Fouling of a hollow fibre submerged membrane during long-term filtration of activated sludge

Membrane fouling of a hollow fiber submerged membrane during long-term filtration of activated sludge was investigated. The membrane bioreactor treating municipal wastewater was capable of long and stable performance without chemical cleaning. Using laboratory pump, the flow rates of permeate and feed water were maintained and measured. Using pressure gauge, the corresponding transmembrane pressure (TMP) was measured. The fouling rate was influenced by a physiological state of the biomass. During the filtration of starving biomass in the condition of floc breakage, an increased fouling rate was observed. It was concluded that the altered physiological state influenced the cake resistance, which was higher than obtained in the filtration of normal sludge.