Time series models for forecasting wastewater treatment plant performance Original Research Article

This article describes a time series modeling procedure that can be useful for calculating predictions, with confidence intervals, of effluent quality 1–5 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 response of the system can be predicted by deviations from the EWMA smoothed values of the predictor variables.