Single stage process for continuous introduction of oxygen-containing gases into effluent containing activated sludge

Abstract

A process and apparatus for the continuous introduction of air or oxygen-containing gases into an effluent containing activated sludge, the oxygen-containing gas largely being consumed by the effluent containing activated sludge in a single absorption stage, comprising introducing through a plurality of gas inlets an oxygen-containing gas into an effluent containing activated sludge which is in a basin under its own hydrostatic pressure of at least about 0.9 bar, the gas pressure of the gas introduced being about 0.01 to 0.5 bar above the hydrostatic pressure prevailing at the gas inlet, each gas inlet having a gas-swept cross-sectional area of at least about 0.01 m.sup.2 which is loaded by at least about 100 effective cubic meters of gas per square meter of cross-sectional area per hour, and the individual gas inlets being separated by a distance of at least about 0.5 meter, as measured from the middle point of a gas inlet. The gas inlets may be nozzles, ejectors or apertured plates preferably spaced equidistantly from one another and each may be supplied with propulsion liquid comprising effluent containing activated sludge. Preferred ranges from the various parameters depend upon whether the gas introduced contains more or less than 50% by volume of oxygen. Special gas injectors are also provided.

Dependencies are inferred from the claim text.