Abstract: In order to prevent membrane fouling and improve the elimination effect of phosphorus, polymeric aluminum and fly-ash were fed to membrane bioreactor to change the property of wastewater treatment; meanwhile active sludge was analyzed with X-ray diffraction and infrared spectrum methods, and hollow membrane was probed with SEM to investigate the mechanism of membrane fouling. The results show that the property of active sludge and bio-membrane structure were changed by adding polymeric aluminum, especially the removal rate of phosphorous could reach 85% and the membrane fouling was reduced effectively. Moreover no effect was observed when ash-fly was fed into the membrane bioreactor.

Key words: membrane bioreactor, polymeric aluminum, fly-ash, membrane fouling