Liquid aspirator for drawing off and sucking up liquids, having a drawing-off lip, having a suction device for sucking up the liquid into a separating space in the housing of the liquid aspirator, having an exhaust-air channel, which is subjected to a negative suction pressure and is intended for leading the air out of the separating space, having a separating device, which is arranged in the separating space and separates the liquid from the water, and having a tank for accommodating the liquid. Complex guidance of the liquid/air stream is avoided in that the housing has a hollow chamber which forms the separating space and the tank, and into which the intake channel opens and from which the exhaust-air channel is guided out of the housing; wherein the hollow chamber contains a motor-driven rotor with a rotating impact surface, and the intake channel is designed such that the air/liquid stream is directed for radial direction reversal and acceleration onto the impact surface.