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We have developed a new approach to enhance granulation by adding water absorbing polymer (WAP) particles into the inoculated digested sludge. In this study, the effect of adding WAP on formation of anaerobic granular sludge was evaluated in lab-scale UASB reactors using two typical synthetic wastewater, i.e. glucose or volatile fatty acid (VFA) mixture solution. In addition, side by side with the lab-scale experiment, a pilot-scale experiment using the VFA mixture was carried out to evaluate the availability of accelerated start-up by adding WAP. The development of granular sludge was significantly enhanced by adding WAP. Granules developed on glucose and VFAs had high methanogenic activities and good settleability. From results of lab-scale experiment, the recommended dosage of WAP was about 750 mg/l of reactor volume. The results, pilot-scale experiment, indicated the availability of accelerated start-up by adding WAP.

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A lab-scale experiment on the performance of highly concentrated activated sludge in high strength fermentation wastewater treatment with rotary disk type UF membrane was carried out. The experiment lasted 252 days and was operated under continuous and various intermittent aeration conditions. TOC and NH4-N removals were quite good and intermittent aeration operations increased T-N removal efficiency. It demonstrated that activated sludge had strong ability for organic shock loading. However, the ability of nitrifier was weak compared with that of heterotrophic bacteria for pH shock. The activity of sludge in the reactor assessed by INT-dehydrogenase activity was not affected significantly after the incursion of anoxic operation, and the smaller coccus-like or rod-type bacteria (1-2μm) performed quite well for organic carbon and nitrogen removals.