Automatic Dissolved Oxygen Control

A manual describing design procedures and guidelines for the selection of aeration equipment and dissolved oxygen (DO) control systems for activated sludge treatment plants is summarized. Aeration methods, equipment, and application techniques are examined and selection procedures presented. Various DO control systems are described with recommendations for system applications to various aeration equipment types and process configurations. Automatic DO control systems are presented for various size hypothetical activated sludge plants. Finally, the economics of manual and automatic DO control systems are explored using data derived from a study of 12 operating activated sludge plants. The conclusion is drawn that the capital and operating cost of automatic DO control systems is justified for activated sludge plants larger than 1 mgd, provided equipment is selected and applied in accordance with the guidelines of the design manual and a power cost equal to or greater than the national average power rate is applicable.