Large-scale activated sludge plant for biological waste water treatment

摘要

Waste water is to be biologically purified in a round aeration tank or in a long aeration tank having rounded ends and a plurality of adjacent aeration tank sections, with the use of circulating aerators (13,14). These aerators (13,14) are arranged to be moveable over the tank base (1) and are connected to an aeration bridge (7) rotating above the tank or the tank sections (I,II). In order to keep the energy consumption required for the aeration bridge (7) drive as low as possible, a support shaft (5) is arranged in the centre of the tank or in each tank section (I,II), on which shaft is provided on a support (6), above the water surface (20), a two-armed aeration bridge (7), freely projecting on both sides, which can be rotated by means of a motor drive. By means of the avoidance of any supports of the aeration bridge (7) on the surrounding wall (2), the friction resistance of the aeration bridge to rotation is markedly reduced, thus making significant energy savings possible.