Physical Sciences and Mathematics Commons^™

Process Control Of Activated Sludge Treatment, Phase Ii, Richard I. Kermode, Robert W. J. Brett, Joseph D. Pault Jr.

KWRRI Research Reports

Material balances on substrate and microorganisms were derived in conjunction with various mixing configurations thought to accurately describe the activated sludge process. These models include the completely mixed with bypass, plug flow, and plug flow with bypass. Two sets of kinetic mechanisms for substrate utilization and bacterial growth were employed.

A feed forward controller was designed from linear approximations of the material balances derived in the completely mixed with bypass mixing model. Utilizing frequency response methods, the controller was found essentially identical to a completely mixed modeled controller developed in a prior investigation.

Through computer simulation the controller's effectiveness was …

Minimum Cost Design Of Water Distribution Systems, Don J. Wood, C. O. Charles

KWRRI Research Reports

The objective of this study was to develop the analytical tools and procedures for minimum cost design of water distribution systems. Both analog and digital means of carrying out pressure and flow calculations were developed. As a result of this effort, digital programs for pressure and flow calculations in water distribution systems were written and have been widely distributed to practicing engineers. One procedure is based on a direct solution of the basic system equations using a linearization scheme and has several advantages over conventional techniques such as the Hardy Cross method. These include avoiding the need to initially balance …

Process Control Of Activated Sludge Treatment, Richard I. Kermode, Robert W. J. Brett, Kenneth A. Debelak, John J. Davis

KWRRI Research Reports

General feed forward controllers, conforming to standard control modes, have been derived for an activated sludge process. The analysis indicated that the appropriate controllers are proportional control with measurement of substrate flow rate, and derivative control with measurement of inlet substrate concentration, and manipulation of the rate of return sludge by both controllers.

The performance of these controllers was tested by computer simulation of five dynamic aerator models with and without sludge storage, and with two settling basin models. In all cases significant reduction of the maximum exit substrate concentration was achieved. Additional improvement resulted from the use of sludge …