[Characteristics of operational performance and membrane fouling in a sidestream membrane sequencing batch reactor with aerobic granule].
The characteristics of operational performance and membrane fouling were investigated using synthetic wastewater as feed in a sidestream membrane sequencing batch reactor (MSBR) system. The experimental results showed that the average removal efficiencies of COD, TN, TP and NH4+ -N were 90%, 60%-80%, 80% and 95% respectively under the influent COD of 200 mg x L(-1) to 1200 mg x L(-1) during more than 150 days' operation. It was possible to achieve a complete granulation of sludge. In 70th day, sludge particles around 350 microm were detected more than 90%. From then, sludge grew up continuously and finally reached to 394 microm in diameter. With the formation of granular sludge in MSBR, the cleaning time of membrane system was prolonged to 65 days, which was larger than three times compared with flocculent sludge MSBR. It was also much better than conventional MBR. These results clearly demonstrated that the formation of granular sludge was good for improving the resistance to organic loading shock and retaining the membrane fouling of the system, and maintaining the stable operation for a long time.