The storage of dried aerobic granular sludges under ambient condition

This study was conducted to observe the possibility of long-term storage of aerobic granular sludge (AGS) for further purposes. The research was done by drying the AGS and then stored in zip-lock bags placed in the laboratory and storage room. The AGS stored for 1 day in the laboratory, 1 week, and 1 month in both locations. The AGS then reactivated after each storage period, ran for 1 day, then performed analysis. After that, the reactivated AGS was redried to store for the next storing experiment. The analysis indicates that granules become darker and smaller in every reactivation by the size could reduce up to 28% after several time of drying and reactivating which is vice versa to granules settling velocity where it could increase up to 25% after storage. The granules stored for 1 day has the slightest effect on removal performance. Storing granules in a fluctuating temperature condition is possible but should not exceed 1 week. Although the removal performance dropped, it has the possibility to recover after the aerobic granular sludge was running continuously for a period.