2. Auxiliary agents: during the operation , it is often necessary to add some auxiliary agents, such as defoamer and coagulant. In this case, agents that do not damage the membrane structure and do not pollute the membrane surface should be selected, such as advanced ethanol series defoamers.
3. Non degradable substances: the raw water may contain fiber, hair and other substances, which are difficult to be removed by biochemical treatment or chemical coagulation. Therefore, when the raw water contains such substances, it should be pretreated with fine grid before entering the reactor.
4. MLSS concentration: if the activated sludge concentration is too high or too low, the membrane pressure difference will increase. It is suggested that the MLSS value should be 5000 ~ 12000mg / L, the limit use range should be 3000 ~ 15000mg / L, and the optimal range should be 5000 ~ 6000mg / L.
5. Sludge viscosity: when sludge viscosity is less than or equal to 30MPa · s, it is good for the operation of the system.
6. Temperature: MBR membrane products can be applied in the temperature range of 5 ~ 45 ℃, but considering the state of activated sludge, it is suggested that the operation effect is better in the range of 15 ~ 35 ℃.
