ABSTRACT

Anaerobic ammonia oxidation (anammox) process was achieved in a constructed rapid infiltration (CRI) system and the effect of organic matter on the anammox performance and microbial community structure was investigated. The results showed that the removal efficiencies of ${\mathrm{N}\mathrm{H}}_4^{+}$-N, ${\mathrm{N}\mathrm{O}}_2^{-}$N and TN were 99.7 ± 0.3%, 99.8 ± 0.2% and 91.3 ± 0.2% respectively after 83 days of acclimation without the presence of organic matter in the influent. The average TN removal efficiency increased by 3.2%–7.7% due to the synergistic effect of anammox and denitrification at a low level of organic matter concentration (10–30 mg COD/L). At medium or high organic matter concentration (50–100 mg COD/L), denitrification gradually replaced anammox as the predominant nitrogen removal route due to its stronger ability to compete with substrate, resulting in a significant decline in anammox activity. The contribution rate of anammox to nitrogen removal dropped by 70.3% with the influent COD increased from 0 to 100 mg/L, and the TN removal efficiency decreased to 68.4 ± 3.6% since the anammox was seriously suppressed. 16S rRNA high-throughput sequencing analysis illustrated that the genus Candidatus Kuenenia was the predominant anammox bacteria (AAOB) with a relative abundance of 12.63% when no organic matter was applied. While the heterotrophic denitrifying bacteria (DNB) Thauera gradually dominated the community with the elevated organic matter introduction. The findings of this study provide useful information for the stable operation and optimal regulation of anammox in the CRI system when the influent contains organic matter.

摘要

在构建的快速渗透（CRI）系统中实现了厌氧氨氧化（anammox）过程，并研究了有机物对厌氧氨氧化性能和微生物群落结构的影响。结果表明，去除效率${\mathrm{ñ}\mathrm{H}}_4^{+}$-N,${\mathrm{ñ}\mathrm{○}}_2^{-}$在进水不存在有机物的情况下，经过 83 天的驯化后，N 和 TN 分别为 99.7 ± 0.3%、99.8 ± 0.2% 和 91.3 ± 0.2%。由于厌氧氨氧化和反硝化在低有机物浓度（10-30 mg COD/L）下的协同作用，TN的平均去除效率提高了3.2%-7.7%。在中等或高有机物浓度（50-100 mg COD/L）下，由于反硝化与底物竞争的能力更强，反硝化逐渐取代厌氧氨氧化成为主要的脱氮途径，导致厌氧氨氧化活性显着下降。随着进水COD从0增加到100 mg/L，厌氧氨氧化对脱氮的贡献率下降了70.3%，由于厌氧氨氧化被严重抑制，TN去除效率下降到68.4±3.6%。Candidatus Kuenenia是主要的厌氧氨氧化细菌 (AAOB)，在不施用有机物时的相对丰度为 12.63%。而异养反硝化细菌（DNB）Thauera随着有机物引入量的增加逐渐主导群落。当进水含有有机物时，本研究的结果为 CRI 系统中厌氧氨氧化的稳定运行和优化调节提供了有用的信息。