College of Eco-Environmental Engineering, Guizhou Minzu University, Guiyang 550025, China.
Southwest Municipal Engineering Design & Research Institute of China, Chengdu 610213, China.
Bioresour Technol. 2024 Nov;412:131412. doi: 10.1016/j.biortech.2024.131412. Epub 2024 Sep 1.
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. H 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.
同步硝化反硝化（SND）是一种很有前途的脱氮工艺。然而，由于反硝化效果不理想，总氮（TN）去除受到限制。本研究表明，短时间（1 小时）预缺氧电刺激通过促进混合营养型和异养型反硝化菌的增殖，显著提高了好氧阶段的 SND 效率。在最佳电流（EC）（0.02 A）下，SND 和 TN 的去除效率分别达到 85.6%和 93.9%，比对照组分别提高了 39.1%和 17.2%。微生物群落分析表明，混合营养型和异养型反硝化菌的丰度显著增加。电刺激过程中产生的 H 诱导了混合营养型反硝化菌的增殖。弱 EC（0.02 A）通过加速电子转移促进了异养型反硝化菌的活性和生长，从而介导了异养反硝化作用，提高了 SND 效率。PICRUSt2 分析显示，脱氮基因的丰度显著增加。本研究为应用电解法在最小化能耗的同时实现先进的 SND 提供了新的思路。
