The present work focused on the rheological properties of activated sludge during the operation of a multi-habitat membrane reactor( MHMBR). The effects of mixed liquor suspended solids( MLSS) and shear rate on the rheological characteristics were investigated to reveal the rheological characteristics of activated sludge in the MHMBR and to provide a theoretical and experimental basis for optimizing the operation of this kind of MBR. The reactor was continuously operated for 105 days without discharging any...