Occurrence and Control of Filamentous Bulking in A/O-MBR Biological Nitrogen Removal Process

The possibility of filamentous sludge bulking in A/O-MBR biological nitrogen removal process for treatment of simulated wastewater was investigated.The results showed that in the A/O-MBR biological nitrogen removal process,both excessive nitrification and high impact load could cause filamentous sludge bulking.For the filamentous bulking caused by these two factors,the control of the filamentous bacteria could not be achieved by simply recovering operation parameters of the process.While improving the pH in the aeration tank to 9.0 or so and maintaining that level could inhibit and kill the filamentous bacteria.Besides,the filamentous sludge bulking would not recur in a short term.