Enhanced nitrogen removal by aerobic denitrifying bacteria via iron-anode pulsed electric field: performance,...

Recently, aerobic denitrification technology has gradually become a research hotspot in the biological nitrogen removal field. Nevertheless, challenges persist, including the facile loss of bacteria, suboptimal competitiveness, and the inability to establish favourable flora. Therefore, an iron anode pulsed electric field (PEF-Fe) is constructed to enhance aerobic denitrification process, through improving bacteria productivity to achieve biological denitrification strengthening. Through single-factor and response surface methodology (RSM) analysis, the cultivation conditions for Pseudomonas putida Wang207-14 (strain W207-14) were optimized. Furthermore, PEF-Fe was identified as the optimal enhancement system with an OD₆₀₀ of 1.74 within 8 h, and COD and nitrate nitrogen removal of approximately 99 % and 98 %. And molecular biological analysis further revealed PEF-Fe system modulated carbon and nitrogen metabolic pathways and electron transport process, promoting bacterial growth and inducing gene expression upregulation. This study provides a critical theoretical foundation and innovative direction for developing highly efficient microbial denitrification technologies.