容积交换率对SNAD污泥颗粒化与稳定运行的影响

为研究不同容积交换率对同步亚硝化-厌氧氨氧化与反硝化工艺(SNAD)污泥颗粒化及稳定运行的影响, 采用容积交换率分别为37.5%(R1) 和75%(R2) 的SBR进行对比实验.结果表明，R1仅用36 d就实现了颗粒化，比R2快1/3，且颗粒化过程中R1的污泥流失较小; R1总氮去除速率(RNR)、单位MLVSS好氧氨氧化活性(RAO)和厌氧氨氧化活性(RAN)分别为0.356 g·L-1·d-1，0.113 0和0.080 9 g·g-1·d-1; R2的RNR、RAO和RAN分别为0.248 g·L-1·d-1，0.093 6和0.070 5 g·g-1·d-1.由此表明：较小的容积交换率有利于减少絮体流失，从而加快SNAD污泥的颗粒化进程; 有利于提高AOB与AnAOB的活性以及抑制NOB活性，从而实现SNAD工艺稳定高效的去除效果.
In order to study the effect of different volumetric exchange rates (VER) on the granulation and stable operation of SNAD sludge, two lab-scale SBR reactors, with a 37.5% VER (R1) and 75% VER (R2), were comparably analyzed. Experimental results demonstrated that the granulation of R1 could be achieved in 36 days, was 12 days faster than R2. Meanwhile, a relatively lower sludge loss rate of R1 was obtained. The nitrogen removal rate (RNR), RAO and RAN in R1 were 0.356 g·L-1·d-1, 0.113 0 and 0.080 9 g·g-1·d-1, respectively; while that of R2 was 0.248 g·L-1·d-1, 0.093 6 and 0.070 5 g·g-1·d-1, respectively. This confirmed that a lower VER reduced the loss of floc sludge, and further declined the granulation period. Moreover, a lower VER not only enhanced the activity of ammonia-oxidizing and anaerobic ammonia-oxidizing bacteria, but also suppressed nitrite-oxidizing bacteria, was benefit for a stable and efficient removal performance of the SNAD granular sludge.