Zeming An, Qiong Zhang, Xinjie Gao, Baishuo Shao, Yongzhen Peng
{"title":"优化 AAO 工艺,减少 N2O 排放并提高城市污水处理中的脱氮效果:探索碳补充和溶解氧控制策略","authors":"Zeming An, Qiong Zhang, Xinjie Gao, Baishuo Shao, Yongzhen Peng","doi":"10.1016/j.watres.2025.123247","DOIUrl":null,"url":null,"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 N<sub>2</sub>O emissions reduction is scarce. This study aimed to investigate the mitigation of N<sub>2</sub>O 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 N<sub>2</sub>O below 0.1 mgN/L. The moderate DO control (1-2 mg/L) could ensure the nitrification efficiency while reducing the gaseous N<sub>2</sub>O emission rate to 63.48 mgN/d, and decreasing the dissolved N<sub>2</sub>O concentration in the effluent to below 0.01 mgN/L. Both too high and too low DO levels were detrimental to N<sub>2</sub>O emission mitigation. The optimized AAO process achieved a significant reduction in the N<sub>2</sub>O emission factor to 0.85% and an increase in nitrogen removal efficiency to 81.81%. Additionally, the enrichment of anammox bacteria, <em>Candidatus brocadia</em> (0.15%), positively contributed to the improvement in nitrogen removal efficiency. In conclusion, this study provides valuable insights into optimizing AAO process to mitigate N<sub>2</sub>O emissions, enhance nitrogen removal, and lower carbon footprints associated with wastewater treatment.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"9 1","pages":""},"PeriodicalIF":11.4000,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Optimization of AAO process for reduced N2O emissions and enhanced nitrogen removal in municipal wastewater treatment: Exploring carbon supplementation and DO control strategies\",\"authors\":\"Zeming An, Qiong Zhang, Xinjie Gao, Baishuo Shao, Yongzhen Peng\",\"doi\":\"10.1016/j.watres.2025.123247\",\"DOIUrl\":null,\"url\":null,\"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 N<sub>2</sub>O emissions reduction is scarce. This study aimed to investigate the mitigation of N<sub>2</sub>O 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 N<sub>2</sub>O below 0.1 mgN/L. The moderate DO control (1-2 mg/L) could ensure the nitrification efficiency while reducing the gaseous N<sub>2</sub>O emission rate to 63.48 mgN/d, and decreasing the dissolved N<sub>2</sub>O concentration in the effluent to below 0.01 mgN/L. Both too high and too low DO levels were detrimental to N<sub>2</sub>O emission mitigation. The optimized AAO process achieved a significant reduction in the N<sub>2</sub>O emission factor to 0.85% and an increase in nitrogen removal efficiency to 81.81%. Additionally, the enrichment of anammox bacteria, <em>Candidatus brocadia</em> (0.15%), positively contributed to the improvement in nitrogen removal efficiency. In conclusion, this study provides valuable insights into optimizing AAO process to mitigate N<sub>2</sub>O emissions, enhance nitrogen removal, and lower carbon footprints associated with wastewater treatment.\",\"PeriodicalId\":443,\"journal\":{\"name\":\"Water Research\",\"volume\":\"9 1\",\"pages\":\"\"},\"PeriodicalIF\":11.4000,\"publicationDate\":\"2025-02-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Water Research\",\"FirstCategoryId\":\"93\",\"ListUrlMain\":\"https://doi.org/10.1016/j.watres.2025.123247\",\"RegionNum\":1,\"RegionCategory\":\"环境科学与生态学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENGINEERING, ENVIRONMENTAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Water Research","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1016/j.watres.2025.123247","RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
Optimization of AAO process for reduced N2O emissions and enhanced nitrogen removal in municipal wastewater treatment: Exploring carbon supplementation and DO control strategies
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.
期刊介绍:
Water Research, along with its open access companion journal Water Research X, serves as a platform for publishing original research papers covering various aspects of the science and technology related to the anthropogenic water cycle, water quality, and its management worldwide. The audience targeted by the journal comprises biologists, chemical engineers, chemists, civil engineers, environmental engineers, limnologists, and microbiologists. The scope of the journal include:
•Treatment processes for water and wastewaters (municipal, agricultural, industrial, and on-site treatment), including resource recovery and residuals management;
•Urban hydrology including sewer systems, stormwater management, and green infrastructure;
•Drinking water treatment and distribution;
•Potable and non-potable water reuse;
•Sanitation, public health, and risk assessment;
•Anaerobic digestion, solid and hazardous waste management, including source characterization and the effects and control of leachates and gaseous emissions;
•Contaminants (chemical, microbial, anthropogenic particles such as nanoparticles or microplastics) and related water quality sensing, monitoring, fate, and assessment;
•Anthropogenic impacts on inland, tidal, coastal and urban waters, focusing on surface and ground waters, and point and non-point sources of pollution;
•Environmental restoration, linked to surface water, groundwater and groundwater remediation;
•Analysis of the interfaces between sediments and water, and between water and atmosphere, focusing specifically on anthropogenic impacts;
•Mathematical modelling, systems analysis, machine learning, and beneficial use of big data related to the anthropogenic water cycle;
•Socio-economic, policy, and regulations studies.