Intensification of the activated-sludge process (abridged) - Discussion

During the last thirty years, attempts have been made to increase the rate of treatment of wastewater in compact activated-sludge systems whilst ensur ing (a) an adequate supply of dissolved oxygen, (b) good settleability of a ctivated sludge, and (c) consistently high-quality effluents. This paper describes two successful systems, i.e. oxygenated activated slud ge and the deep-shaft process, which ape used to intensify the rate of trea tment in relatively compact aeration tanks. Data are presented of full-scal e oxygen activated-sludge systems, including Vitox and Unox, together with information on the operation and performance of the deep-shaft process.