture-oxidizing agent and UV radiation. This method uses an excimer UV lamp performing two actions affecting the liquid and changing its properties with UV radiation and the generation of a gas mixture containing strong oxidizing agents for influence on the liquid, disinfection and purification of the liquid being treated from contaminants. The apparatus incorporates energy efficient design features to reduce energy consumption and operational costs, as well as an excimer lamp design that improves performance parameters to surpass and outlast existing devices. Unique electrode designs, cleaning systems, and materials combine to create a state-of-the-art liquid treatment apparatus that exceeds existing industrial analogs and norms.