Dynamic fouling behaviors of submerged nonwoven bioreactor for filtration of activated sludge with different SRT

► Different operating conditions of SRT varied sludge condition and caused dissimilar fouling characteristics. ► The mechanism of pore blocking by particles or colloids with size analogous to nonwoven pore led to irreversible fouling. ► The significant increases of colloid resistance were related to the irreversible fouling. ► To select the proper pore size of nonwoven according to the sludge condition is an essential strategy to avoid fouling in the nonwoven bioreactor.