Reactivation Characteristics of Stored Aerobic Nitrifying Granules
好氧硝化颗粒污泥搁置后活性恢复研究

A sequencing batch airlift reactor (SBAR) was conducted to study the performance of physical characteristics and respirometric activities during reactivation of aerobic granules after a 2-month storage time. Results showed that the color of the aerobic granules had completely become dark, the size and settleability did hardly change during the storage period. The color turned to be brownish-yellowish when the reactor was restarted for 2 weeks. The MLSS, granule size, and settleability increased rapidly along with reactivation. The heterotrophic activity resumed 86% within 1 day and was fully reactivated after 5 days. Then the COD removal rate was stabilized above 80%. Higher aeration rate and longer cycle time facilitated the reactivation of nitrifiers. When aeration rate was increased from 0.05 m3·h-1 to 0.10 m3·h-1 at 41th day, activities of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria were improved from 88% and 82% to 122% and 92%, respectively. The removal rate of ammonium-nitrogen promptly reached above 96%. Nitrite-oxidizing bacteria were fully reactivated after the cycle time was prolonged from 4 h to 6 h.