Jose Jimenez , Kayla Bauhs , Mark Miller , Peter Dold , Ahmed Al-Omari , Manel Garrido , Dev Hiripitiyage , Megan Wittman , Gillian Burger , Kartik Chandran , Belinda Sturm
{"title":"通过动力学选择的低溶解氧硝化","authors":"Jose Jimenez , Kayla Bauhs , Mark Miller , Peter Dold , Ahmed Al-Omari , Manel Garrido , Dev Hiripitiyage , Megan Wittman , Gillian Burger , Kartik Chandran , Belinda Sturm","doi":"10.1016/j.watres.2025.124642","DOIUrl":null,"url":null,"abstract":"<div><div>Recent research in wastewater treatment demonstrates that activated sludge plants can be operated more efficiently in terms of energy and carbon utilization without the need for new infrastructure through the implementation of low dissolved oxygen (DO) operation. The aim of this study was to understand how microbial communities adapt to long-term low DO operations and the implications for nitrification. This study synthesized findings from bench-scale and full-scale experiments to assess the impact of low DO operation on nitrification rates, microbial community structure, and nitrous oxide (N<sub>2</sub>O) generation. Long-term exposure to low DO conditions led to a shift in the nitrifier community structure, favoring comammox bacteria (CMX) and, in some cases, ammonia-oxidizing archaea (AOA) over canonical ammonia-oxidizing and nitrite-oxidizing bacteria (AOB, NOB). In conventional high-DO systems, the ratio of nitrate production rate to ammonia removal rate is approximately 0.78, reflecting the lower growth rate of NOB compared to AOB. However, in the low DO facilities studied, this ratio approached 1.0, indicating that nearly all ammonia removed was directly converted to nitrate. This finding strongly supports the dominance of CMX which can perform complete ammonia oxidation in a single organism. The correlation between increased CMX abundance and increased nitrate production rates was consistent across facilities operating at different DO levels. These adapted communities demonstrated higher oxygen affinity compared to AOB and NOB from plants operated at high DO concentrations. Long-term exposure of biomass to low DO concentration may have resulted in a decrease in N<sub>2</sub>O emissions since there is a low relative abundance of AOB and NOB, limiting N<sub>2</sub>O production via the hydroxylamine oxidation pathway and nitrifier denitrification by AOB.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"288 ","pages":"Article 124642"},"PeriodicalIF":12.4000,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Low dissolved oxygen nitrification through kinetic selection\",\"authors\":\"Jose Jimenez , Kayla Bauhs , Mark Miller , Peter Dold , Ahmed Al-Omari , Manel Garrido , Dev Hiripitiyage , Megan Wittman , Gillian Burger , Kartik Chandran , Belinda Sturm\",\"doi\":\"10.1016/j.watres.2025.124642\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Recent research in wastewater treatment demonstrates that activated sludge plants can be operated more efficiently in terms of energy and carbon utilization without the need for new infrastructure through the implementation of low dissolved oxygen (DO) operation. The aim of this study was to understand how microbial communities adapt to long-term low DO operations and the implications for nitrification. This study synthesized findings from bench-scale and full-scale experiments to assess the impact of low DO operation on nitrification rates, microbial community structure, and nitrous oxide (N<sub>2</sub>O) generation. Long-term exposure to low DO conditions led to a shift in the nitrifier community structure, favoring comammox bacteria (CMX) and, in some cases, ammonia-oxidizing archaea (AOA) over canonical ammonia-oxidizing and nitrite-oxidizing bacteria (AOB, NOB). In conventional high-DO systems, the ratio of nitrate production rate to ammonia removal rate is approximately 0.78, reflecting the lower growth rate of NOB compared to AOB. However, in the low DO facilities studied, this ratio approached 1.0, indicating that nearly all ammonia removed was directly converted to nitrate. This finding strongly supports the dominance of CMX which can perform complete ammonia oxidation in a single organism. The correlation between increased CMX abundance and increased nitrate production rates was consistent across facilities operating at different DO levels. These adapted communities demonstrated higher oxygen affinity compared to AOB and NOB from plants operated at high DO concentrations. Long-term exposure of biomass to low DO concentration may have resulted in a decrease in N<sub>2</sub>O emissions since there is a low relative abundance of AOB and NOB, limiting N<sub>2</sub>O production via the hydroxylamine oxidation pathway and nitrifier denitrification by AOB.</div></div>\",\"PeriodicalId\":443,\"journal\":{\"name\":\"Water Research\",\"volume\":\"288 \",\"pages\":\"Article 124642\"},\"PeriodicalIF\":12.4000,\"publicationDate\":\"2025-09-20\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Water Research\",\"FirstCategoryId\":\"93\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0043135425015453\",\"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://www.sciencedirect.com/science/article/pii/S0043135425015453","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}
Low dissolved oxygen nitrification through kinetic selection
Recent research in wastewater treatment demonstrates that activated sludge plants can be operated more efficiently in terms of energy and carbon utilization without the need for new infrastructure through the implementation of low dissolved oxygen (DO) operation. The aim of this study was to understand how microbial communities adapt to long-term low DO operations and the implications for nitrification. This study synthesized findings from bench-scale and full-scale experiments to assess the impact of low DO operation on nitrification rates, microbial community structure, and nitrous oxide (N2O) generation. Long-term exposure to low DO conditions led to a shift in the nitrifier community structure, favoring comammox bacteria (CMX) and, in some cases, ammonia-oxidizing archaea (AOA) over canonical ammonia-oxidizing and nitrite-oxidizing bacteria (AOB, NOB). In conventional high-DO systems, the ratio of nitrate production rate to ammonia removal rate is approximately 0.78, reflecting the lower growth rate of NOB compared to AOB. However, in the low DO facilities studied, this ratio approached 1.0, indicating that nearly all ammonia removed was directly converted to nitrate. This finding strongly supports the dominance of CMX which can perform complete ammonia oxidation in a single organism. The correlation between increased CMX abundance and increased nitrate production rates was consistent across facilities operating at different DO levels. These adapted communities demonstrated higher oxygen affinity compared to AOB and NOB from plants operated at high DO concentrations. Long-term exposure of biomass to low DO concentration may have resulted in a decrease in N2O emissions since there is a low relative abundance of AOB and NOB, limiting N2O production via the hydroxylamine oxidation pathway and nitrifier denitrification by AOB.
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.