Stochastic modeling of an industrial activated sludge process

The purpose of this paper is to develop a Box-Jenkins time series transfer function model of the effluent COD using the influent COD, from a sewage treatment process. The data is from an industrial waste treatment plant encompassing a 14-month period.The work was done in 3 steps: (1) Box-Jenkins ARIMA (autoregressive integrated moving average) modeling of the influent COD; (2) ARIMA modeling of the effluent COD; and (3) development of a transfer function model for the waste treatment process.It was found that single difference models best described influent and effluent COD. For the transfer function model, the influent COD had an insignificant effect on the effluent COD.