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Wang Y, Gao W, Lv L, Ma X, Ren Z, Sun L, Liu X, Wang P, Sun Z, Tian Y, Zhang G. Comprehensive carbon footprint analysis of wastewater treatment: A case study of modified cyclic activated sludge technology for low carbon source urban wastewater treatment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 923:171550. [PMID: 38461981 DOI: 10.1016/j.scitotenv.2024.171550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 01/30/2024] [Accepted: 03/04/2024] [Indexed: 03/12/2024]
Abstract
To reduce pollution and carbon emissions, a quantitative evaluation of the carbon footprint of the wastewater treatment processes is crucial. However, micro carbon element flow analysis is rarely focused considering treatment efficiency of different technology. In this research, a comprehensive carbon footprint analysis is established under the micro carbon element flow analysis and macro carbon footprint analysis based on life cycle assessment (LCA). Three wastewater treatment processes (i.e., anaerobic anoxic oxic, A2O; cyclic activated sludge technology, CAST; modified cyclic activated sludge technology, M-CAST) for low carbon source urban wastewater are selected. The micro key element flow analysis illustrated that carbon source mainly flows to the assimilation function to promote microorganism growth. The carbon footprint analysis illustrated that M-CAST as the optimal wastewater treatment process had the lowest global warming potential (GWP). The key to reduce carbon emissions is to limit electricity consumption in wastewater treatment processes. Under the comprehensive carbon footprint analysis, M-CAST has the lowest environmental impact with low carbon emissions. The sensitivity analysis results revealed that biotreatment section variables considerably reduced the environmental impact on the LCA and the GWP, followed by the sludge disposal section. With this research, the optimization scheme can guide wastewater treatment plants to optimize relevant treatment sections and reduce pollution and carbon emissions.
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Affiliation(s)
- Yuting Wang
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China
| | - Wenfang Gao
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China.
| | - Longyi Lv
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China.
| | - Xiaotian Ma
- Institute of Blue and Green Development, Weihai Institute of Interdisciplinary Research, Shandong University, Weihai 264209, China
| | - Zhijun Ren
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China
| | - Li Sun
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China
| | - Xiaoyang Liu
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China
| | - Pengfei Wang
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China
| | - Zhi Sun
- National Key Laboratory of Biochemical Engineering, Beijing Engineering Research Centre of Process Pollution Control, Institute of Process Engineering, Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing 100190, China
| | - Yu Tian
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Guangming Zhang
- Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
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Ranieri E, D'Onghia G, Lopopolo L, Gikas P, Ranieri F, Gika E, Spagnolo V, Ranieri AC. Evaluation of greenhouse gas emissions from aerobic and anaerobic wastewater treatment plants in Southeast of Italy. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 337:117767. [PMID: 36965371 DOI: 10.1016/j.jenvman.2023.117767] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/14/2023] [Accepted: 03/18/2023] [Indexed: 06/18/2023]
Abstract
An evaluation of the operative functioning data of 183 Wastewater Treatment Plants (WWTPs) in Apulia (Southeast of Italy) has been carried out aimed to assess their Green House Gases (GHGs) emissions and the level for which the use of anaerobic sludge treatment should be more convenient in terms of electricity consumption and of GHGs emissions. Out of the 183 studies WWTPs, 140 are practicing aerobic digestion of sludge, while the remaining 43 are practicing anaerobic digestion of sludge. WWTPs in Apulia are serving about 4,81 million PE (Population Equivalent), yielding approximately 600,000-ton equivalent CO2 per annum. The production of GHGs emissions has been estimated by evaluating the contribution of CO2 deriving from: a) electric energy consumption (fossil CO2), b) biogenic CO2, c) N2O and d) CH4 emissions. The present study investigates a number of technical measures for upgrading the existing WWTPs, so to reduce GHGs emissions through the amelioration of CH4 production and capture in the anaerobic step, and through reducing the production of biogenic N2O and CO2 emissions in the aerated basin. The methodology employees artificial intelligence-based control for upgrading the aerobic oxidation of the organic carbon and the nitrification-denitrification steps. As a result, GHGs emissions are expected to be reduced by approximately: 71% for CH4, 57% for N2O, 20% for biogenic CO2 and 15% for fossil derived CO2.
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Affiliation(s)
- Ezio Ranieri
- Universita Degli Studi di Bari, Dipartimento di Biologia, Bari, Italy.
| | | | - Luigi Lopopolo
- Universita Degli Studi di Bari, Dipartimento di Biologia, Bari, Italy.
| | - Petros Gikas
- Technical University of Crete, School of Chemical and Environmental Engineering, Chania, Greece.
| | - Francesca Ranieri
- Universita Degli Studi di Foggia, Dipartimento di Dipartimento di Economia, Management e Territorio, Foggia, Italy.
| | - Eleni Gika
- Technical University of Crete, School of Chemical and Environmental Engineering, Chania, Greece.
| | - Vincenzo Spagnolo
- Politecnico di Bari, Dipartimento Interateneo di Fisica, Bari, Italy.
| | - Ada Cristina Ranieri
- Politecnico di Bari, Dipartimento Interateneo di Fisica, Bari, Italy; Universita Internazionale Telematica Uninettuno, Roma, Italy.
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Huang L, Xiong H, Jiang C, He J, Lyu W, Chen Y. Pathways and biological mechanisms of N 2O emission reduction by adding biochar in the constructed wetland based on 15N stable isotope tracing. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 342:118359. [PMID: 37311348 DOI: 10.1016/j.jenvman.2023.118359] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 05/31/2023] [Accepted: 06/07/2023] [Indexed: 06/15/2023]
Abstract
Constructed wetlands (CWs) added with biochar were built to study pollutant removal efficiencies, nitrous oxide (N2O) emission characteristics, and biological mechanisms in nitrogen transformation. The results showed that biochar addition enhanced the average removal rates of ammonium (NH4+-N), total nitrogen, and chemical oxygen demand by 4.03-18.5%, 2.90-4.99%, and 2.87-5.20% respectively while reducing N2O emissions by 25.85-83.41%. Based on 15N stable isotope tracing, it was found that nitrification, denitrification, and simultaneous nitrification and denitrification were the main processes contributing to N2O emission. The addition of biochar resulted in maximum reduction rates of 71.50%, 80.66%, and 73.09% for these three processes, respectively. The relative abundance of nitrogen-transforming microbes, such as Nitrospira, Dechloromonas, and Denitratisoma, increased after the addition of biochar, promoting nitrogen removal and reducing N2O emissions. Adding biochar could increase the functional gene copy number and enzyme activity responsible for nitrogen conversion, which helped achieve efficient NH4+-N oxidation and eliminate nitrite accumulation, thereby reducing N2O emissions.
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Affiliation(s)
- Lei Huang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, 400715, PR China; Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, PR China; Chongqing Engineering Research Center of Rural Cleaner Production, Chongqing, 400716, PR China.
| | - Haifeng Xiong
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, 400715, PR China; Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, PR China
| | - Chunli Jiang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, 400715, PR China; Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, PR China
| | - Jinke He
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, 400715, PR China; Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, PR China
| | - Wanlin Lyu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, 400715, PR China; Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, PR China
| | - Yucheng Chen
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, 400715, PR China; Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, PR China; Chongqing Engineering Research Center of Rural Cleaner Production, Chongqing, 400716, PR China
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Hong Y, Tu Q, Cheng H, Huangfu X, Chen Z, He Q. Chronic high-dose silver nanoparticle exposure stimulates N 2O emissions by constructing anaerobic micro-environment. WATER RESEARCH 2022; 225:119104. [PMID: 36155009 DOI: 10.1016/j.watres.2022.119104] [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: 05/20/2022] [Revised: 09/05/2022] [Accepted: 09/10/2022] [Indexed: 06/16/2023]
Abstract
Silver nanoparticles (Ag-NPs) were found to be responsible for nitrous oxide (N2O) generation; however, the mechanism of Ag-NP induced N2O production remains controversial and needs to be elucidated. In this study, chronic Ag-NP exposure experiments were conducted in five independent sequencing batch biofilm reactors to systematically assess the effects of Ag-NPs on N2O emission. The results indicated that a low dose of Ag-NPs (< 1 mg/L) slightly suppressed N2O generation by less than 22.99% compared with the no-Ag-NP control method. In contrast, a high dose (5 mg/L) of Ag-NPs stimulated N2O emission by 67.54%. ICP-MS and SEM-EDS together revealed that high Ag-NP content accumulated on the biofilm surface when exposed to 5 mg/L Ag-NPs. N2O and DO microelectrodes, as well as N2O isotopic composition analyses, further demonstrated that the accumulated Ag-NPs construct the anaerobic zone in the biofilm, which is the primary factor for the stimulation of the nitrite reduction pathway to release N2O. A metagenomic analysis further attributed the higher N2O emissions under exposure to a high dose of Ag-NPs to the higher relative abundance of narB and nirK genes (i.e. 1.52- and 1.29-fold higher, respectively). These findings collectively suggest that chronic exposure to high doses of Ag-NPs could enhance N2O emissions by forming anaerobic micro-environments in biofilms.
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Affiliation(s)
- Yiyihui Hong
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Qianqian Tu
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China; China TieGong Investment & Construction Group Co., Ltd, Beijing 101300, China
| | - Hong Cheng
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China.
| | - Xiaoliu Huangfu
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Ziwei Chen
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Qiang He
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
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5
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Zhang S, Liu F, Xiao R, Lian S, Lv S. Effects of water level on nitrous oxide emissions from vegetated ditches. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 811:151419. [PMID: 34742973 DOI: 10.1016/j.scitotenv.2021.151419] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 10/29/2021] [Accepted: 10/30/2021] [Indexed: 06/13/2023]
Abstract
Nitrous oxide (N2O) is considered a powerful greenhouse gas. Vegetated ditches are an important source of N2O emissions in the agricultural systems. However, few studies have examined on the relationship between N2O emissions and the water level in vegetated ditches. To investigate the effect of water level on the N2O emissions, three pilot-scale ditches vegetated with Myriophyllum aquaticum were constructed with low (LW), medium (MW), and high (HW) water levels. The examined results indicated that the M. aquaticum ditches decreased N2O emissions by 38.4% and 67.9% in MW and HW, respectively, as compared to the LW ditch. In addition, the N2O emission factor decreased with increasing water level in the order of: LW (0.18%) > MW (0.11%) > HW (0.06%). The MW and HW ditches reduced the N2O emissions by controlling the sediment nitrogen contents, in which the ammonia nitrogen increased with increasing the level of water, while nitrate nitrogen decreased with increasing the level of water. The increase in the level of water significantly reduced the gene abundance of ammonia-oxidizing archaea (AOA) (p < 0.05), thereby reducing the N2O emissions in the MW and HW conditions due to the positive correlation between N2O emissions and AOA gene abundances. The unclassified_k_norank_d_Bacteria was the dominant denitrifying bacterial genus observed in the M. aquaticum ditches, and its highly relative abundance yielded low N2O emissions in the HW ditch. These findings indicate that reducing N2O emissions may be achieved by controlling the water level in vegetated ditches.
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Affiliation(s)
- Shunan Zhang
- Key Laboratory of Agro-ecological Processes in Subtropical Regions, Changsha Research Station for Agricultural & Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan 410125, China
| | - Feng Liu
- Key Laboratory of Agro-ecological Processes in Subtropical Regions, Changsha Research Station for Agricultural & Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan 410125, China; University of Chinese Academy of Sciences, Beijing 100039, China.
| | - Runlin Xiao
- Key Laboratory of Agro-ecological Processes in Subtropical Regions, Changsha Research Station for Agricultural & Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan 410125, China
| | - Shenhai Lian
- Key Laboratory of Agro-ecological Processes in Subtropical Regions, Changsha Research Station for Agricultural & Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan 410125, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Shuangtong Lv
- Key Laboratory of Agro-ecological Processes in Subtropical Regions, Changsha Research Station for Agricultural & Environmental Monitoring, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Hunan 410125, China; University of Chinese Academy of Sciences, Beijing 100039, China
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6
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Boiocchi R, Bertanza G. Evaluating the potential impact of energy-efficient ammonia control on the carbon footprint of a full-scale wastewater treatment plant. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2022; 85:1673-1687. [PMID: 35290239 DOI: 10.2166/wst.2022.052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
An assessment was performed for elucidating the possible impact of different aeration strategies on the carbon footprint of a full-scale wastewater treatment plant. Using a calibrated model, the impact of different aeration strategies was simulated. The ammonia controller tested showed its ability in ensuring effluent ammonia concentrations compliant with regulation along with significant savings on aeration energy, compared to fixed oxygen set point (DOsp) control strategies. At the same time, nitrous oxide emissions increased due to accumulation of nitrification intermediates. Nevertheless, when coupled with the carbon dioxide emissions due to electrical energy consumption for aeration, the overall carbon footprint was only marginally affected. Using the local average CO2 emission factor, ammonia control slightly reduced the carbon footprint with respect to the scenario where DOsp was fixed at 2 mg·L-1. Conversely, no significant change could be detected when compared against the scenarios where the DOsp was fixed. Overall, the actual impact of ammonia control on the carbon footprint compared to other aeration strategies was found to be strictly connected to the sources of energy employed, where the larger amount of low CO2-emitting energy is, the higher the relative increase in the carbon footprint will be.
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Affiliation(s)
- Riccardo Boiocchi
- DICATAM - Department of Civil, Environmental, Architectural Engineering and Mathematics, Universita degli Studi di Brescia, via Branze 43, 25123, Brescia, Italy E-mail:
| | - Giorgio Bertanza
- DICATAM - Department of Civil, Environmental, Architectural Engineering and Mathematics, Universita degli Studi di Brescia, via Branze 43, 25123, Brescia, Italy E-mail:
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Xi J, Gong H, Zhang Y, Dai X, Chen L. The evaluation of GHG emissions from Shanghai municipal wastewater treatment plants based on IPCC and operational data integrated methods (ODIM). THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 797:148967. [PMID: 34298368 DOI: 10.1016/j.scitotenv.2021.148967] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 06/23/2021] [Accepted: 07/06/2021] [Indexed: 06/13/2023]
Abstract
Due to the rapid wastewater treatment plants (WWTPs) development and the China's 2060 goal of carbon neutrality, the contribution of greenhouse gas (GHG) emissions from WWTPs should not be overlooked. Thus, the GHG accounting method, featured with site-specific and real operation data targeting city-level WWTPs, is scientifically and pragmatically called for. In this paper, we compared IPCC (IPCC 2006 and IPCC 2019), optimized IPCC and operational data integrated methods (ODIM) for the direct N2O and CH4 emissions for total 50 WWTPs in Shanghai. Data for all WWTPs were collected for ODIM and indirect GHG emissions evaluation, covering frequently used wastewater treatment processes in China such as anaerobic anoxic oxic, oxidation ditch, sequencing batch reactor, anoxic oxic, biofilm and membrane bio-reactor. The factors affecting the total GHG emissions intensity were also analyzed. The results showed that, in comparison with IPCC 2019, IPCC 2006 underestimated both direct N2O and CH4 emissions for a total percentage of 87%. What's more, IPCC 2019 overestimated by a percentage of 355% compared to ODIM due to the general default values. ODIM considered the significant differences in emission factor values of specific treatment process, making use of the local operational data to achieve more accurate city-level estimation with direct GHG emissions of 243,320 tCO2-eq in 2016. While indirect emissions were 511,851 tCO2-eq, accounting for 68% of total direct and indirect emissions. Average GHGs emission intensity for Shanghai WWTPs was evaluated as 0.290 kgCO2-eq/m3 while the specific WWTP intensity varied between 0.268 and 0.738 kgCO2-eq/m3. In detail, WWTPs with AAO process, large-scale (>100 k m3/day), high load rate (80%-100%), low theoretical oxygen consumption (0.2- 0.4 kgO2/t), influent COD of 150- 250 mg/L, NH3-N of 15- 25 mg/L and discharge limits B demonstrated lower amounts of total GHG emissions than other WWTPs. Shanghai cases in this study provided a reference for future city-level WWTPs GHG management in China.
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Affiliation(s)
- Jiarui Xi
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Hui Gong
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
| | - Yujiu Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Xiaohu Dai
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Ling Chen
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
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Duan H, Zhao Y, Koch K, Wells GF, Zheng M, Yuan Z, Ye L. Insights into Nitrous Oxide Mitigation Strategies in Wastewater Treatment and Challenges for Wider Implementation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:7208-7224. [PMID: 33975433 DOI: 10.1021/acs.est.1c00840] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Nitrous oxide (N2O) emissions account for the majority of the carbon footprint of wastewater treatment plants (WWTPs). Many N2O mitigation strategies have since been developed while a holistic view is still missing. This article reviews the state-of-the-art of N2O mitigation studies in wastewater treatment. Through analyzing existing studies, this article presents the essential knowledge to guide N2O mitigations, and the logics behind mitigation strategies. In practice, mitigations are mainly carried out by aeration control, feed scheme optimization, and process optimization. Despite increasingly more studies, real implementation remains rare, which is a combined result of unclear climate change policies/incentives, as well as technical challenges. Five critical technical challenges, as well as opportunities, of N2O mitigations were identified. It is proposed that (i) quantification methods for overall N2O emissions and pathway contributions need improvement; (ii) a reliable while straightforward mathematical model is required to quantify benefits and compare mitigation strategies; (iii) tailored risk assessment needs to be conducted for WWTPs, in which more long-term full-scale trials of N2O mitigation are urgently needed to enable robust assessments of the resulting operational costs and impact on nutrient removal performance; (iv) current mitigation strategies focus on centralized WWTPs, more investigations are warranted for decentralised systems, especially decentralized activated sludge WWTPs; and (v) N2O may be mitigated by adopting novel strategies promoting N2O reduction denitrification or microorganisms that emit less N2O. Overall, we conclude N2O mitigation research is reaching a maturity while challenges still exist for a wider implementation, especially in relation to the reliability of N2O mitigation strategies and potential risks to nutrient removal performances of WWTPs.
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Affiliation(s)
- Haoran Duan
- School of Chemical Engineering, the University of Queensland, St. Lucia, Queensland 4072, Australia
- Advanced Water Management Centre (AWMC), the University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Yingfen Zhao
- School of Chemical Engineering, the University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Konrad Koch
- Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, 85748 Garching, Germany
| | - George F Wells
- Department of Civil and Environmental Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Min Zheng
- Advanced Water Management Centre (AWMC), the University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Zhiguo Yuan
- Advanced Water Management Centre (AWMC), the University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Liu Ye
- School of Chemical Engineering, the University of Queensland, St. Lucia, Queensland 4072, Australia
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Kotajima S, Koba K, Ikeda D, Terada A, Isaka K, Nishina K, Kimura Y, Makabe A, Yano M, Fujitani H, Ushiki N, Tsuneda S, Yoh M. Nitrogen and Oxygen Isotope Signatures of Nitrogen Compounds during Anammox in the Laboratory and a Wastewater Treatment Plant. Microbes Environ 2020; 35. [PMID: 33162466 PMCID: PMC7734408 DOI: 10.1264/jsme2.me20031] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Isotopic fractionation factors against 15N and 18O during anammox (anaerobic ammonia oxidization by nitrite) are critical for evaluating the importance of this process in natural environments. We performed batch incubation experiments with an anammox-dominated biomass to investigate nitrogen (N) and oxygen (O) isotopic fractionation factors during anammox and also examined apparent isotope fractionation factors during anammox in an actual wastewater treatment plant. We conducted one incubation experiment with high δ18O of water to investigate the effects of water δ18O. The N isotopic fractionation factors estimated from incubation experiments and the wastewater treatment plant were similar to previous values. We also found that the N isotopic effect (15εNXR of -77.8 to -65.9‰ and 15ΔNXR of -31.3 to -30.4‰) and possibly O isotopic effect (18εNXR of -20.6‰) for anaerobic nitrite oxidation to nitrate were inverse. We applied the estimated isotopic fractionation factors to the ordinary differential equation model to clarify whether anammox induces deviations in the δ18O vs δ15N of nitrate from a linear trajectory of 1, similar to heterotrophic denitrification. Although this deviation has been attributed to nitrite oxidation, the O isotopic fractionation factor for anammox is crucial for obtaining a more detailed understanding of the mechanisms controlling this deviation. In our model, anammox induced the trajectory of the δ18O vs δ15N of nitrate during denitrification to less than one, which strongly indicates that this deviation is evidence of nitrite oxidation by anammox under denitrifying conditions.
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Affiliation(s)
- Shotoku Kotajima
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology
| | - Keisuke Koba
- Center for Ecological Research, Kyoto University.,Institute of Agriculture, Tokyo University of Agriculture and Technology
| | - Daisuke Ikeda
- Graduate School of Engineering, Tokyo University of Agriculture and Technology
| | - Akihiko Terada
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology.,Institute of Global Innovation Research, Tokyo University of Agriculture and Technology
| | - Kazuichi Isaka
- Hitachi, Ltd.,Department of Applied Chemistry, Faculty of Science and Engineering, Toyo University
| | - Kazuya Nishina
- Center for Regional Environmental Research, National Institute of Environmental Sciences
| | | | - Akiko Makabe
- Institute of Agriculture, Tokyo University of Agriculture and Technology.,Project Team for Development of New-generation Research Protocol for Submarine Resources, Japan Agency for Marine-Earth Science and Technology.,Present address: Institute for Extra-cutting-edge Science and Technology Avant-garde Research (X-star), Super-cutting-edge Grand and Advanced Research (SUGAR) Program, Japan Agency for Marine-Earth Science and Technology
| | - Midori Yano
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology.,Center for Ecological Research, Kyoto University
| | - Hirotsugu Fujitani
- Department of Life Science and Medical Bioscience, Waseda University.,Present address: Department of Biological Sciences, Faculty of Science and Engineering, Chuo University
| | - Norisuke Ushiki
- Department of Life Science and Medical Bioscience, Waseda University
| | - Satoshi Tsuneda
- Department of Life Science and Medical Bioscience, Waseda University
| | - Muneoki Yoh
- Institute of Agriculture, Tokyo University of Agriculture and Technology
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Yan X, Zheng S, Qiu D, Yang J, Han Y, Huo Z, Su X, Sun J. Characteristics of N 2O generation within the internal micro-environment of activated sludge flocs under different dissolved oxygen concentrations. BIORESOURCE TECHNOLOGY 2019; 291:121867. [PMID: 31376671 DOI: 10.1016/j.biortech.2019.121867] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 07/18/2019] [Accepted: 07/20/2019] [Indexed: 06/10/2023]
Abstract
Nitrous oxide (N2O) is a strong greenhouse gas that is produced in significant quantities through biological nitrogen removal processes in wastewater treatment plants; however, N2O generation within the internal micro-environment of activated sludge flocs (ASFs) is poorly understood. In this study, microelectrodes and molecular techniques were employed to investigate the concentrations of N2O and other chemicals and the composition and distribution of microbes within ASFs, respectively. The results showed that N2O generation was correlated with the ASF micro-environment, and was significantly influenced by the dissolved oxygen (DO) concentration of the bulk wastewater. Equal N2O, DO, NH4+-N, and NO3--N concentrations were found in small flocs (<100 μm). By contrast, higher N2O generation rates and lower DO, NH4+-N, and NO3--N concentrations were detected in the center of large flocs (>200 μm) compared with those at their surfaces. Microbial structures of varying particle sizes were distinct and depended on the micro-environmental characteristics.
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Affiliation(s)
- Xu Yan
- School of Environment, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Henan Normal University, Xinxiang 453007, Henan, China.
| | - Shikan Zheng
- School of Environment, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Henan Normal University, Xinxiang 453007, Henan, China
| | - Dezhi Qiu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jie Yang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yunping Han
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Zhaoman Huo
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Xianfa Su
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jianhui Sun
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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11
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Vasilaki V, Massara TM, Stanchev P, Fatone F, Katsou E. A decade of nitrous oxide (N 2O) monitoring in full-scale wastewater treatment processes: A critical review. WATER RESEARCH 2019; 161:392-412. [PMID: 31226538 DOI: 10.1016/j.watres.2019.04.022] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/09/2019] [Accepted: 04/10/2019] [Indexed: 06/09/2023]
Abstract
Direct nitrous oxide (N2O) emissions during the biological nitrogen removal (BNR) processes can significantly increase the carbon footprint of wastewater treatment plant (WWTP) operations. Recent onsite measurement of N2O emissions at WWTPs have been used as an alternative to the controversial theoretical methods for the N2O calculation. The full-scale N2O monitoring campaigns help to expand our knowledge on the N2O production pathways and the triggering operational conditions of processes. The accurate N2O monitoring could help to find better process control solutions to mitigate N2O emissions of wastewater treatment systems. However, quantifying the emissions and understanding the long-term behaviour of N2O fluxes in WWTPs remains challenging and costly. A review of the recent full-scale N2O monitoring campaigns is conducted. The analysis covers the quantification and mitigation of emissions for different process groups, focusing on techniques that have been applied for the identification of dominant N2O pathways and triggering operational conditions, techniques using operational data and N2O data to identify mitigation measures and mechanistic modelling. The analysis of various studies showed that there are still difficulties in the comparison of N2O emissions and the development of emission factor (EF) databases; the N2O fluxes reported in literature vary significantly even among groups of similar processes. The results indicated that the duration of the monitoring campaigns can impact the EF range. Most N2O monitoring campaigns lasting less than one month, have reported N2O EFs less than 0.3% of the N-load, whereas studies lasting over a year have a median EF equal to 1.7% of the N-load. The findings of the current study indicate that complex feature extraction and multivariate data mining methods can efficiently convert wastewater operational and N2O data into information, determine complex relationships within the available datasets and boost the long-term understanding of the N2O fluxes behaviour. The acquisition of reliable full-scale N2O monitoring data is significant for the calibration and validation of the mechanistic models -describing the N2O emission generation in WWTPs. They can be combined with the multivariate tools to further enhance the interpretation of the complicated full-scale N2O emission patterns. Finally, a gap between the identification of effective N2O mitigation strategies and their actual implementation within the monitoring and control of WWTPs has been identified. This study concludes that there is a further need for i) long-term N2O monitoring studies, ii) development of data-driven methodological approaches for the analysis of WWTP operational and N2O data, and iii) better understanding of the trade-offs among N2O emissions, energy consumption and system performance to support the optimization of the WWTPs operation.
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Affiliation(s)
- V Vasilaki
- Department of Civil & Environmental Engineering, Brunel University London, Uxbridge Campus, Middlesex, UB8 3PH, Uxbridge, UK
| | - T M Massara
- Institute of Environment, Health and Societies, Brunel University London, Uxbridge Campus, Middlesex, UB8 3PH, Uxbridge, UK
| | - P Stanchev
- Department of Civil & Environmental Engineering, Brunel University London, Uxbridge Campus, Middlesex, UB8 3PH, Uxbridge, UK
| | - F Fatone
- Department of Science and Engineering of Materials, Environment and City Planning, Faculty of Engineering, Polytechnic University of Marche, Ancona, Italy
| | - E Katsou
- Department of Civil & Environmental Engineering, Brunel University London, Uxbridge Campus, Middlesex, UB8 3PH, Uxbridge, UK; Institute of Environment, Health and Societies, Brunel University London, Uxbridge Campus, Middlesex, UB8 3PH, Uxbridge, UK.
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12
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Chai H, Deng S, Zhou X, Su C, Xiang Y, Yang Y, Shao Z, Gu L, Xu X, Ji F, He Q. Nitrous oxide emission mitigation during low-carbon source wastewater treatment: effect of external carbon source supply strategy. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:23095-23107. [PMID: 31183761 DOI: 10.1007/s11356-019-05516-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 05/17/2019] [Indexed: 06/09/2023]
Abstract
Nitrous oxide (N2O) generated during biological nitrogen removal in wastewater treatment processes has contributed an important proportion to the global warming effect. To evaluate the possibility of N2O emission mitigating by changing carbon source supply strategies, nitrogen transformation characteristics and N2O emissions with methanol one-time dosing and step dosing were investigated. Two sets of laboratory-scale sequencing batch biofilm reactors (SBBRs) were conducted to treat real domestic wastewater with low carbon source. The results revealed that reactors with methanol step dosing showed a lower N2O emission of 0.0402 ± 0.0016 mg/(L·h), together with a higher total nitrogen and ammonia nitrogen removal efficiencies of 83.30% ± 1.21 and 93.45% ± 1.20, respectively. While N2O emission from conventional one-time dosing reactors was 0.0741 ± 0.0025 mg/(L·h), total nitrogen and ammonia nitrogen removal efficiencies were 75.71% ± 0.54 and 88.45% ± 0.59, respectively. The N2O emission factor of SBBR was reduced from 6.26% ± 0.21 to 3.40% ± 0.14 with methanol step dosing. Moreover, nitrification rates in aerobic phases were reduced, while denitrification rates in anoxic phases were elevated. Hence, carbon source step dosing enhanced nitrogen removal and reduced N2O emission compared with one-time dosing, which is a simply achievable strategy for N2O emission reduction in highly automated systems like wastewater treatment plants.
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Affiliation(s)
- Hongxiang Chai
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, People's Republic of China.
- National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing, 400045, People's Republic of China.
| | - Siping Deng
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, People's Republic of China
- National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing, 400045, People's Republic of China
| | - Xiaoyuan Zhou
- College of Physics, Chongqing University, Chongqing, 401331, People's Republic of China
| | - Chuanrong Su
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, People's Republic of China
- National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing, 400045, People's Republic of China
| | - Yu Xiang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, People's Republic of China
- National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing, 400045, People's Republic of China
| | - Yan Yang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, People's Republic of China
- National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing, 400045, People's Republic of China
| | - Zhiyu Shao
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, People's Republic of China
- National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing, 400045, People's Republic of China
| | - Li Gu
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, People's Republic of China
- National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing, 400045, People's Republic of China
| | - Xuan Xu
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, People's Republic of China
- National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing, 400045, People's Republic of China
| | - Fangying Ji
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, People's Republic of China
- National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing, 400045, People's Republic of China
| | - Qiang He
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, People's Republic of China
- National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing, 400045, People's Republic of China
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13
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Tumendelger A, Alshboul Z, Lorke A. Methane and nitrous oxide emission from different treatment units of municipal wastewater treatment plants in Southwest Germany. PLoS One 2019; 14:e0209763. [PMID: 30608974 PMCID: PMC6319721 DOI: 10.1371/journal.pone.0209763] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 12/11/2018] [Indexed: 11/27/2022] Open
Abstract
We measured the atmospheric emission rates of methane (CH4) and nitrous oxide (N2O) in two wastewater treatment plants in Southwest Germany, which apply different treatment technologies. Dissolved gas concentrations and fluxes were measured during all processing steps as well as in the discharge receiving streams. N2O isotopocule analysis revealed that NH2OH oxidation during nitrification contributed 86–96% of the N2O production in the nitrification tank, whereas microbial denitrification was the main production pathway in the denitrification tank in a conventional activated sludge (CAS) system. During wastewater treatment using a modified Ludzack-Ettinger system (MLE) with energy recovery, N2O was predominantly produced by the NO2- reduction by nitrifier-denitrification process. For both systems, N2O emissions were low, with emission factors of 0.008% and 0.001% for the MLE and the CAS system, respectively. In the effluent-receiving streams, bacterial denitrification and nitrification contributed nearly equally to N2O production. The CH4 emission from the MLE system was estimated as 118.1 g-C d-1, which corresponds to an emission factor of 0.004%, and was three times lower than the emission from the CAS system with 0.01%.
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Affiliation(s)
- Azzaya Tumendelger
- Institute of Chemistry and Chemical Technology, Mongolian Academy of Sciences, Bayanzurkh district, Ulaanbaatar, Mongolia
- Institute for Environmental Sciences, University of Koblenz-Landau, Landau, Germany
- * E-mail:
| | - Zeyad Alshboul
- Institute for Environmental Sciences, University of Koblenz-Landau, Landau, Germany
- Civil Engineering Department, Faculty of Engineering, Applied Science University, Amman, Jordan
| | - Andreas Lorke
- Institute for Environmental Sciences, University of Koblenz-Landau, Landau, Germany
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14
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Massara TM, Malamis S, Guisasola A, Baeza JA, Noutsopoulos C, Katsou E. A review on nitrous oxide (N 2O) emissions during biological nutrient removal from municipal wastewater and sludge reject water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 596-597:106-123. [PMID: 28426987 DOI: 10.1016/j.scitotenv.2017.03.191] [Citation(s) in RCA: 150] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Revised: 03/19/2017] [Accepted: 03/19/2017] [Indexed: 05/20/2023]
Abstract
Nitrous oxide (N2O) is an important pollutant which is emitted during the biological nutrient removal (BNR) processes of wastewater treatment. Since it has a greenhouse effect which is 265 times higher than carbon dioxide, even relatively small amounts can result in a significant carbon footprint. Biological nitrogen (N) removal conventionally occurs with nitrification/denitrification, yet also through advanced processes such as nitritation/denitritation and completely autotrophic N-removal. The microbial pathways leading to the N2O emission include hydroxylamine oxidation and nitrifier denitrification, both activated by ammonia oxidizing bacteria, and heterotrophic denitrification. In this work, a critical review of the existing literature on N2O emissions during BNR is presented focusing on the most contributing parameters. Various factors increasing the N2O emissions either per se or combined are identified: low dissolved oxygen, high nitrite accumulation, low chemical oxygen demand to nitrogen ratio, slow growth of denitrifying bacteria, uncontrolled pH and temperature. However, there is no common pattern in reporting the N2O generation amongst the cited studies, a fact that complicates its evaluation. When simulating N2O emissions, all microbial pathways along with the potential contribution of abiotic N2O production during wastewater treatment at different dissolved oxygen/nitrite levels should be considered. The undeniable validation of the robustness of such models calls for reliable quantification techniques which simultaneously describe dissolved and gaseous N2O dynamics. Thus, the choice of the N-removal process, the optimal selection of operational parameters and the establishment of validated dynamic models combining multiple N2O pathways are essential for studying the emissions mitigation.
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Affiliation(s)
- Theoni Maria Massara
- Department of Mechanical, Aerospace and Civil Engineering, Brunel University London, Uxbridge Campus, Middlesex, UB8 3PH, Uxbridge, UK; Institute of Environment, Health and Societies, Brunel University London, Kingston Lane, Middlesex, UB8 3PH, Uxbridge, UK
| | - Simos Malamis
- Department of Water Resources and Environmental Engineering, School of Civil Engineering, National Technical University of Athens, 5 Iroon Polytechniou St., Zographou Campus, 15780 Athens, Greece
| | - Albert Guisasola
- GENOCOV, Departament d'Enginyeria Química, Biològica i Ambiental, Escola d'Enginyeria, Universitat Autònoma de Barcelona, Cerdanyola del Vallés (Barcelona), 08193 Barcelona, Spain
| | - Juan Antonio Baeza
- GENOCOV, Departament d'Enginyeria Química, Biològica i Ambiental, Escola d'Enginyeria, Universitat Autònoma de Barcelona, Cerdanyola del Vallés (Barcelona), 08193 Barcelona, Spain
| | - Constantinos Noutsopoulos
- Department of Water Resources and Environmental Engineering, School of Civil Engineering, National Technical University of Athens, 5 Iroon Polytechniou St., Zographou Campus, 15780 Athens, Greece
| | - Evina Katsou
- Department of Mechanical, Aerospace and Civil Engineering, Brunel University London, Uxbridge Campus, Middlesex, UB8 3PH, Uxbridge, UK; Institute of Environment, Health and Societies, Brunel University London, Kingston Lane, Middlesex, UB8 3PH, Uxbridge, UK.
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15
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Boiocchi R, Gernaey KV, Sin G. A novel fuzzy-logic control strategy minimizing N 2O emissions. WATER RESEARCH 2017; 123:479-494. [PMID: 28689131 DOI: 10.1016/j.watres.2017.06.074] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 05/30/2017] [Accepted: 06/26/2017] [Indexed: 06/07/2023]
Abstract
A novel control strategy for achieving low N2O emissions and low effluent NH4+ concentration is here proposed. The control strategy uses the measurements of ammonium and nitrate concentrations in inlet and outlet of the aerobic zone of a wastewater treatment plant to calculate a ratio indicating the balance among the microbial groups. More specifically, the ratio will indicate if there is a complete nitrification. In case nitrification is not complete, the controller will adjust the aeration level of the plant in order to inhibit the production of N2O from AOB and HB denitrification. The controller was implemented using the fuzzy logic approach. It was comprehensively tested for different model structures and different sets of model parameters with regards to its ability of mitigating N2O emissions for future applications in real wastewater treatment plants. It is concluded that the control strategy is useful for those plants having AOB denitrification as the main N2O producing process. However, in treatment plants having incomplete NH2OH oxidation as the main N2O producing pathway, a cascade controller configuration adapting the oxygen supply to respect only the effluent ammonium concentration limits was found to be more effective to ensure low N2O emissions.
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Affiliation(s)
- Riccardo Boiocchi
- Process and Systems Engineering Center (PROSYS), Department of Chemical and Biochemical Engineering, Technical University of Denmark, Building 229, 2800 Kgs. Lyngby, Denmark
| | - Krist V Gernaey
- Process and Systems Engineering Center (PROSYS), Department of Chemical and Biochemical Engineering, Technical University of Denmark, Building 229, 2800 Kgs. Lyngby, Denmark
| | - Gürkan Sin
- Process and Systems Engineering Center (PROSYS), Department of Chemical and Biochemical Engineering, Technical University of Denmark, Building 229, 2800 Kgs. Lyngby, Denmark.
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16
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Duan H, Ye L, Erler D, Ni BJ, Yuan Z. Quantifying nitrous oxide production pathways in wastewater treatment systems using isotope technology - A critical review. WATER RESEARCH 2017; 122:96-113. [PMID: 28595125 DOI: 10.1016/j.watres.2017.05.054] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 05/01/2017] [Accepted: 05/25/2017] [Indexed: 06/07/2023]
Abstract
Nitrous oxide (N2O) is an important greenhouse gas and an ozone-depleting substance which can be emitted from wastewater treatment systems (WWTS) causing significant environmental impacts. Understanding the N2O production pathways and their contribution to total emissions is the key to effective mitigation. Isotope technology is a promising method that has been applied to WWTS for quantifying the N2O production pathways. Within the scope of WWTS, this article reviews the current status of different isotope approaches, including both natural abundance and labelled isotope approaches, to N2O production pathways quantification. It identifies the limitations and potential problems with these approaches, as well as improvement opportunities. We conclude that, while the capabilities of isotope technology have been largely recognized, the quantification of N2O production pathways with isotope technology in WWTS require further improvement, particularly in relation to its accuracy and reliability.
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Affiliation(s)
- Haoran Duan
- Advanced Water Management Centre, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Liu Ye
- School of Chemical Engineering, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Dirk Erler
- Centre for Coastal Biogeochemistry, School of Environmental Science and Engineering, Southern Cross University, Lismore, NSW 2480 Australia
| | - Bing-Jie Ni
- Advanced Water Management Centre, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Zhiguo Yuan
- Advanced Water Management Centre, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia.
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17
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Toyoda S, Yoshida N, Koba K. Isotopocule analysis of biologically produced nitrous oxide in various environments. MASS SPECTROMETRY REVIEWS 2017; 36:135-160. [PMID: 25869149 DOI: 10.1002/mas.21459] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 01/13/2015] [Accepted: 01/13/2015] [Indexed: 06/04/2023]
Abstract
Natural abundance ratios of isotopocules, molecules that have the same chemical constitution and configuration, but that only differ in isotope substitution, retain a record of a compound's origin and reactions. A method to measure isotopocule ratios of nitrous oxide (N2 O) has been established by using mass analysis of molecular ions and fragment ions. The method has been applied widely to environmental samples from the atmosphere, ocean, fresh water, soils, and laboratory-simulation experiments. Results show that isotopocule ratios, particularly the 15 N-site preference (difference between isotopocule ratios 14 N15 N16 O/14 N14 N16 O and 15 N14 N16 O/14 N14 N16 O), have a wide range that depends on their production and consumption processes. Observational and laboratory studies of N2 O related to biological processes are reviewed and discussed to elucidate complex material cycles of this trace gas, which causes global warming and stratospheric ozone depletion. © 2015 Wiley Periodicals, Inc. Mass Spec Rev 36:135-160, 2017.
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Affiliation(s)
- Sakae Toyoda
- Department of Environmental Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan
| | - Naohiro Yoshida
- Department of Environmental Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan
- Department of Environmental Chemistry and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Keisuke Koba
- Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-City, Tokyo 183-8509, Japan
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18
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Song K, Suenaga T, Harper WF, Hori T, Riya S, Hosomi M, Terada A. Effects of aeration and internal recycle flow on nitrous oxide emissions from a modified Ludzak-Ettinger process fed with glycerol. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:19562-19570. [PMID: 26268623 DOI: 10.1007/s11356-015-5129-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 07/27/2015] [Indexed: 06/04/2023]
Abstract
Nitrous oxide (N2O) is emitted from a modified Ludzak-Ettinger (MLE) process, as a primary activated sludge system, which requires mitigation. The effects of aeration rates and internal recycle flow (IRF) ratios on N2O emission were investigated in an MLE process fed with glycerol. Reducing the aeration rate from 1.5 to 0.5 L/min increased gaseous the N2O concentration from the aerobic tank and the dissolved N2O concentration in the anoxic tank by 54.4 and 53.4 %, respectively. During the period of higher aeration, the N2O-N conversion ratio was 0.9 % and the potential N2O reducers were predominantly Rhodobacter, which accounted for 21.8 % of the total population. Increasing the IRF ratio from 3.6 to 7.2 decreased the N2O emission rate from the aerobic tank and the dissolved N2O concentration in the anoxic tank by 56 and 48 %, respectively. This study suggests effective N2O mitigation strategies for MLE systems.
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Affiliation(s)
- Kang Song
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo, 184-8588, Japan
- Research Fellow of Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo, 102-0083, Japan
| | - Toshikazu Suenaga
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo, 184-8588, Japan
| | - Willie F Harper
- Department of Systems Engineering and Management, Air Force Institute of Technology, Wright-Patterson Air Force Base, Dayton, OH, 45433, USA
| | - Tomoyuki Hori
- National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, 305-8568, Japan
| | - Shohei Riya
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo, 184-8588, Japan
| | - Masaaki Hosomi
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo, 184-8588, Japan
| | - Akihiko Terada
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka, Koganei, Tokyo, 184-8588, Japan.
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19
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Brotto AC, Li H, Dumit M, Gabarró J, Colprim J, Murthy S, Chandran K. Characterization and mitigation of nitrous oxide (N2O) emissions from partial and full-nitrification BNR processes based on post-anoxic aeration control. Biotechnol Bioeng 2015; 112:2241-7. [PMID: 25943701 DOI: 10.1002/bit.25635] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 04/16/2015] [Accepted: 04/27/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Ariane Coelho Brotto
- Department of Earth and Environmental Engineering; Columbia University; 500 West 120th Street New York New York 10027
| | - Huosheng Li
- Department of Earth and Environmental Engineering; Columbia University; 500 West 120th Street New York New York 10027
- College of Environment and Energy; Guangzhou Higher Education Mega Center; South China University of Technology; China
| | - Muriel Dumit
- Department of Civil & Environmental Engineering; The George Washington University; Washington District of Columbia 20052
| | - Jordi Gabarró
- LEQUIA; Institute of the Environment; University of Girona; Campus Montilivi; Catalonia Spain
| | - Jesús Colprim
- LEQUIA; Institute of the Environment; University of Girona; Campus Montilivi; Catalonia Spain
| | - Sudhir Murthy
- District of Columbia Water and Sewer Authority; Washington District of Columbia
| | - Kartik Chandran
- Department of Earth and Environmental Engineering; Columbia University; 500 West 120th Street New York New York 10027
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20
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Snider DM, Venkiteswaran JJ, Schiff SL, Spoelstra J. From the ground up: global nitrous oxide sources are constrained by stable isotope values. PLoS One 2015; 10:e0118954. [PMID: 25811179 PMCID: PMC4374930 DOI: 10.1371/journal.pone.0118954] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 01/08/2015] [Indexed: 11/18/2022] Open
Abstract
Rising concentrations of nitrous oxide (N2O) in the atmosphere are causing widespread concern because this trace gas plays a key role in the destruction of stratospheric ozone and it is a strong greenhouse gas. The successful mitigation of N2O emissions requires a solid understanding of the relative importance of all N2O sources and sinks. Stable isotope ratio measurements (δ15N-N2O and δ18O-N2O), including the intramolecular distribution of 15N (site preference), are one way to track different sources if they are isotopically distinct. ‘Top-down’ isotope mass-balance studies have had limited success balancing the global N2O budget thus far because the isotopic signatures of soil, freshwater, and marine sources are poorly constrained and a comprehensive analysis of global N2O stable isotope measurements has not been done. Here we used a robust analysis of all available in situ measurements to define key global N2O sources. We showed that the marine source is isotopically distinct from soil and freshwater N2O (the continental source). Further, the global average source (sum of all natural and anthropogenic sources) is largely controlled by soils and freshwaters. These findings substantiate past modelling studies that relied on several assumptions about the global N2O cycle. Finally, a two-box-model and a Bayesian isotope mixing model revealed marine and continental N2O sources have relative contributions of 24–26% and 74–76% to the total, respectively. Further, the Bayesian modeling exercise indicated the N2O flux from freshwaters may be much larger than currently thought.
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Affiliation(s)
- David M. Snider
- National Water Research Institute, Canada Centre for Inland Waters, Environment Canada, Burlington, ON, L7R 4A6, Canada
- * E-mail: (DMS); (JJV)
| | - Jason J. Venkiteswaran
- Department of Geography and Environmental Studies, Wilfrid Laurier University, Waterloo, ON, N2L 3C5, Canada
- Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
- * E-mail: (DMS); (JJV)
| | - Sherry L. Schiff
- Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - John Spoelstra
- National Water Research Institute, Canada Centre for Inland Waters, Environment Canada, Burlington, ON, L7R 4A6, Canada
- Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
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