Abstract: An agitator for agitating liquids in an agitator vessel for suspending solids and dispersing gas in a liquid, in particular in an absorber of a flue gas desulfurizing plant, includes an agitator vessel, an agitator shaft extending into the agitator vessel, and an agitating propeller mounted to the agitator shaft within the agitator vessel. The agitator shaft is hollow to define an interior space for conducting gas into the agitator vessel and injecting gas on the pressure side of the agitating propeller into the liquid.

Abstract: In a process for the treatment of water with ozone a partial current of treated water is contacted under pressure in a packed column with an oxygen-ozone mixture from an ozonizer to oxidize water contaminants and to improve their flocculation. The portion of oxygen which has not dissolved in the water in the packed column is recycled into the ozonizer and the treated partial water current is mixed again with water to be treated. The pressure in the column is adjusted in dependence on the nitrogen content of the water to be treated. By this measure is ensured that the quantity of nitrogen escaping from the water and contained in the cycle oxygen permits an optimum operation of the ozonizer. The nitrogen content in the cycle oxygen is preferably kept below 10% by volume.