Study On Properties Of A~2/O Combined MBR Process And Control Of Membrane Fouling

The properties of two pilot-plant scales of MBR precess with A2/O combined MBR process on the treatment of domestic wastewater and control of membrane fouling were studied, Results showed that under the range of MLSS from 8.83g/L to 9.05g/L, the effect of removal of NH3-N was the best in MBR process;However, the NH3-N of effluent was lower than 1.35mg/L and the rate of removal of it reached 91.04% in A2/O combined MBR process;The rates of removal of CODcr,BOD5 and turbidity in the two process were all amont to 90%,the quality of effluent excelled the the standard of reuse water of country; The change of biofacies and properties of sludge was similar to conventional activated sludge process; Basic reason about performance difference of the three kind of membranes'mechanical strengths, the flux and the anti-pollution might be explained through SEM from the membrane silk microscopic structure; The effect of membrane submerged in alkaline solution and then in acid solution was better than that of other cleaning methods; The best technique to control fouling on-line was alkaline clean and then acid clean with dynamic bounce-back; The properties of MBR and effects of membrane fouling cleaning in pilot-plant scale were testified in industrial experiment, the two indicators of NH3-N and MLSS were applied in monitoring the state of start-up and long-term running of industrial MBR system,the sludge discharge periodically and cleaning on-line combined submerged cleaning in long-term running management were recommended.