Membrane bioreactors (MBR) represent an existing alternative to conventional wastewater treatment process. However, problems related to operation high costs, mainly due to membrane fouling, still needs to be addressed. The deposition of biomass and suspended solids on the membrane surfaces and within the membrane pore leads to an increase of the hydraulic resistance and permeate flux decline. Physical or chemical cleaning of the membrane is required to remove foulant and maintain optimum membrane performance in long term operation. Fouling can be limited, consequently reduced by using air scouring as commonly practised, by maintaining the permeate flux below critical flux. This flux is related to flux and trans-membrane pressure. Above critical flux fouling takes place and cleaning practise are necessary to restore membrane flux. This paper reports the trials that were conducted on a pilot scale WFM-IMBR for 30 days at subcritical flux operation using a real activated sludge.

Click below for the technical paper:
Technical Paper