Nutrient Removal: Experiences in Johannesburg (Abridged)

The ability to remove nitrogen and phosphorus by biological means in the activated‐sludge process represents the most significant refinement of the process since its discovery. This paper reviews the development of the activated‐sludge process in Johannesburg. Emphasis is placed on the last twenty years’research into biological nutrient removal and the successful incorporation of research findings into the design and operation of full‐scale plants of up to 200 Ml/d capacity.