STRANGE ATTRACTORS AND CHAOS IN WASTE-WATER FLOW

This study investigates the complexity of wastewater flow phenomena using state-of-the-art chaos analysis. Techniques used are power spectrum, cor relation exponent, and Lyapunov exponent analyses. These techniques are general and can be used for other dynamic systems. The analyses provide a qualitative description of the irregular behavior of wastewater flow. Flow time series of three Ohio wastewater treatment plants are investigated. Among other things, the results indicate the presence of underlying strange attractors, which qualify the investigated flows as chaotic. These findings indicate that the structure of wastewater flow data can be very complex and that accurate prediction using stochastic models may be invalid. The procedures employed in this study can be used to evaluate flow models normally used in process control studies.