Cao Xuekang, Chen Yinguang, Zheng Hao, Liao Yong, Feng Lihua, Feng Jiacheng, Liu Chao, Ji Fangying
State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Bioresour Technol. 2025 Aug;429:132504. doi: 10.1016/j.biortech.2025.132504. Epub 2025 Apr 8.
Constructed wetlands (CWs) are widely used for nitrogen pollution control in rural aquatic environments, yet their nitrogen removal efficiency often remains suboptimal. This study firstly examines how zeolite robustly stimulates Fe-utilization of steelmaking waste (i.e., steel slag) to improve nitrification and autotrophic denitrification of low carbon-to-nitrogen (C/N) ratio wastewater (C/N ≈ 1). Steel slag, by providing alkalinity for nitrification, also serves as an electron donor for denitrification due to its low-valent iron content. As a result, the total nitrogen (TN) removal efficiency was increased by 153.5% compared to the control group. Zeolite reshaped the microbial consortia, enriching iron autotrophic denitrifying bacteria and aerobic denitrifying bacteria. More importantly, zeolite facilitated microbial iron utilization by enhancing transmembrane iron transport and intracellular iron oxidation to boost nitrification and autotrophic denitrification without additional aeration, external carbon sources, or pH regulation. Our work advances understanding the development of low carbon technologies for wastewater nitrogen removal.
人工湿地（CWs）被广泛用于农村水环境中的氮污染控制，但其脱氮效率往往仍不理想。本研究首先考察了沸石如何有力地促进炼钢废料（即钢渣）的铁利用，以提高低碳氮比（C/N）废水（C/N≈1）的硝化作用和自养反硝化作用。钢渣通过为硝化作用提供碱度，因其低价铁含量也可作为反硝化作用的电子供体。结果，与对照组相比，总氮（TN）去除效率提高了153.5%。沸石重塑了微生物群落，富集了铁自养反硝化细菌和好氧反硝化细菌。更重要的是，沸石通过增强跨膜铁转运和细胞内铁氧化促进微生物铁利用，从而在无需额外曝气、外部碳源或pH调节的情况下提高硝化作用和自养反硝化作用。我们的工作推动了对低碳废水脱氮技术发展的理解。
