The feasibility of the process described in Fig. 1 was examined for the accomplishment of adequate nitritation/denitritation as well as the recovery of PHA within the operation of a WWTP.
In order to promote the development of PHA storing biomass, feast and famine conditions were established. Municipal wastewater contained VFAs that could be used for PHA storage; however, this was not enough to reach complete denitritation, which require around 2.5 gCOD g1 N for denitritation. The carbon source added under aerobic conditions favoured the PHA storage.
The PHA was consumed in the subsequent famine phase for the removal of nitrite.
In the scSBR, during the feast conditions VFA were continuously depleted, while the famine phase was characterised by the complete absence of VFAs.