[Online aeration backwashing in the inverse direction of effluent applied in dynamic membrane bio-reactor].

Aeration in the inverse direction of effluent was applied as the measure of online backwashing to control membrane pollution in the dynamic membrane bio-reactor treating sewage wastewater. When the intensity of aeration was 5.6 m3/(m2 x h) and the aeration time was 5 min, it took 45 min for the dynamic membrane to recover filtration capacity. With the recovery of dynamic membrane filterability, effluent turbidity was below 5 NTU. The backwashing interval of the reactor could maintain about 15 h. SEM pictures showed that online aeration backwashing in the inverse direction of effluent could efficiently destroy part of dynamic membrane layer. After the dynamic membrane recovery, dynamic membrane could check more than 50% TOC of various molecule weights range > 3 x 10(4). Aeration in the inverse direction of effluent was an economical and effective means of online backwashing in the dynamic membrane bio-reactor.