Modelling a novel batch biofilm passive aeration technology using Aquasim

The Pumped Flow Biofilm Reactor (PFBR) is a new biofilm-based passive aeration system (PAS) that is an example of a complex biofilm system. The PFBR is a two reactor technology that employs a unique hydraulic regime and enables aerobic, anoxic and anaerobic conditions to be sequenced. Biofilm, growing on plastic media modules within the two reactors, is aerated passively as wastewater is moved alternately between the reactors during an aeration sequence. Thus as the two reactors empty and fill a number of times during a typical aeration sequence, the biofilm is exposed, in turn, to atmospheric air and wastewater. Thus the system, while simple to design and operate, provides a particular challenge to modellers. Given its complexity, due to the passive aeration system achieved using a unique hydraulic flow regime; previous models have only been concerned with simulating the effluent from the PFBR. To date, models for the PFBR technology have not focused on the cycle performance of the PFBR, biofilm thickness or biofilm composition. It is proposed to model the PFBR using the modelling package AQUASIM in order to study the PFBR at a micro-scale level; this will enable the study of cycle performance, biofilm thickness and biofilm composition.