A study on the evaluation method of MBR membrane replacement using permeability attenuation

All 3520 days’ operational data of an A2/O-MBR RWTP in Xi' an Siyuan University have been indiscriminately used to study an evaluation method of MBR hollow fibre membrane replacement. Two dimensionality reductions are carried out to obtain the annual industrial permeability, VMD2, from their daily values, as well as the annual trans-membrane pressure, TMP2, from the daily values. In the operation conditions, as membranes aging, three phenomena can be observed simultaneously. The permeate volume declined annually about 0.78 m3 per day per 1000 m2 membrane area per kPa TMP; The trans-membrane pressure increased annually about 0.66 kPa. The production capacity of the RWTP is annually decreased 47 m3 per day, decreased 2.41% from the original designed capacity. The frequency of cleaning events qualitatively increases. In a practical point of view, the membrane replacement interval is a technical and economic planned exercise, and affected by the MBR process design, the actual operating conditions, such as constant flux operation, different cleaning methods and procedures etc. Even though, data used in this paper have come out with limitation, but the methodology used still be meaningful.