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An Z, Zhang Q, Gao X, Shao B, Peng Y. Optimization of AAO process for reduced N 2O emissions and enhanced nitrogen removal in municipal wastewater treatment: Exploring carbon supplementation and DO control strategies. WATER RESEARCH 2025; 276:123247. [PMID: 39919352 DOI: 10.1016/j.watres.2025.123247] [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: 10/30/2024] [Revised: 12/21/2024] [Accepted: 02/04/2025] [Indexed: 02/09/2025]
Abstract
The anaerobic/anoxic/oxic (AAO) process remains a common nutrient removal process in municipal wastewater treatment, yet research focusing on concurrent optimization of process performance and N2O emissions reduction is scarce. This study aimed to investigate the mitigation of N2O emissions and enhance nitrogen removal efficiency in an AAO system treating low C/N domestic wastewater by establishing a fully enclosed gas-collecting continuous flow reactor and implementing carbon supplementation and dissolved oxygen (DO) control strategies. The results indicated that carbon supplementation in the anoxic zone effectively reduced nitrate concentrations and mitigated the accumulation of dissolved N2O below 0.1 mgN/L. The moderate DO control (1-2 mg/L) could ensure the nitrification efficiency while reducing the gaseous N2O emission rate to 63.48 mgN/d, and decreasing the dissolved N2O concentration in the effluent to below 0.01 mgN/L. Both too high and too low DO levels were detrimental to N2O emission mitigation. The optimized AAO process achieved a significant reduction in the N2O emission factor to 0.85 % and an increase in nitrogen removal efficiency to 81.81 %. Additionally, the enrichment of anammox bacteria, Candidatus brocadia (0.15 %), positively contributed to the improvement in nitrogen removal efficiency. In conclusion, this study provides valuable insights into optimizing AAO process to mitigate N2O emissions, enhance nitrogen removal, and lower carbon footprints associated with wastewater treatment.
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Affiliation(s)
- Zeming An
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, PR China
| | - Qiong Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, PR China
| | - Xinjie Gao
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, PR China
| | - Baishuo Shao
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, PR China
| | - Yongzhen Peng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, PR China.
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Zhao Q, Peng Y, Li J, Jia T, Zhang Q, Zhang L. Pilot-scale implementation of mainstream anammox for municipal wastewater treatment against cold temperature. Nat Commun 2024; 15:10314. [PMID: 39609403 PMCID: PMC11604950 DOI: 10.1038/s41467-024-54805-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Accepted: 11/20/2024] [Indexed: 11/30/2024] Open
Abstract
Applying anammox to municipal wastewater treatment promises enormous energy and resource savings; however, seasonally cold conditions pose a considerable challenge, impeding its future applications towards non-tropical regions. In this study, we establish a pilot-scale wastewater treatment plant (50 m3/d) in northern China and implement the partial denitrification coupling anammox process on actual municipal wastewater. Despite seasonal cooling, the nitrogen removal efficiency remains high, ranging from 75.0 ± 4.6% at 27.8-20.0 °C to 70.4 ± 4.5% at 10-7.5 °C. This process exhibits remarkable low-temperature tolerance, achieving an in-situ anammox rate of 32.7 ± 4.7 g-N/(m3·d) at 10-7.5 °C and contributing up to 39.7 ± 6.7% to nitrogen removal. Further 15N stable isotope tracing and kinetic tests reveal that the partial denitrification is capable of supplying increasingly abundant NO2- to anammox with decreasing temperature, enabling robust mainstream anammox against seasonal cooling. From 27.8 °C to 7.5 °C, anammox bacteria not only survive but thrive under mainstream conditions, with absolute and relative abundances increasing by 429.1% and 343.5%, respectively. This pilot-scale study sheds fresh light on extending mainstream anammox towards non-tropical regions, taking a necessary step forward toward the sustainability goals of the wastewater treatment sector.
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Affiliation(s)
- Qi Zhao
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, China
| | - Yongzhen Peng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, China
| | - Jianwei Li
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, China
| | - Tipei Jia
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, China
| | - Qiong Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, China
| | - Liang Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, China.
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Wimalaweera IP, Wei Y, Zuo F, Tang Q, Ritigala T, Wang Y, Zhong H, Weerasooriya R, Jinadasa S, Weragoda S. Enhancing Rubber Industry Wastewater Treatment through an Integrated AnMBR and A/O MBR System: Performance, Membrane Fouling Analysis, and Microbial Community Evolution. MEMBRANES 2024; 14:130. [PMID: 38921497 PMCID: PMC11205297 DOI: 10.3390/membranes14060130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Revised: 05/28/2024] [Accepted: 05/28/2024] [Indexed: 06/27/2024]
Abstract
This study explores the effectiveness of an integrated anaerobic membrane bioreactor (AnMBR) coupled with an anoxic/oxic membrane bioreactor (A/O MBR) for the treatment of natural rubber industry wastewater with high sulfate, ammonia, and complex organic contents. This study was conducted at the lab-scale over a duration of 225 days to thoroughly investigate the efficiency and sustainability of the proposed treatment method. With a hydraulic retention time of 6 days for the total system, COD reductions were over 98%, which reduced the influent from 22,158 ± 2859 mg/L to 118 ± 74 mg/L of the effluent. The system demonstrates average NH3-N, TN, and total phosphorus (TP) removal efficiencies of 72.9 ± 5.7, 72.8 ± 5.6, and 71.3 ± 9.9, respectively. Despite an average whole biological system removal of 50.6%, the anaerobic reactor eliminated 44.9% of the raw WW sulfate. Analyses of membrane fouling revealed that organic fouling was more pronounced in the anaerobic membrane, whereas aerobic membrane fouling displayed varied profiles due to differential microbial and oxidative activities. Key bacterial genera, such as Desulfobacterota in the anaerobic stage and nitrifiers in the aerobic stage, are identified as instrumental in the biological processes. The microbial profile reveals a shift from methanogenesis to sulfide-driven autotrophic denitrification and sulfammox, with evidence of an active denitrification pathway in anaerobic/anoxic conditions. The system showcases its potential for industrial application, underpinning environmental sustainability through improved wastewater management.
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Affiliation(s)
- Ishanka Prabhath Wimalaweera
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (I.P.W.); (F.Z.); (Q.T.); (T.R.); (Y.W.); (H.Z.)
- Laboratory of Water Pollution Control Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- China-Sri Lanka Joint Research and Demonstration Center for Water Technology, Ministry of Water Supply, Meewathura, Kandy 20400, Sri Lanka;
| | - Yuansong Wei
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (I.P.W.); (F.Z.); (Q.T.); (T.R.); (Y.W.); (H.Z.)
- Laboratory of Water Pollution Control Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- China-Sri Lanka Joint Research and Demonstration Center for Water Technology, Ministry of Water Supply, Meewathura, Kandy 20400, Sri Lanka;
- National Institute of Fundamental Studies, Hanthana Road, Kandy 20000, Sri Lanka;
| | - Fumin Zuo
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (I.P.W.); (F.Z.); (Q.T.); (T.R.); (Y.W.); (H.Z.)
- Laboratory of Water Pollution Control Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qihe Tang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (I.P.W.); (F.Z.); (Q.T.); (T.R.); (Y.W.); (H.Z.)
- Laboratory of Water Pollution Control Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tharindu Ritigala
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (I.P.W.); (F.Z.); (Q.T.); (T.R.); (Y.W.); (H.Z.)
- Laboratory of Water Pollution Control Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yawei Wang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (I.P.W.); (F.Z.); (Q.T.); (T.R.); (Y.W.); (H.Z.)
- Laboratory of Water Pollution Control Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hui Zhong
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (I.P.W.); (F.Z.); (Q.T.); (T.R.); (Y.W.); (H.Z.)
- Laboratory of Water Pollution Control Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rohan Weerasooriya
- National Institute of Fundamental Studies, Hanthana Road, Kandy 20000, Sri Lanka;
| | - Shameen Jinadasa
- Department of Civil Engineering, University of Peradeniya, Kandy 20400, Sri Lanka;
- School of Engineering and Technology, Central Queensland University, Bundaberg, QLD 4670, Australia
| | - Sujithra Weragoda
- China-Sri Lanka Joint Research and Demonstration Center for Water Technology, Ministry of Water Supply, Meewathura, Kandy 20400, Sri Lanka;
- National Water Supply and Drainage Board, Kandy 20800, Sri Lanka
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Xie Y, Zhang Q, Wu Q, Zhang J, Dzakpasu M, Wang XC. Novel adaptive activated sludge process leverages flow fluctuations for simultaneous nitrification and denitrification in rural sewage treatment. WATER RESEARCH 2024; 255:121535. [PMID: 38564890 DOI: 10.1016/j.watres.2024.121535] [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: 01/28/2024] [Revised: 03/24/2024] [Accepted: 03/26/2024] [Indexed: 04/04/2024]
Abstract
The fluctuating characteristics of rural sewage flow pose a significant challenge for wastewater treatment plants, leading to poor effluent quality. This study establishes a novel adaptive activated sludge (AAS) process specifically designed to address this challenge. By dynamically adjusting to fluctuating water flow in situ, the AAS maintains system stability and promotes efficient pollutant removal. The core strategy of AAS leverages the inherent dissolved oxygen (DO) variations caused by flow fluctuations to establish an alternating anoxic-aerobic environment within the system. This alternating operation mode fosters the growth of aerobic denitrifiers, enabling the simultaneous nitrification and denitrification (SND) process. Over a 284-day operational period, the AAS achieved consistently high removal efficiencies, reaching 94 % for COD and 62.8 % for TN. Metagenomics sequencing revealed HN-AD bacteria as the dominant population, with the characteristic nap gene exhibiting a high relative abundance of 0.008 %, 0.010 %, 0.014 %, and 0.015 % in the anaerobic, anoxic, dynamic, and oxic zones, respectively. Overall, the AAS process demonstrates efficient pollutant removal and low-carbon treatment of rural sewage by transforming the disadvantage of flow fluctuation into an advantage for robust DO regulation. Thus, AAS offers a promising model for SND in rural sewage treatment.
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Affiliation(s)
- Yadong Xie
- Key Lab of Northwest Water Resource, Environment, and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an, 710055 China
| | - Qionghua Zhang
- Key Lab of Northwest Water Resource, Environment, and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an, 710055 China; International Science & Technology Cooperation Center for Urban Alternative Water Resources Development, Xi'an, 710055 China.
| | - Qi Wu
- Key Lab of Northwest Water Resource, Environment, and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an, 710055 China
| | - Jiyu Zhang
- Key Lab of Northwest Water Resource, Environment, and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an, 710055 China
| | - Mawuli Dzakpasu
- International Science & Technology Cooperation Center for Urban Alternative Water Resources Development, Xi'an, 710055 China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, China
| | - Xiaochang C Wang
- Key Lab of Northwest Water Resource, Environment, and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an, 710055 China; International Science & Technology Cooperation Center for Urban Alternative Water Resources Development, Xi'an, 710055 China
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