两级ANAMMOX串联快速启动后置反应器的性能及机理

外源添加酰基高丝氨酸内酯类信号分子(AHLs)可以提高厌氧氨氧化菌(AAOB)的活性，有助于厌氧氨氧化(ANAMMOX)的快速启动，然而，AHLs的获取会增加操作成本。基于此，本研究构建了两级ANAMMOX串联反应器，以充分利用一级反应器(R1)出水有效成分实现后置反应器(R2)的快速启动。以R1的出水为进水，并逐渐过渡到以R1出水上清液和合成废水为进水的策略运行R2；通过脱氮性能、污泥特性和微生物群落变化来验证该策略的可行性，并进行了相关的机理分析。结果表明，R2在第56天实现了快速启动，运行90 d后，在总氮容积负荷为0.6～0.7 kg·(m³·d)^-1时，总氮去除率达到93%以上，显著高于直接以合成污水启动的对照组(R3，61%)。这可归因于R1流失污泥为R2提供了稳定的生物量补充，并且其上清液包含的群体感应信号分子促进了R2中AAOB的活性提高。高通量测序结果表明，R1出水引入的有机物导致R2群落多样性升高，反硝化菌等异养菌相对丰度增加，ANAMMOX功能菌Candidatus Brocadia占比下降，然而，与R1相比，R2物质运输和代谢相关功能基因表达水平上调。以上结果说明，通过两级ANAMMOX串联实现后置反应器的快速启动是可行的。

Performance and mechanism analysis of two-stage ANAMMOX in series to realize fast start-up of post reactor

Exogenous addition of acylhigh serine lactones (AHLs) can improve the activity of anaerobic ammonia oxidation bacteria (AAOB), which is conducive to the rapid start-up of anaerobic ammonia oxidation (ANAMMOX). However, the acquisition of AHLs increases the operating cost. Based on this, a two-stage ANAMMOX series reactor was constructed in this study to make full use of the effluent active components of the primary reactor (R1) to realize the rapid start-up of the post-reactor (R2). In the experiment, R1 effluent was used as the influent, and gradually transferred to the R1 effluent clear liquid and synthetic wastewater as the influent. The feasibility of the strategy was verified by nitrogen removal performance, sludge characteristics and microbial community changes, and the relevant mechanism was analyzed. The results showed that R2 achieved rapid start-up on the 56th day, its total nitrogen volume load was 0.6-0.7 kg·(m3·d)-1 after operation for 90 days, and its total nitrogen removal efficiency could reach higher than 93%, which was significantly higher than that of the control group (R3, 61%) started with synthetic sewage directly. This was attributed to the fact that the sludge lost from R1 provided a stable biomass supplement for R2, and the quorum-sensing signal molecules contained in its supernatant promoted the activity of AAOB in R2. High-throughput sequencing results showed that the organic matter introduced into R1 effluent led to an increase in R2 community diversity and the proportion of heterotrophic bacteria such as denitrification, and a decrease in the proportion of ANAMMOX functional bacteria Candidatus Brocadia. However, compared with R1, the expression levels of transport and metabolity-related functional genes in R2 were up-regulated. These results indicate that it is feasible to realize the rapid start-up of the post-reactor through two-stage ANAMMOX series.