METHOD OF INTRODUCING OXYGEN OR GAS CONTAINING OXYGEN TO SUMP SOLUTION AND ITS DEVICE

In activated sludge-containing wastewater from sewage treatment plants, oxygen is absorbed and consumed. Oxygen-containing gas, having at least 50% by volume of O2, at a hydrostatic pressure of 0.9 to 4 bar is passed in to a wastewater tank (10). The liquid height in the clarification tank (10) is 10 to 40 m. The gas pressure is 0.01 to 0.5 bar above the hydrostatic pressure at the gas introduction positions (12, 14), each of which has an aerated surface of 0.1 to 0.5 m . Each gas introduction position (12), which is a bundle of a plurality of injectors, ejectors or nozzles or an orifice plate, is charged with 100 to 300 effective cubic metres of gas per m of cross-sectional area and hour. The individual gas introduction positions (12) have a mutual central spacing of 2 to 10 m. The process permits the optimal utilisation of oxygen with single-stage operation.