Dynamic Modeling of Membrane-Aerated Biofilm Reactors

A dynamic membrane-aerated biofilm reactor (MABR) model has been developed, calibrated, and validated using long-term data from the literature that includes process startup and upset conditions. With the adjustment of only the boundary layer thickness, the model was able to predict the dynamic performance of a pilot-scale MABR for 220 days across a range of loading conditions and temperature. The work is significant because it enables engineers to confidently use the model for the design of MABR processes which are becoming attractive due to their potential to contribute to energy-neutral WRRFs. To demonstrate potential applications of the MABR model, the calibrated model was used to compare an MABR to an equivalent moving-bed biofilm reactor (MBBR) system and to assess the impact of the biofilm thickness. It was found that the MABR offers a similar level of nitrification as with an MBBR but with much lower aeration requirements (67% reduction in airflow). The MABR also offers the potential for improved denitrification as compared to an MBBR without the need for an internal recycle stream but that this is contingent on ensuring that the biofilm does not become too thick. The model will allow the analysis of optimization potentials and subsequently support the more wide-spread use of MABR technology in wastewater treatment and resource recovery.