升流式生物膜反应器中CANON工艺处理中低浓度氨氮废水的快速启动

Fast start of CANON process to treat medium and low concentration ammonia nitrogen wastewater in upflow biofilm reactor

为了实现中低浓度氨氮废水情况下CANON工艺的快速启动和稳定运行,在升流式生物膜反应器中,通过调控水力停留时间、溶解氧和回流比,研究进水氨氮浓度为200 mg·L-1时CANON工艺的快速启动过程。结果表明:1~17 d,污泥处于驯化阶段,HRT为12 h,DO控制在0.1~0.2 mg·L-1,50%的回流比满足污泥上升流态;18~60 d,HRT逐步缩短至8 h,DO控制在0.3~0.5 mg·L-1,回流比增大至150%,AOB和ANAMMOX在该阶段成功富集,填料上初步形成生物膜;61 d时,HRT缩短至6 h,加大回流比至200%,溶解氧控制在0.3~1.0 mg·L-1,系统启动加速,此时,进水氨氮负荷增加至0.795 kg·(m3·d)-1;运行至第93天,氨氮和总氮平均去除率分别达到95%和82%,ANAMMOX完成挂膜,CANON工艺成功启动。高通量测序结果显示,在整个启动过程中,优势菌群AOB和ANAMMOX的丰度呈增长趋势,启动完成时,生物膜中AOB占比19.46%,ANAMMOX占比22.49%,分别属于Brocadiaceae和Nitrosmonadaceae。CANON系统集成絮体、颗粒和填料挂膜3种污泥形态为一体,实现了在中低浓度氨氮废水中的高效稳定运行。

In order to achieve the fast start-up and stable operation of the CANON process under the conditions of medium and low concentration ammonia nitrogen wastewater, the volumetric nitrogen load in the start-up phase was optimized by adjusting the hydraulic retention time, dissolved oxygen and reflux ratio in the up-flow biofilm reactor, and the rapid start-up of the CANON process was studied when the influent ammonia nitrogen concentration was 200 mg·L-1. The results showed that during 1~17 d, the sludge was at the domestication stage,HRT was 12 h, DO was controlled between 0.1 mg·L-1 and 0.2 mg·L-1, and 50% reflux ratio satisfied the upflow state of sludge. During 18~60 d, HRT was gradually shortened to 8 h, DO was controlled between 0.3 mg·L-1 and 0.5 mg·L-1, and the reflux ratio increased to 150%, AOB and ANAMMOX were successfully enriched at this stage, and biofilm was preliminarily formed on the filler. On the 61st day, HRT was shortened to 6 h, the reflux ratio increased to 200%, the dissolved oxygen was controlled between 0.3 mg·L-1 and 1.0 mg·L-1, and the system start-up accelerated. At the same time, the influent nitrogen load increased to 0.795 kg·(m3·d)-1. After running to the 93 d, the average removal rates of ammonia nitrogen and total nitrogen reached 95% and 82%,respectively. The membrane forming of ANAMMOX and the start-up of CANON process successfully completed. The results of high-throughput sequencing showed that the abundance of dominant bacteria AOB and ANAMMOX increased during the whole start-up process. After completion of start-up, AOB and ANAMMOX accounted for 19.46% and 22.49% in biofilm, respectively, and belonged to Brocadiaceae and Nitrosomonadaceae, respectively. The CANON system integrated three kinds of sludge forms, such as flocs,granules and packing membranes, achieved efficient and stable operation in treating medium and low concentration ammonia nitrogen wastewater.