A method and apparatus are provided for cleaning a surface. In one example, the method includes passing a feed liquid from a liquid source to an electrolysis cell and inducing a current through the electrolysis cell to electrochemically activate the feed liquid in the electrolysis cell. Electrolysis of the feed liquid can generate an electrochemically-activated liquid that is super-saturated with dissolved gases (e.g., oxygen and/or hydrogen) and also contains nanobubbles. In one configuration, the electrolysis cell generates a concentration of nanobubbles having a diameter of 10 nm to 450 nm of at least 1×106. The method can further involve dispensing at least one portion of the electrochemically-activated liquid to the surface.