Biological treatment processes require a stable microbial environment in the reaction system. This typically necessitates maintaining a high sludge concentration (MLSS) and an appropriate sludge retention time (SRT) to ensure sufficient degradation of organic matter and ammonia nitrogen. Simultaneously, the influent quality should be as balanced as possible to avoid excessive shock loads, which can negatively impact microbial activity and overall treatment efficiency.
Membrane operation processes require strict control of transmembrane pressure differential (TMP) and membrane flux. Constant flux or constant pressure operation is generally employed during operation, with real-time monitoring of TMP changes to assess membrane fouling. If pressure increases or flux decreases, timely backwashing or chemical cleaning is necessary to restore membrane performance and prevent irreversible fouling.
Membrane fouling control has specific requirements for aeration and hydraulic conditions. The aeration system must continuously provide sufficient shear force to reduce sludge deposition on the membrane surface; simultaneously, the hydraulic retention time (HRT) and return ratio need to be appropriately controlled to avoid excessive sludge accumulation or system load imbalance. Overall, the process requirements of Membrane bioreactor emphasize balanced system operation and refined control, which are key to achieving stable effluent and long-term operation.