this thesis focused on effects of transient conditions (ph shocks, temperature variation and temperature shocks) on the performance and membrane fouling characterization and control of submerged anaerobic membrane bioreactors (sanmbr) for pulp and paper effluent treatment (thermomechanical whitewater and pressate). a comprehensive characterization of cake layer formed on membrane surfaces was conducted using various techniques. results show that a ph 8.0 shock had a minor impact, while ph 9.1 and 10.0 shocks exerted significant long-lasting negative impacts on performance of the sanmbr. the sanmbr system was highly resilient and could successfully tolerate the 5 °c/10 °c temperatures shocks at 37 °c and the temperature variations from 37 to 45 °c. the temperature shock of 5 °c and 10 °c at 45 °c led to slight disturbance and significant disturbance of the performance, respectively.