Effect of C/N ratio on the denitrifying enzymes activity and global warming potential

2025

Desalination and Water Treatment, Vol 322, Iss , Pp 101074- (2025)

The greenhouse gases generated in the wastewater treatment process based on heterotrophic denitrification technology have become a dilemma between water environment protection and carbon emission reduction. Therefore, balancing the removal of nitrate pollutants and greenhouse gas emissions has become a key issue in ''green denitrification''. Based on the insufficient research of previous studies on C/N and global warming potential (GWP) in denitrification systems, this study constructed a series of batch experiments with different initial C/N to analyze their impact on the denitrifying enzymes specific activity concentration and the GWP caused by GHGs emissions. This study indicates that when the initial C/N is below 6.82, it leads to a decrease in the nitrous oxide reductase specific activity concentration by 0.11∼12.45 %, but an increase in the nitric oxide reductase specific activity concentration by 5.96∼22.01 %. In addition, when the initial C/N was between 2.34 ∼ 6.82, the GWP caused by every complete reduction of 1 mg NO-3-N has a better cost-effectiveness, with 0.09 ∼ 0.13 mmol CO2-eq/mg NO-3-N. Overall, the results of the study provide a reference for balancing the nitrate removal and the GWP caused by GHGs emission in wastewater treatment.

article

English

Elsevier, 2025.

Nitrous oxide reductase, Nitric oxide reductase, Global warming potential, Greenhouse gas, Environmental technology. Sanitary engineering, TD1-1066, Ecology, QH540-549.5