Process and device for purifying wastewater

摘要

The method purifies waste water in a series of stages. In the first, (A) it is aerated and in the second, which also includes sludge recycle, intermediate settlement takes place. If appropriate, further aeration occurs in the third stage (C), with final sedimentation in a fourth stage. In this original process, the reaction is influenced in an initial anaerobic stage, whilst the residence time is varied by volume alteration.