Procédé pour l'épuration biologique des eaux résiduaires domestiques suivant le procédé de la boue activée

摘要

In an activated sludge process organic materials are decomposed by means of bacteria in a first aerating stage where a relatively low oxygen-content is maintained. The thus treated water is conveyed to a first sedimentation stage and the effluent from this stage is conveyed in substantially oxygen-free condition to a second aeration stage where bacteriophogic organisms, usually protozoa, are maintained under optimum conditions of relatively high oxygen-content. Biologically purified water is obtained from a second sedimentation stage.