SONGXin-yu,LIDa-peng,LIUSong-qi.Nitrogen Removal Effect and Greenhouse Gas Emission in Fe-C Based Intermittent Aeration Constructed Wetlands[J].China Water & Wastewater,2025,41(21):10-16.
Nitrogen Removal Effect and Greenhouse Gas Emission in Fe-C Based Intermittent Aeration Constructed Wetlands
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第41卷
Number:
第21期
Page:
10-16
Column:
Date of publication:
2025-11-01
- Keywords:
- intermittent aeration constructed wetland; greenhouse gas; pyrite; biochar; deep nitrogen removal of tailwater
- Abstract:
- The removal efficiency of total nitrogen (TN) in traditional constructed wetlands (CWs) is limited by the insufficient availability of carbon sources in tailwater and low-temperature conditions, which is also accompanied by significant greenhouse gas (GHG) emissions, including N2O, CO2, and CH4. Biochar and pyrite were employed as substrates to investigate the nitrogen removal performance and GHG emissions of Fe-C based intermittent aeration CWs for treating tailwater with a low carbon-to-nitrogen (C/N) ratio. Additionally, the impact of temperature on the nitrogen removal efficiency of Fe-C based intermittent aeration CWs was evaluated. Results showed that the Fe-C based CW achieved 17.1% and 11.5% higher TN removal than conventional gravel CW at 10 ℃and 25 ℃, respectively, without contributing to additional GHG emissions. Temperature had no significant effect on ammonia nitrogen (NH4+-N) removal, but low temperatures hindered nitrate nitrogen (NO3--N) removal, leading to inefficient TN removal. The abundance of nitrification functional genes (amoA) and denitrification functional genes (nosZ) in the system remained unaffected by low temperatures. However, the decreased activities of ammonia monooxygenase (AMO) and nitrous oxide reductase (NOS) were identified as the key factors limiting TN removal performance.
Last Update:
2025-11-01