Related Experiment Video
Updated: Apr 13, 2026

Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction
Published on: April 10, 2018
Carbon dioxide and weak magnetic field enhance iron-carbon micro-electrolysis combined autotrophic denitrification
Wei Xing1, Guangxin Zhou2, Daoqing Gao3
1Beijing Key Laboratory of Aqueous Typical Pollutants Control and Water Quality Safeguard, School of Environment, Beijing Jiaotong University, Beijing 100044, PR China; Tangshan Research Institute of Beijing Jiaotong University, Hebei 063000, PR China.
Abstract:
Combining iron-carbon micro-electrolysis and autotrophic denitrification is promising for nitrate removal from wastewater. In this study, four continuous reactors were constructed using CO2 and weak magnetic field (WMF) to address challenges like iron passivation and pH stability. In the reactors with CO2 + WMF (10 and 35 mT), the increase in total nitrogen removal efficiency was significantly higher (96.2 ± 1.6 % and 94.1 ± 2.7 %, respectively) than that of the control (51.6 ± 2.7 %), and Fe3O4 converted to low-density FeO(OH) and FeCO3, preventing passivation film formation. The WMF application decreased the N2O emissions flux by 8.7 % and 20.5 %, respectively. With CO2 + WMF, the relative enzyme activity and abundance of denitrifying bacteria, especially unclassified_Rhodocyclaceae and Denitratisoma, increased. Thus, this study demonstrates that CO2 and WMF optimize the nitrate removal process, significantly enhancing removal efficiency, reducing greenhouse gas emissions, and improving process stability.
Related Concept Videos
Microbial Nutrition
Metabolism of Chemolithotrophs
Carbon-dioxide Fixation
Microbes and Methanogenesis
Microbes and Other Elemental Cycles
Microbial Corrosion

