BIORESOURCE TECHNOLOGY
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2025
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IF 9
Dun Guo,Lei Yang,Hao-Qi Lu,Yu-Chao Wang,Hong-Yan Meng,Pan Liang,Shen Cui,Zhang-Wei He,Jun Lan,Yong-Xiang Ren
Optimizing electron shuttles and revealing their mediating mechanisms are crucial for enhancing the ammonium (NH 4 + -N) oxidation coupled with Fe (III) reduction. In this study, anthraquinone-2,6-disulfonate (AQDs), riboflavin (RF), and humic acid (HA) were optimized in batch tests. The optimal dosages of 6, 2, and 8 mg/L for AQDs, RF, and HA resulted in average maximum NH 4 + -N removal of 80.2 %, 88.5 %, and 99.2 %, with 91.4 %, 88.5 %, and 74.7 % of the removed NH 4 + -N converted to nitrate, respectively. In addition, an enhanced extracellular electron transfer was also observed, including an enlarged current, diversified REDOX pathway, and reduced resistance. Outperformed AQDs in nitrogen removal and microbial activity, HA and RF were selected for the subsequent 100-day long-term investigation. During this stage, excess influent Fe tended to be stored as insoluble coatings on the sludge surface, while RF and HA facilitated its use to compensate for the reduced influent Fe 3+ . Meanwhile, they led to an increase in iron-reducing ( Comamonas ) and NH 4 + -N oxidizing bacteria ( Nitropsira and Planctomycetes ), as well as improvements in electrochemical characteristics and microbial activity. Moreover, microbial N and Fe metabolic potential were efficiently enhanced. Consequently, NH 4 + -N and TN removal rates were obviously increased to approximately 90 % and 40 %, respectively. The addition of electron shuttles led to long-term improvements in extracellular mass transfer and microbial metabolism, which contributed more than bridging the extracellular electron transfer. These results deepened the understanding of the effect of electron shuttles on Feammox.
研究领域:
环境科学
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微生物学
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DOI
PubMed
高影响因子
Environmental Technology & Innovation
·
2025
·
IF 7.1
Zhenxin Wang,Qilin Yu,Zhiqiang Zhao,Ruicheng Zhang,Hongbo Zhang,Yaobin Zhang
Anammox is limited in practical application due to the need to control the influent ratio of NO 2 - to NH 4 + . Fe(III) (hydr)oxides have been confirmed to serve as electron acceptors and induce a so-called Feammox to anaerobically oxidize ammonia in Anammox systems via extracellular electron transfer, which however is also restrained by the low activity of Fe(III) (hydr)oxides. Heme, a Fe-containing compound with high redox activity, was introduced into the Anammox system to improve NH 4 + oxidation in this study. A removal rate of 46.32 mg N/(L·d) was achieved for nitrogen through the addition of heme, which was 43.85% higher than the maximum Feammox efficiency in documents (32.20 mg N/(L·d)). Continuous experiments showed that the added heme participated in the intracellular and extracellular electron transfer of Anammox. The contribution of Feammox to nitrogen removal was affected by the influent NO 2 - -N/NH 4 + -N ratio. Under a high NO 2 - -N/NH 4 + -N ratio (1.25:1), the contribution of Feammox to NH 4 + -N removal was 8.29%. This ratio increased to 31.49% under a low NO 2 - -N/NH 4 + -N ratio (0.80). Besides increasing the nitrogen removal efficiency, heme addition may significantly lower the nitrite requirement in this biological process, leading to improved adaptability in its application.
研究领域:
环境微生物学
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污水处理
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DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 27
·期 21
·25899-25907
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IF 2.914
Yao Zongbao,Yang Liu,Song Na,Wang Changhui,Jiang Helong
As a recently discovered process of nitrogen cycling, anaerobic ammonium oxidation coupled to ferric iron reduction (Feammox) has attracted more attentions. This study investigated the spatial variation of Feammox in the sediment of different zones of a shallow freshwater lake and the effect of organic matter derived from algae and macrophyte on Feammox process. The potential Feammox rates showed significant differences among sediments from algae-dominated area (ADA), transitional area in the center of the lake (TDA), and macrophyte-dominated area (MDA), and in a descending order, ADA, MDA, and TDA. The potential Feammox rate ranged from 0.14 to 0.34 mg N kg −1 day −1 in the freshwater lake sediment. The potential Feammox rates of the sediment with algae or macrophyte amendment were 12.29% and 15.31% higher than the control test without algae and macrophyte amendment. The addition of algae or macrophyte to the sediment from TDA could improve the amount of HCl-extractable total Fe, Fe(III) reduction rate, and the abundance of FeRB. These results demonstrated that organic matter is one of the key regulators of Feammox process.
研究领域:
环境微生物学
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水生生态学
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生物地球化学
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DOI
PubMed
高影响因子
Desalination and Water Treatment
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2024
·
IF 1
Zongbao Yao,Changhui Wang,Na Song,Chunliu Wang,Helong Jiang
Anoxic ferric iron-dependent ammonium oxidation (Feammox) is a novel biological nitrogen removal process that oxidizes ammonium to NO 2 – , NO 3 – or N 2 using ferric iron as the electron acceptor. In this study, the Feammox process was successfully developed in a biofilm reactor using sponge iron as a Fe source feeding ammonium-containing aerobic water. The results showed that NH 4 + was oxidized to NO 3 – by Feammox. During 300 d of operation, the bioreactor demonstrated an average NH 4 + oxidation efficiency and rate of 42.3% and 32.2 mg N L –1 d –1 , respectively. Sponge iron was oxidized to ferric by dissolved oxygen (DO) in the influent and provided ferric and anaerobic conditions for Feammox. Only a small proportion of the generated NO 3 – was reduced to N 2 by nitrate-dependent Fe(II) oxidation causing nitrogen removal in the Feammox biofilm reactor. A distinct inhibition of Feammox was observed when DO increase to 1.0 mg L –1 . Microbiological composition analysis of the Feammox biomass showed that the dominant iron-reducing bacteria were Geobacter spp., Fervidicella, and Geothrix, which may contribute to Feammox. This study provides information on the process development of Feammox.
研究领域:
环境工程
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微生物生态学
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废水处理
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生物地球化学
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DOI
高影响因子
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