Ferric iron reduction coupled with anaerobic ammonium oxidation(Feammox)is a novel ferric-dependent autotrophic process for biological nitrogen removal(BNR)that has attracted increasing attention due to its low organic carbon requirement.However,extracellular electron transfer limits the nitrogen transformation rate.In this study,activated carbon(AC)was used as an electron shuttle and added into an integrated autotrophic BNR system consisting of Feammox and anammox processes.The nitrogen removal performance,nitrogen transformation pathways and microbial communities were investigated during 194 days of operation.During the stable operational period(days 126-194),the total nitrogen(TN)removal efficiency reached 82.9％±6.8％with a nitrogen removal rate of 0.46±0.04 kg-TN/m3/d.The contributions of the Feammox,anammox and heterotrophic denitrifica-tion pathways to TN loss accounted for 7.5％,89.5％and 3.0％,respectively.Batch experiments showed that AC was more effective in accelerating the Feammox rate than the anammox rate.X-ray photoelectron spectroscopy(XPS)analyses showed the presence of ferric iron(Fe(Ⅲ))and ferrous iron(Fe(Ⅱ))in secondary minerals.X-ray diffraction(XRD)patterns indicated that secondary iron species were formed on the surface of iron-AC carrier(Fe/AC),and Fe(Ⅲ)was primarily reduced by ammonium in the Feammox process.The phyla Anaerolineaceae(0.542％)and Candidatus Magasanikbacteria(0.147％)might contribute to the Feammox process,and Candidatus Jettenia(2.10％)and Candidatus Brocadia(1.18％)were the dominative anammox phyla in the bioreactor.Overall,the addition of AC provided an effective way to enhance the autotrophic BNR process by integrating Feammox and anammox.

Yingbin Hu;Ning Li;Jin Jiang;Yanbin Xu;Xiaonan Luo;Jie Cao

Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education,Institute of Environmental and Ecological Engineering,Guangdong University of Technology,Guangzhou 510006,China;Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou 511458,China;School of Environmental Science and Engineering,Guangdong University of Technology,Guangzhou 510006,China

环境科学与工程前沿

[1]Yingbin Hu;Ning Li;Jin Jiang;Yanbin Xu;Xiaonan Luo;Jie Cao-.Simultaneous Feammox and anammox process facilitated by activated carbon as an electron shuttle for autotrophic biological nitrogen removal)[J].环境科学与工程前沿,2022(07):83-95

BNR,denitrifica,Magasanikbacteria

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