Membrane bioreactor for chemical wastewater treatment without P

The running of membrane bioreactor (MBR) without P in the influent was studied. The results show that the microorganisms cought grow up by using polyphosphate in their bodies, or the phosphor released from the dead-bodies; At the initial stage, MLSS keeps on increasing, and remains at 8.5 g/L finally; During the experimental period, the chemical oxygen demand (COD) removal efficiency is always stable and excellent. The removals of the NH₄⁺-N and total nitrogen reach 90% and 70%, respectively after a period of running. Research on the property of MLSS indicates that filamentous bulking and non-filamentous bulking both occur in this system. According to the experimental results, it has no effect on the MBR system when there is no phosphor in the influent.