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Dong G, Ma G, Zhi J, Yu D, Zhang J, Zhang Y, Li J, Zhao X, Xia H, Zhou Z, Liu J, Miao Y. Increasing biomass concentration facilitates simultaneous nitrogen removal and sludge reduction under low C/N conditions. BIORESOURCE TECHNOLOGY 2024; 413:131532. [PMID: 39332697 DOI: 10.1016/j.biortech.2024.131532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2024] [Revised: 09/22/2024] [Accepted: 09/23/2024] [Indexed: 09/29/2024]
Abstract
To overcome the issues of limited carbon source and high sludge production in partial denitrification/anammox (PD/A) process, the effects of mixed liquor suspended solids (MLSS) and carbon/nitrogen ratio (C/N) on PD/A were investigated through parallel experiments. Nitrogen removal efficiencies decreased significantly when C/N was reduced (1.5 → 0.75). When MLSS was doubled, the nitrogen removal efficiencies in the two parallel reactors increased from 75.3 %, 72.9 % to 86.9 %, 89.7 %, respectively, and sludge yields decreased obviously. Combining with in-situ test, it was speculated when MLSS increased, fermentation was enhanced, providing substrate for partial denitrification. Thauera, involved in partial denitrification, decreased obviously with reduced C/N, but increased from 9.93 % to 38.16 % when MLSS doubled, which could promote the PD/A process. Terrimonas and Ignavibacterium (fermentative bacteria) increased from 1.26 %, 5.22 % to 6.62 %, 6.30 %, respectively. These results proved that increasing MLSS under low C/N ratios promoted fermentation in PD/A system, facilitating efficient nitrogen removal and sludge reduction.
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Affiliation(s)
- Guoqing Dong
- College of Environmental Science and Engineering, Qingdao University, Qingdao, China
| | - Guocheng Ma
- College of Environmental Science and Engineering, Qingdao University, Qingdao, China
| | - Jiaru Zhi
- College of Environmental Science and Engineering, Qingdao University, Qingdao, China
| | - Deshuang Yu
- College of Environmental Science and Engineering, Qingdao University, Qingdao, China
| | - Jianhua Zhang
- College of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao, China
| | - Yu Zhang
- College of Environmental Science and Engineering, Qingdao University, Qingdao, China
| | - Jiawen Li
- College of Environmental Science and Engineering, Qingdao University, Qingdao, China
| | - Xinchao Zhao
- College of Environmental Science and Engineering, Qingdao University, Qingdao, China
| | - Haizheng Xia
- College of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao, China
| | - Zian Zhou
- College of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao, China
| | - Jianjun Liu
- College of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao, China
| | - Yuanyuan Miao
- College of Environmental Science and Engineering, Qingdao University, Qingdao, China; College of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao, China.
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Gao Z, Bi X, Zhao J, Ding X, Li Y, Shi J, Pan X, Bai M, Miao Y, Zhang J. Self-cultivating anammox granules for enhancing wastewater nitrogen removal in nitrification-denitrification flocculent sludge system. BIORESOURCE TECHNOLOGY 2024; 397:130458. [PMID: 38373506 DOI: 10.1016/j.biortech.2024.130458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 02/02/2024] [Accepted: 02/14/2024] [Indexed: 02/21/2024]
Abstract
The feasibility of self-cultivating anammox granules for enhancing wastewater nitrogen removal was investigated in a nitrification-denitrification flocculent sludge system. Desirable nitrogen removal efficiency of 84 ± 4 % was obtained for the influent carbon to nitrogen ratio of 1-1.3 (NH4+-N: 150-200 mg N/L) via alternate anaerobic/oxic/anoxic mode. Meanwhile, some red granular sludge was formed in the system. The abundance and activity of anaerobic ammonia oxidation bacteria (AnAOB) increased from 'not detected' in seed sludge to 0.57 % and 29.4 ± 0.7 mg N/(g mixed liquor volatile suspended solids·h) in granules, respectively, suggesting successful cultivation of anammox granules. Furthermore, some denitrifying bacteria with capability of partial denitrification were enriched, such as Candidatus Competibacter (2.45 %) and Thauera (5.75 %), which could cooperate with AnAOB, facilitating AnAOB enrichment. Anammox was dominant in nitrogen removal with the contribution to nitrogen removed above 68.8 ± 0.3 %. The strategy of self-cultivating anammox granules could promote the application of anammox.
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Affiliation(s)
- Zhongxiu Gao
- State and Local Joint Engineering Research Centre of Urban Wastewater Treatment and Reclamation, School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266520, PR China
| | - Xuejun Bi
- State and Local Joint Engineering Research Centre of Urban Wastewater Treatment and Reclamation, School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266520, PR China
| | - Jixiang Zhao
- State and Local Joint Engineering Research Centre of Urban Wastewater Treatment and Reclamation, School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266520, PR China
| | - Xiang Ding
- State and Local Joint Engineering Research Centre of Urban Wastewater Treatment and Reclamation, School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266520, PR China
| | - Yitong Li
- State and Local Joint Engineering Research Centre of Urban Wastewater Treatment and Reclamation, School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266520, PR China
| | - Junhui Shi
- State and Local Joint Engineering Research Centre of Urban Wastewater Treatment and Reclamation, School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266520, PR China
| | - Xinlei Pan
- State and Local Joint Engineering Research Centre of Urban Wastewater Treatment and Reclamation, School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266520, PR China
| | - Meng Bai
- State and Local Joint Engineering Research Centre of Urban Wastewater Treatment and Reclamation, School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266520, PR China
| | - Yuanyuan Miao
- State and Local Joint Engineering Research Centre of Urban Wastewater Treatment and Reclamation, School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266520, PR China
| | - Jianhua Zhang
- State and Local Joint Engineering Research Centre of Urban Wastewater Treatment and Reclamation, School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266520, PR China.
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