Real-Time Control of Activated Sludge Process

Abstract

A technique for real-time control of the activated sludge process using specific oxygen uptake rate (SCOUR) has been developed. Mathematical modeling and computer simulation techniques were used to develop multivariant control strategies using SCOUR and mean cell retention time as the controlled variables, and manipulating sludge recycle rate, sludge wasting rate, and wastewater feed point location. It is shown that SCOUR is a valid indicator of process efficiency and sludge activity for nonsteady state operation, and that multivariant control techniques using SCOUR are superior to techniques that use only food-to-mass ratio, or mean cell retention time. It is also shown that SCOUR can be used to detect shock loads of toxic and biodegradable materials. The value of forecasting flow rates for improving control is illustrated through the use of time-series models.