Modelling biofilm based technologies with activated sludge unit processes: A short cut to performance simulation? A short cut to performance simulation?

Biofilm-based passive aeration systems (PAS) have attracted recent attention as alternative, energy efficient and low maintenance technologies in the wastewater sector. However the modelling of biofilm-based PAS offers unique challenges for modellers, particularly where new technologies are not easily simulated using existing commercial modelling software. However, if the modeller is concerned only with simulating "macro" plant performance (e.g. key effluent concentrations and cycle analysis) it may be possible to efficiently model these technologies using "surrogate" unit process systems (e.g. using an activated sludge process to model a biofilm process). The pumped flow biofilm reactor (PFBR); a batch biofilm technology, is a recent example of a PAS. As a relatively new technology a predictive model for the PFBR system has yet to be developed. Indeed for novel passive aeration systems in general, it can be time consuming and difficult to develop new models that accurately describe performance. This research investigates the potential for (1) modelling the PFBR (an example of a batch biofilm PAS) using previously developed, simple activated sludge based models (2) predicting effluent results and contaminant concentration changes (nitrogen and organic carbon) during individual treatment cycles using the activated sludge object, and (3) using the calibrated model to predict the optimal operational regimes.