Simultaneous nitrification–denitrification (SND) is a promising nitrogen removal process. However, total nitrogen (TN) removal is limited due to unsatisfactory denitrification. This study demonstrated that short-time (1 h) pre-anoxic electro-stimulation significantly enhanced SND efficiency in the aerobic phase by promoting the proliferation of mixotrophic and heterotrophic denitrifiers. SND and TN removal efficiencies at the optimal electric current (EC) (0.02 A) were 85.6 % and 93.9 %, which were 39.1 % and 17.2 % higher than control. Microbial community analysis indicated that the abundance of mixotrophic and heterotrophic denitrifiers significantly increased. H2 generated in the electro-stimulation process induced the proliferation of mixotrophic denitrifiers. The weak EC (0.02 A) promoted the activity and growth of heterotrophic denitrifiers by accelerating electron transfer. They concurrently mediated heterotrophic denitrification to enhance SND efficiency. PICRUSt2 analysis revealed that the abundance of denitrifying genes dramatically surged. This study provides new insights into applying electrolysis to achieve advanced SND while minimizing electricity consumption.

中文翻译：

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单级电解一体化序批式生物膜反应器预缺氧电刺激增强同步硝化反硝化


同步硝化反硝化（SND）是一种很有前景的脱氮工艺。然而，由于反硝化效果不理想，总氮（TN）的去除受到限制。这项研究表明，短时间（1 小时）预缺氧电刺激通过促进混合营养和异养反硝化菌的增殖，显着提高了有氧阶段的 SND 效率。在最佳电流（EC）（0.02 A）下，SND和TN去除效率分别为85.6%和93.9%，分别比对照高39.1%和17.2%。微生物群落分析表明，混合营养和异养反硝化菌的丰度显着增加。电刺激过程中产生的氢气诱导了混合营养反硝化菌的增殖。弱EC（0.02 A）通过加速电子转移促进异养反硝化菌的活性和生长。它们同时介导异养反硝化作用以提高 SND 效率。 PICRUSt2 分析显示反硝化基因的丰度急剧增加。这项研究为应用电解实现先进的 SND 同时最大限度地减少电力消耗提供了新的见解。