Work

Heme Induces the Cooperation of Feammox and Anammox to Improve the Removal of Ammonia Nitrogen

Year: 2025

Type: article

Abstract: 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.

Source: Environmental Technology & Innovation

DOI: 10.1016/j.eti.2025.104194

Authors: Zhenxin Wang, Qilin Yu, Zhiqiang Zhao, Ruicheng Zhang, Hongbo Zhang, Yaobin Zhang

Institutions: Thermal Power Research Institute, Dalian University of Technology

Language: English

Topic: Wastewater Treatment and Nitrogen Removal

Subfield: Pollution

Field: Environmental Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,930

Funder: National Natural Science Foundation of China