Membrane fouling is a big issue for membrane bioreactors, affecting their ability to treat wastewater effectively. To tackle this problem, researchers found that keeping the concentration of activated sludge and membrane flux below certain levels, and periodically discharging the activated sludge, can help optimize MBR operation. They also discovered that using a combination of gas and permeated effluent backwashing is more effective in removing cake layers on the membrane surface, reducing fouling, and restoring membrane flux. This technique is a successful way to prevent membrane fouling.