Time Series Models for Forecasting Wastewater Treatment Plant Performance

Abstract

This paper describes a time series modeling procedure that can be useful for calculating predictions, with confidence intervals, of effluent quality one to five days ahead, and it explains how these predictions can serve as an early warning of process upsets that will sometimes enable an operator to take preventive action. The time series model has the form of an exponentially weighted moving average (EWMA). The interpretation of the model is that the response of the system can be predicted by deviations from the EWMA smoothed values of the predictor variables.