Reactivation of hypersaline aerobic granular sludge after low-temperature storage

Reactivation of hypersaline aerobic granular sludge after low-temperature storage was studied by slowly increasing the organic loading. Results indicated that the basic external features of thawed hypersaline aerobic granules were still largely intact after a six-week low temperature storage, but the colors and internal structure changed greatly. Aerobic granules experienced a process of particle disintegration, fragmentary particles, filamentous bacteria-like particles, and dense granules during the recovery process. After more than one-month re-cultivation, the settling property, dehydrogenase activity, and nitrification properties of hypersaline aerobic granules returned to normal. During the re-cultivated process, the decentralized growth pattern of particles can be effectively controlled, and granules can grow compactly by controlling water alkalinity, aeration rate and reactor settling time.