不同恢复方式对硝化颗粒污泥活性的影响

利用SBR反应器培养的成熟好氧硝化颗粒污泥,进行了硝化颗粒污泥临界活性以及不同氨氮浓度及曝气时间对储存的好氧硝化颗粒污泥活性恢复的影响研究.结果表明,储存不同时间的硝化菌活性(SOUR,O2/VSS)差别较大,储存前硝化颗粒污泥硝化菌SOUR为13.15 mg·(g·h)-1,储存20 d的硝化菌SOUR下降了1.26 mg·(g·h)-1,恢复运行了5个周期,氨氮去除率已经达到95%以上,恢复后活性为13.87 mg·(g·h)-1.但储存30 d的硝化菌SOUR降了11.63 mg·(g·h)-1,恢复运行51个周期后,氨氮去除率才达到92.64%,恢复后活性为14.92 mg·(g·h)-1,同时这种储存方法恢复时间较长,因此提出硝化颗粒污泥的临界活性为当硝化菌SOUR开始下降时,进行活性恢复.在临界活性的基础上,采用当硝化菌SOUR下降到临界活性时实施恢复,之后进入下一个储存周期,这种储存方式即为动态储存.当进水氨氮浓度分别为20、30、40 mg·L-1时,进行颗粒污泥活性恢复,进水氨氮浓度为40 mg·L-1恢复后硝化菌活性最高,经过3次动态储存后,其活性保持良好.当曝气时间分别为1、2、3 h时,进行颗粒污泥活性恢复,曝气时间为1 h时恢复后硝化菌活性最高,在动态储存过程中其活性一直保持较高水平.

Influence of Different Recovery Methods on the Activity of Nitrification Granular Sludge

Aerobic nitrifying granule sludge cultivated in sequential batch reactor (SBR) was used to investigate the critical activity point of granules and the effect of different ammonia concentration and aeration time on reactivation after storage. The results showed that there was big difference in the activity (SOUR, O₂/VSS) of nitrifying bacteria after different storage time. The specific oxygen utilization rate (SOUR) of granules before storage was 13.15 mg·(g·h)^-1. After a storage period of 20 days, the SOUR decreased by 1.26 mg·(g·h)^-1, after 5 cycles of reactivation, the ammonia removal efficiency was already increased to 95% while the SOUR was recovered to 13.87 mg·(g·h)^-1. But after a storage period of 30 days, the SOUR decreased by 11.63 mg·(g·h)^-1, after 51 cycles of reactivation, the ammonia removal efficiecny only reached 92.64% while the SOUR was recovered to 14.92 mg·(g·h)^-1. Meanwhile, this storage method required a longer recovery time. Therefore, we put forward that the critical activity of denitrifying granular sludge should be the activity when activity recovery starts and the nitrifying bacteria SOUR begins to decline. On the basis of the critical activity, we began to restore the activity when the activity of the denitrifying bacteria was reduced to critical activity, and then started a new storage cycle. This storage method was named dynamic storage. Different influent ammonia concentrations of 20, 30 and 40 mg·L^-1 were applied to reactivate the aerobic granules. Highest SOUR could be achieved when fed with an ammonia concentration of 40 mg·L^-1 after reactivation. After three times of dynamic storage, the SOUR remained stable. Different aeration time of 1, 2 and 3 h was applied to reactivate the aerobic granules. Highest SOUR could be obtained when aeration time of 1 h was applied after reactivation and remained stable along with dynamic storage.