Enhanced nitrogen removal via SNAD-IFAS process treating THP-AD liquor: microbial community and co-metabolism mechanism

Abstract The anaerobic digester liquor after thermal hydrolysis pretreatment (THP-AD liquor) is a highly hazardous wastewater containing high concentration of ammonium. Herein, a novel two-stage tandem-type simultaneous partial nitrification, anammox, and denitrification-integrated fixed biofilm act...

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Main Authors: Xiaochen Xu, Xiao Feng, Weichun Gao, Fenglin Yang, Bing Liu, Chao Wang
Format: Article
Language:English
Published: Nature Portfolio 2025-08-01
Series:npj Clean Water
Online Access:https://doi.org/10.1038/s41545-025-00502-1
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author Xiaochen Xu
Xiao Feng
Weichun Gao
Fenglin Yang
Bing Liu
Chao Wang
author_facet Xiaochen Xu
Xiao Feng
Weichun Gao
Fenglin Yang
Bing Liu
Chao Wang
author_sort Xiaochen Xu
collection DOAJ
description Abstract The anaerobic digester liquor after thermal hydrolysis pretreatment (THP-AD liquor) is a highly hazardous wastewater containing high concentration of ammonium. Herein, a novel two-stage tandem-type simultaneous partial nitrification, anammox, and denitrification-integrated fixed biofilm activated sludge (SNAD-IFAS) hybrid process was successfully constructed for treating THP-AD liquor. The average removal efficiencies of ammonium, total nitrogen, and chemical oxygen demand in the stable phase were 94.0%, 89.9%, and 66.8%, respectively. The specific anammox activity of the two SNAD-IFAS reactors was 68.72 and 42.15 mg N/(g VSS·h), respectively. Candidatus Kuenenia and Candidatus Brocadia (13.49–20.94%) were the main genus of anammox bacteria. Although the relative abundance of Nitrosomonas (0.21–1.67%) was very lower than other bacteria, Nitrosomonas was a central genus in the co-occurrence network. Moreover, the genes involved in pyridine, dioxin, protein, and carbohydrate degradation were remarkably enriched in SNAD-IFAS, indicating the co-metabolism mechanism of refractory organic degradation. This study provides a low energy consumption, high efficiency, and low-carbon technology for treating THP-AD liquor.
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institution Kabale University
issn 2059-7037
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publishDate 2025-08-01
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series npj Clean Water
spelling doaj-art-333a1e1e9feb4c7cb4385efaf06954752025-08-20T03:42:34ZengNature Portfolionpj Clean Water2059-70372025-08-018111310.1038/s41545-025-00502-1Enhanced nitrogen removal via SNAD-IFAS process treating THP-AD liquor: microbial community and co-metabolism mechanismXiaochen Xu0Xiao Feng1Weichun Gao2Fenglin Yang3Bing Liu4Chao Wang5Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environment Science and Technology, Dalian University of TechnologyKey Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environment Science and Technology, Dalian University of TechnologySchool of Environmental and Chemical Engineering, Shenyang University of TechnologyKey Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environment Science and Technology, Dalian University of TechnologyCollege of Life and Environmental Science, Wenzhou UniversitySchool of Environmental and Chemical Engineering, Shenyang University of TechnologyAbstract The anaerobic digester liquor after thermal hydrolysis pretreatment (THP-AD liquor) is a highly hazardous wastewater containing high concentration of ammonium. Herein, a novel two-stage tandem-type simultaneous partial nitrification, anammox, and denitrification-integrated fixed biofilm activated sludge (SNAD-IFAS) hybrid process was successfully constructed for treating THP-AD liquor. The average removal efficiencies of ammonium, total nitrogen, and chemical oxygen demand in the stable phase were 94.0%, 89.9%, and 66.8%, respectively. The specific anammox activity of the two SNAD-IFAS reactors was 68.72 and 42.15 mg N/(g VSS·h), respectively. Candidatus Kuenenia and Candidatus Brocadia (13.49–20.94%) were the main genus of anammox bacteria. Although the relative abundance of Nitrosomonas (0.21–1.67%) was very lower than other bacteria, Nitrosomonas was a central genus in the co-occurrence network. Moreover, the genes involved in pyridine, dioxin, protein, and carbohydrate degradation were remarkably enriched in SNAD-IFAS, indicating the co-metabolism mechanism of refractory organic degradation. This study provides a low energy consumption, high efficiency, and low-carbon technology for treating THP-AD liquor.https://doi.org/10.1038/s41545-025-00502-1
spellingShingle Xiaochen Xu
Xiao Feng
Weichun Gao
Fenglin Yang
Bing Liu
Chao Wang
Enhanced nitrogen removal via SNAD-IFAS process treating THP-AD liquor: microbial community and co-metabolism mechanism
npj Clean Water
title Enhanced nitrogen removal via SNAD-IFAS process treating THP-AD liquor: microbial community and co-metabolism mechanism
title_full Enhanced nitrogen removal via SNAD-IFAS process treating THP-AD liquor: microbial community and co-metabolism mechanism
title_fullStr Enhanced nitrogen removal via SNAD-IFAS process treating THP-AD liquor: microbial community and co-metabolism mechanism
title_full_unstemmed Enhanced nitrogen removal via SNAD-IFAS process treating THP-AD liquor: microbial community and co-metabolism mechanism
title_short Enhanced nitrogen removal via SNAD-IFAS process treating THP-AD liquor: microbial community and co-metabolism mechanism
title_sort enhanced nitrogen removal via snad ifas process treating thp ad liquor microbial community and co metabolism mechanism
url https://doi.org/10.1038/s41545-025-00502-1
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