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Hua H, Jiang S, Yuan Z, Liu X, Zhang Y, Cai Z. Advancing greenhouse gas emission factors for municipal wastewater treatment plants in China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 295:118648. [PMID: 34890748 DOI: 10.1016/j.envpol.2021.118648] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 10/09/2021] [Accepted: 12/05/2021] [Indexed: 06/13/2023]
Abstract
Estimations of greenhouse gas (GHG) emissions from municipal wastewater treatment plants (MWTPs) remain significant uncertainties in China owing to a lack of reliable emission factors (EFs). This study developed a framework to obtain multi-level (technology, province, and nation) GHG EFs of MWTPs using a database containing 3107 MWTPs in China and published site-specific monitoring data. Results show that GHG EFs of different technologies range widely from 180.0 to 615.7 g CO2-eq/t wastewater, and significant differences are also observed among different provinces in China (190.5-600.3 g CO2-eq/t wastewater), which are generally lower than the previous estimates. It confirms the importance of more detailed technology classification and considering the technological disparity of different provinces in refining GHG estimations of MWTPs. To test the feasibility of the developed EFs, we compared GHG emissions from MWTPs based on multi-level EFs at different spatial and temporal scales. Similar estimation results imply that selecting corresponding EF depending on the availability of activity data would simplify GHG estimations of MWTPs without sacrificing much accuracy. This study contributes a set of well-developed EFs to improve the estimates of GHG emissions from MWTPs, and also offers a method to develop GHG EFs for other sectors.
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Affiliation(s)
- Hui Hua
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - Songyan Jiang
- School of Management Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, 210044, PR China
| | - Zengwei Yuan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China.
| | - Xuewei Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - You Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - Zican Cai
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
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Chun Y, Kim D, Hattori S, Toyoda S, Yoshida N, Huh J, Lim JH, Park JH. Temperature control on wastewater and downstream nitrous oxide emissions in an urbanized river system. WATER RESEARCH 2020; 187:116417. [PMID: 32987292 DOI: 10.1016/j.watres.2020.116417] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/04/2020] [Accepted: 09/09/2020] [Indexed: 06/11/2023]
Abstract
Although eutrophic urban rivers receiving loads of wastewater represent an important anthropogenic source of N2O, little is known as to how temperature and other environmental factors affect temporal variations in N2O emissions from wastewater treatment plants (WWTPs) and downstream rivers. Two-year monitoring at a WWTP and five river sites was complemented with available water quality data, laboratory incubations, and stable isotopes in N2O and NO3- to explore how wastewater effluents interact with seasonal changes in environmental conditions to affect downstream metabolic processes and N2O emissions from the lower Han River traversing the megacity Seoul. Water quality data from four WWTPs revealed significant inverse relationships between water temperature and the concentrations or fluxes of total N (TN) in effluents. Increased TN fluxes at low temperatures concurred with N2O surges in WWTP effluents and downstream rivers, counteracting the long-term decline in TN fluxes resulting from enhanced wastewater treatments. Incubation experiments with river water and sediment, in isolation or combined, implied the hypoxic winter sediment as a large source of N2O, whereas the anoxic summer sediment produced a smaller amount of N2O only when it was added with oxic water. For both WWTP effluents and downstream rivers, bulk isotope ratios and intramolecular distribution of 15N in N2O distinctly differed between summer and winter, indicating incomplete denitrification in the hypoxic sediment at low temperatures as a primary downstream source adding to WWTP-derived N2O. Winter surges in wastewater TN and sediment N2O release highlight temperature variability as an underappreciated control over anthropogenic N2O emissions from increasingly urbanized river systems worldwide.
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Affiliation(s)
- Yewon Chun
- Department of Environmental Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Dohee Kim
- Department of Environmental Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Shohei Hattori
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, Yokohama 226-8502, Japan
| | - Sakae Toyoda
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, Yokohama 226-8502, Japan
| | - Naohiro Yoshida
- Department of Chemical Science and Engineering, Tokyo Institute of Technology, Yokohama 226-8502, Japan; Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo 152-8550, Japan
| | - Jinhee Huh
- Department of Environmental Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Ju-Hee Lim
- Department of Environmental Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Ji-Hyung Park
- Department of Environmental Science and Engineering, Ewha Womans University, Seoul 03760, Republic of Korea.
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3
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Qi WK, Song Y, Peng Y, Li YY. Greenhouse gas emissions from a sewage contact oxidation emergency treatment plant after destruction by an earthquake and tsunami. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 687:634-641. [PMID: 31220717 DOI: 10.1016/j.scitotenv.2019.06.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 05/29/2019] [Accepted: 06/02/2019] [Indexed: 06/09/2023]
Abstract
Emissions of greenhouse gases (GHGs) from a full-scale contact oxidation emergency sewage treatment plant (STP) in Japan that was damaged by an earthquake and a tsunami were measured. The open chamber (OC) and closed chamber (CC) methods were used to sample the gases emitted in the aeration tank and the settler, respectively. The dissolved gases were measured using the headspace method, and the major emissions sources in wastewater treatment were identified. The results indicated that the GHG emissions from the wastewater were 58.6 g-CO2/m3 (equivalent per cubic meter of wastewater). The CH4 emissions showed a strong negative correlation with the dissolved oxygen (DO) content. More than 98% of the GHGs were produced and stripped by the aeration tank. The CO2, CH4 and N2O emissions accounted for 73.0% (21,781 mL/m3), 17.1% (669 mL/m3) and 9.9% (10.9 mL/m3), respectively, of all GHG emissions. Approximately 1.06% of the incoming chemical oxygen demand (COD) was emitted as CH4, and 0.147% of the removed nitrogen was emitted as N2O.
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Affiliation(s)
- Wei-Kang Qi
- 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, China; Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan.
| | - Ying Song
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - 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, China
| | - Yu-You Li
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan.
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4
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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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Maktabifard M, Zaborowska E, Makinia J. Evaluating the effect of different operational strategies on the carbon footprint of wastewater treatment plants - case studies from northern Poland. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2019; 79:2211-2220. [PMID: 31318359 DOI: 10.2166/wst.2019.224] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Nowadays, low greenhouse gas (GHG) emission is expected at wastewater treatment plants (WWTPs). However, emission quantification and evaluation still faces difficulties related to data availability and uncertainty. The objective of this study was to perform carbon footprint (CF) analysis for two municipal WWTPs located in northern Poland. Slupsk WWTP is a large biological nutrient removal (BNR) facility (250,000 PE) which benefits from on-site electricity production from biogas. The other studied plant is a medium-size BNR facility in Starogard (60,000 PE). In this WWTP, all the required electricity was provided from the grid. Both wastewater systems were composed of activated sludge, with differences in the nutrient removal efficiency and sludge treatment line. The CF calculations were based on empirical models considering various categories of input parameters, afterwards summing up the emissions expressed in CO2 equivalents (CO2e). After sensitivity analysis, significant contributors to GHG emissions were identified. The total specific CF of the Slupsk and the Starogard WWTP was 17.3 and 38.8 CO2e per population equivalent (PE), respectively. In both cases, sludge management, electricity consumption and direct emissions from wastewater treatment were found to significantly influence the CF. A substantial share of the total CF originated from indirect emissions, primarily caused by the energy consumption. This negative impact can be partially overcome by increasing the share of renewable energy sources. Reduction of over 30% in the total CF could be achieved while applying energy recovery from biogas by combined heat and power plants. Farmland and farmland after composting were found to be the most appropriate strategies for sludge management. They could create a CF credit (8% of the total CF) as a result of substituting a synthetic fertilizer. Reliable full-scale measurements of N2O emissions from wastewater treatment are recommended due to high uncertainty in CF estimation based on fixed emission factors (EFs). While applying the lowest and the highest N2O EFs reported in the literature, the total CF would change even by 2-3 times.
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Affiliation(s)
- M Maktabifard
- Faculty of Civil and Environmental Engineering, Gdansk University of Technology, Narutowicza Street 11/12, 80-233 Gdansk, Poland E-mail:
| | - E Zaborowska
- Faculty of Civil and Environmental Engineering, Gdansk University of Technology, Narutowicza Street 11/12, 80-233 Gdansk, Poland E-mail:
| | - J Makinia
- Faculty of Civil and Environmental Engineering, Gdansk University of Technology, Narutowicza Street 11/12, 80-233 Gdansk, Poland E-mail:
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Caniani D, Caivano M, Pascale R, Bianco G, Mancini IM, Masi S, Mazzone G, Firouzian M, Rosso D. CO 2 and N 2O from water resource recovery facilities: Evaluation of emissions from biological treatment, settling, disinfection, and receiving water body. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 648:1130-1140. [PMID: 30340259 DOI: 10.1016/j.scitotenv.2018.08.150] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 08/09/2018] [Accepted: 08/11/2018] [Indexed: 06/08/2023]
Abstract
Water resource recovery facilities (WRRFs) contribute to climate change and air pollution, as they are anthropogenic potential sources of direct and indirect emission of greenhouse gases (GHGs). Studies concerning the monitoring and accounting for GHG emissions from WRRFs are of increasing interest. In this study, the floating hood technique for gas collection was coupled with the off-gas method to monitor and apportion nitrous oxide (N2O) and carbon dioxide (CO2) emissions from both aerated and non-aerated tanks in a municipal water resource recovery facility, in order to investigate its carbon footprint (CFP). To our knowledge, this is the first time that the chamber technique was applied to evaluate gas fluxes from the settler, where an emission factor (EF) of 4.71 ∗ 10-5 kgCO2,eq kgbCOD-1 was found. Interesting results were found in the disinfection unit, which was the major contributor to direct N2O emissions (with a specific emission factor of 0.008 kgCO2,eq kgbCOD-1), due to the chemical interaction between hydroxylamine and the disinfectant agent (hypochlorite). The specific emission factor of the biological aerated tank was 0.00112 kgCO2,eq kgbCOD-1. The average direct CO2 emission was equal to 0.068 kgCO2 kgbCOD-1 from the activated sludge tank and to 0.00017 kgCO2 kgbCOD-1 from the secondary clarifier. Therefore, taking into account the contribution of both direct N2O and CO2 emissions, values of 0.069 kgCO2,eq kgbCOD-1, 0.008 kgCO2,eq kgbCOD-1 and 0.00022 kgCO2,eq kgbCOD-1, were found for the net CFP of the aerated compartment, the disinfection unit and the clarifier, respectively. The plant energy Footprint (eFP) was also evaluated, confirming that the aeration system is the major contributor to energy consumption, as well as to indirect CO2 emission, with a specific eFP of 1.49 kWh kgbCOD-1.
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Affiliation(s)
- D Caniani
- Engineering School, University of Basilicata, viale dell'Ateneo Lucano 10, 85100 Potenza, Italy.
| | - M Caivano
- Engineering School, University of Basilicata, viale dell'Ateneo Lucano 10, 85100 Potenza, Italy
| | - R Pascale
- Engineering School, University of Basilicata, viale dell'Ateneo Lucano 10, 85100 Potenza, Italy
| | - G Bianco
- Dipartimento di Scienze, University of Basilicata, viale dell'Ateneo Lucano 10, 85100 Potenza, Italy
| | - I M Mancini
- Engineering School, University of Basilicata, viale dell'Ateneo Lucano 10, 85100 Potenza, Italy
| | - S Masi
- Engineering School, University of Basilicata, viale dell'Ateneo Lucano 10, 85100 Potenza, Italy
| | - G Mazzone
- Engineering School, University of Basilicata, viale dell'Ateneo Lucano 10, 85100 Potenza, Italy
| | - M Firouzian
- Civil & Environmental Engineering Department, University of California, Irvine, CA 92697-2175, USA
| | - D Rosso
- Civil & Environmental Engineering Department, University of California, Irvine, CA 92697-2175, USA; Water-Energy Nexus Center, University of California, Irvine, CA 92697-2175, USA
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Fries AE, Schifman LA, Shuster WD, Townsend-Small A. Street-level emissions of methane and nitrous oxide from the wastewater collection system in Cincinnati, Ohio. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 236:247-256. [PMID: 29414346 PMCID: PMC6537879 DOI: 10.1016/j.envpol.2018.01.076] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 01/20/2018] [Accepted: 01/22/2018] [Indexed: 06/08/2023]
Abstract
Recent studies have indicated that urban streets can be hotspots for emissions of methane (CH4) from leaky natural gas lines, particularly in cities with older natural gas distribution systems. The objective of the current study was to determine whether leaking sewer pipes could also be a source of street-level CH4 as well as nitrous oxide (N2O) in Cincinnati, Ohio, a city with a relatively new gas pipeline network. To do this, we measured the carbon (δ13C) and hydrogen (δ2H) stable isotopic composition of CH4 to distinguish between biogenic CH4 from sewer gas and thermogenic CH4 from leaking natural gas pipelines and measured CH4 and N2O flux rates and concentrations at sites from a previous study of street-level CH4 enhancements (77 out of 104 sites) as well as additional sites found through surveying sewer grates and utility manholes (27 out of 104 sites). The average isotopic signatures for δ13C-CH4 and δ2H-CH4 were -48.5‰ ± 6.0‰ and -302‰ ± 142‰. The measured flux rates ranged from 0.0 to 282.5 mg CH4 day-1 and 0.0-14.1 mg N2O day-1 (n = 43). The average CH4 and N2O concentrations measured in our study were 4.0 ± 7.6 ppm and 392 ± 158 ppb, respectively (n = 104). 72% of sites where fluxes were measured were a source of biogenic CH4. Overall, 47% of the sampled sites had biogenic CH4, while only 13% of our sites had solely thermogenic CH4. The other sites were either a source of both biogenic and thermogenic CH4 (13%), and a relatively large portion of sites had an unresolved source (29%). Overall, this survey of emissions across a large urban area indicates that production and emission of biogenic CH4 and N2O is considerable, although CH4 fluxes are lower than those reported for cities with leaky natural gas distribution systems.
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Affiliation(s)
- Anastasia E Fries
- Department of Geology, University of Cincinnati, 500 Geology-Physics Building, 345 Clifton Court, Cincinnati, OH, 45221, USA
| | - Laura A Schifman
- U.S. Environmental Protection Agency, National Risk Management Research Laboratory, 26 W. Martin Luther King Dr., Cincinnati, OH, 45268, USA
| | - William D Shuster
- U.S. Environmental Protection Agency, National Risk Management Research Laboratory, 26 W. Martin Luther King Dr., Cincinnati, OH, 45268, USA
| | - Amy Townsend-Small
- Department of Geology, University of Cincinnati, 500 Geology-Physics Building, 345 Clifton Court, Cincinnati, OH, 45221, USA.
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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: 49] [Impact Index Per Article: 7.0] [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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9
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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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10
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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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11
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Schneider AG, Townsend-Small A, Rosso D. Impact of direct greenhouse gas emissions on the carbon footprint of water reclamation processes employing nitrification-denitrification. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 505:1166-73. [PMID: 25461114 DOI: 10.1016/j.scitotenv.2014.10.060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2014] [Revised: 10/05/2014] [Accepted: 10/19/2014] [Indexed: 05/12/2023]
Abstract
Water reclamation has the potential to reduce water supply demands from aquifers and more energy-intensive water production methods (e.g., seawater desalination). However, water reclamation via biological nitrification-denitrification is also associated with the direct emission of the greenhouse gases (GHGs) CO₂, N₂O, and CH₄. We quantified these direct emissions from the nitrification-denitrification reactors of a water reclamation plant in Southern California, and measured the (14)C content of the CO₂ to distinguish between short- and long-lived carbon. The total emissions were 1.5 (±0.2) g-fossil CO₂ m(-3) of wastewater treated, 0.5 (±0.1) g-CO₂-eq of CH₄ m(-3), and 1.8 (±0.5) g-CO₂-eq of N₂O m(-3), for a total of 3.9 (±0.5) g-CO₂-eqm(-3). This demonstrated that water reclamation can be a source of GHGs from long lived carbon, and thus a candidate for GHG reduction credit. From the (14)C measurements, we found that between 11.4% and 15.1% of the CO₂ directly emitted was derived from fossil sources, which challenges past assumptions that the direct CO₂ emissions from water reclamation contain only modern carbon. A comparison of our direct emission measurements with estimates of indirect emissions from several water production methods, however, showed that the direct emissions from water reclamation constitute only a small fraction of the plant's total GHG footprint.
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Affiliation(s)
- Andrew G Schneider
- University of Cincinnati, Department of Geology, Cincinnati, OH 45221, United States.
| | - Amy Townsend-Small
- University of Cincinnati, Department of Geology, Cincinnati, OH 45221, United States; University of Cincinnati, Department of Geography, Cincinnati, OH 45221, United States
| | - Diego Rosso
- Department of Civil and Environmental Engineering, University of California, Irvine, CA 92697-2175, United States
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Tram Vo P, Ngo HH, Guo W, Zhou JL, Nguyen PD, Listowski A, Wang XC. A mini-review on the impacts of climate change on wastewater reclamation and reuse. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 494-495:9-17. [PMID: 25020098 DOI: 10.1016/j.scitotenv.2014.06.090] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 06/19/2014] [Accepted: 06/20/2014] [Indexed: 06/03/2023]
Abstract
To tackle current water insecurity concerns, wastewater reclamation and reuse have appeared as a promising candidate to conserve the valuable fresh water sources while increasing the efficiency of material utilization. Climate change, nevertheless, poses both opportunities and threats to the wastewater reclamation industry. Whereas it elevates the social perception on water-related issues and fosters an emerging water-reuse market, climate change simultaneously presents adverse impacts on the water reclamation scheme, either directly or indirectly. These effects were studied fragmentally in separate realms. Hence, this paper aims to link these studies for providing a thorough understanding about the consequences of the climate change on the wastewater reclamation and reuse. It initially summarizes contemporary treatment processes and their reuse purposes before carrying out a systematic analysis of available findings.
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Affiliation(s)
- Phuong Tram Vo
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Huu Hao Ngo
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia.
| | - Wenshan Guo
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - John L Zhou
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Phuoc Dan Nguyen
- Faculty of Environment, Ho Chi Minh City University of Technology, 268 Ly Thuong Kiet, District 10, Ho Chi Minh City, Viet Nam
| | - Andrzej Listowski
- Sydney Olympic Park Authority, 7 Figtree Drive, Sydney, NSW 2127, Australia
| | - Xiaochang C Wang
- Key Lab of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China
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Tumendelger A, Toyoda S, Yoshida N. Isotopic analysis of N2O produced in a conventional wastewater treatment system operated under different aeration conditions. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2014; 28:1883-1892. [PMID: 25088132 DOI: 10.1002/rcm.6973] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 05/21/2014] [Accepted: 06/23/2014] [Indexed: 06/03/2023]
Abstract
RATIONALE Dissolved oxygen (DO) concentration is a key parameter of nitrous oxide (N2O), a greenhouse gas, emitted from wastewater treatment systems. No study of stable isotopes has described N2O production during conventional activated sludge (CAS) treatment under different DO concentrations. METHODS Concentrations and isotope ratios, including intramolecular site preference of (15)N in NNO (SP), of N2O were measured using gas chromatography/isotope ratio mass spectrometry (GC/IRMS) for samples from seven points in a wastewater treatment plant (WWTP) operated with three aeration conditions. The δ(15)N values of NH4(+) and the δ(15)N and δ(18)O values of NO3(-) were measured using IRMS. RESULTS Aeration tank water was supersaturated with N2O. The highest value, 3700 nmol kg(-1), was observed at the aeration tank end and in settled sludge under the lowest aeration condition. About 0.03% of the influent NH4(+) was emitted as gaseous N2O at the lowest aeration condition. The conversion rate was 0.14% under the highest aeration condition. The SP values were significantly higher at the middle and end of the aeration tanks under the highest aeration condition, but were nearly zero or slightly negative under lower aeration conditions. CONCLUSIONS Under the highest aeration condition, NH2OH oxidation (nitrification) was the main contributor to N2O production at about 90% and 57%, respectively, at the aeration tank middle and end. At other sampling points, 55-63% of the N2O was produced by bacterial NO2(-) reduction (nitrifier-denitrification) with a lower nitrification contribution. For all sampling points in the lower aeration experiments, NO2(-) reduction was a major N2O production pathway.
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Affiliation(s)
- Azzaya Tumendelger
- Department of Environmental Chemistry and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8502, Japan
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Yoshida H, Mønster J, Scheutz C. Plant-integrated measurement of greenhouse gas emissions from a municipal wastewater treatment plant. WATER RESEARCH 2014; 61:108-118. [PMID: 24907479 DOI: 10.1016/j.watres.2014.05.014] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 05/11/2014] [Accepted: 05/12/2014] [Indexed: 06/03/2023]
Abstract
Wastewater treatment plants (WWTPs) contribute to anthropogenic greenhouse gas (GHG) emissions. Due to its spatial and temporal variation in emissions, whole plant characterization of GHG emissions from WWTPs face a number of obstacles. In this study, a tracer dispersion method was applied to quantify plant-integrated, real-time emissions of methane and nitrous oxides. Two mobile cavity ring-down spectroscopy sampling devices were used to record downwind gas concentrations emitted from a municipal WWTP situated in Copenhagen, Denmark. This plant is equipped to remove biological nitrogen and employs anaerobic digestion for sludge stabilization. Over the course of nine measurement campaigns, a wide range of emissions were detected: methane from 4.99 kg h(-1) up to 92.3 kg h(-1) and nitrous oxide from below the detection limit (0.37 kg h(-1)) up to 10.5 kg h(-1). High emissions were observed during periods experiencing operational problems, such as during foaming events in anaerobic digesters and during sub-optimal operation of biological nitrogen removal in the secondary treatment of wastewater. Methane emissions detected during measurement campaigns corresponded to 2.07-32.7% of the methane generated in the plant. As high as 4.27% of nitrogen entering the WWTP was emitted as nitrous oxide under the sub-optimal operation of biological treatment processes. The study shows that the unit process configuration, as well as the operation of the WWTP, determines the rate of GHG emission. The applied plant-integrated emission measurement method could be used to ease the burden of quantifying GHG emissions from WWTPs for reporting purposes and could contribute to the development of more accurate depictions of environmental performance of WWTPs.
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Affiliation(s)
- Hiroko Yoshida
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark.
| | - Jacob Mønster
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Charlotte Scheutz
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark
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Short MD, Daikeler A, Peters GM, Mann K, Ashbolt NJ, Stuetz RM, Peirson WL. Municipal gravity sewers: an unrecognised source of nitrous oxide. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 468-469:211-8. [PMID: 24029693 DOI: 10.1016/j.scitotenv.2013.08.051] [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: 04/08/2013] [Revised: 07/30/2013] [Accepted: 08/17/2013] [Indexed: 05/12/2023]
Abstract
Nitrous oxide (N2O) is a primary ozone-depleting substance and powerful greenhouse gas. N2O emissions from secondary-level wastewater treatment processes are relatively well understood as a result of intensive international research effort in recent times, yet little information exists to date on the role of sewers in wastewater management chain N2O dynamics. Here we provide the first detailed assessment of N2O levels in the untreated influent (i.e. sewer network effluent) of three large Australian metropolitan wastewater treatment plants. Contrary to current international (IPCC) guidance, results show gravity sewers to be a likely source of N2O. Results from the monitoring program revealed hydraulic flow rate as a strong driver for N2O generation in gravity sewers, with microbial processes (nitrification and possibly denitrification) implicated as the main processes responsible for its production. Results were also used to develop a presumptive emission factor for N2O in the context of municipal gravity sewers. Considering the discrepancy with current IPCC Guidelines, further work is warranted to assess the scale and dynamics of N2O production in sewers elsewhere.
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Affiliation(s)
- Michael D Short
- UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, New South Wales 2052, Australia; SA Water Centre for Water Management and Reuse, School of Natural and Built Environments, University of South Australia, Adelaide, South Australia 5095, Australia.
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Quan X, Zhang M, Lawlor PG, Yang Z, Zhan X. Nitrous oxide emission and nutrient removal in aerobic granular sludge sequencing batch reactors. WATER RESEARCH 2012; 46:4981-4990. [PMID: 22835837 DOI: 10.1016/j.watres.2012.06.031] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 05/29/2012] [Accepted: 06/19/2012] [Indexed: 06/01/2023]
Abstract
Application of aerobic granular sludge into wastewater treatment is promising due to its excellent settling ability and high microbial concentrations. However, its spatial structure could induce incomplete denitrification, leading to generation of nitrous oxide (N(2)O) - a potent greenhouse gas. Under the temperature of 14 ± 4 °C, three identical laboratory-scale aerobic granular sludge sequencing batch reactors (SBRs) were established to treat synthetic wastewater simulating a mixture of liquid pig manure digestate and municipal wastewater at three aeration rates (0.2, 0.6 and 1.0 L air/min) and three COD:N ratios (1:0.22, 1:0.15 and 1:0.11). The studies show the proportions of N(2)O emission to the influent nitrogen loading rate at the aeration rates of 0.2, 0.6 and 1.0 L air/min were 8.2%, 6.1% and 3.8% at a COD:N ratio of 1:0.22; 7.0%, 5.1% and 3.5% at a COD:N ratio of 1:0.15; and 4.4%, 2.9% and 2.2% at a COD:N ratio of 1:0.11, respectively. With NO(2)(-) as the only nitrogen source in the liquid phase, the specific N(2)O generation rates via denitrification were 1.7, 1.6 and 1.3 μg N(2)O/(g SS· min) at the aeration rates of 0.2, 0.6 and 1.0 L air/min, respectively, which were 40.9%, 44.8%, 39.9% higher than those with NO(3)(-) as the only nitrogen source, respectively. N(2)O generation by aerobic granular sludge due to NH(4)(+)-N nitrification was not sensitive to the aeration rate, and the average specific N(2)O generation rate was 0.8 ± 0.02 μg N(2)O/(g SS· min).
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Affiliation(s)
- Xiangchun Quan
- Key Laboratory of Water and Sediment Sciences of Ministry of Education, State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China
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Townsend-Small A, Tyler SC, Pataki DE, Xu X, Christensen LE. Isotopic measurements of atmospheric methane in Los Angeles, California, USA: Influence of “fugitive” fossil fuel emissions. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jd016826] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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