1
|
Chen J, Wang H, Yin W, Wang Y, Lv J, Wang A. Deciphering carbon emissions in urban sewer networks: Bridging urban sewer networks with city-wide environmental dynamics. WATER RESEARCH 2024; 256:121576. [PMID: 38608619 DOI: 10.1016/j.watres.2024.121576] [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: 12/08/2023] [Revised: 03/26/2024] [Accepted: 04/05/2024] [Indexed: 04/14/2024]
Abstract
As urbanization accelerates, understanding and managing carbon emissions from urban sewer networks have become crucial for sustainable urban water cycles. This review examines the factors influencing greenhouse gas (GHG) emissions within urban sewage systems, analyzing the complex effects between water quality, hydrodynamics, and sewer infrastructure on GHG production and emission processes. It reveals significant spatiotemporal heterogeneity in GHG emissions, particularly under long-term scenarios where flow rates and temperatures exhibit strong impacts and correlations. Given the presence of fugitive and dissolved potential GHGs, standardized monitoring and accounting methods are deemed essential. Advanced modeling techniques emerge as crucial tools for large-scale carbon emission prediction and management. The review identifies that traditional definitions and computational frameworks for carbon emission boundaries fail to fully consider the inherent heterogeneity of sewers and the dynamic changes and impacts of multi-source pollution within the sewer system during the urban water cycle. This includes irregular fugitive emissions, the influence of stormwater systems, climate change, geographical features, sewer design, and the impacts of food waste and antibiotics. Key strategies for emission management are discussed, focusing on the need for careful consideration of approaches that might inadvertently increase global emissions, such as ventilation, chemical treatments, and water management practices. The review advocates for an overarching strategy that encompasses a holistic view of carbon emissions, stressing the importance of refined emission boundary definitions, novel accounting practices, and comprehensive management schemes in line with the water treatment sector's move towards carbon neutrality. It champions the adoption of interdisciplinary, technologically advanced solutions to mitigate pollution and reduce carbon emissions, emphasizing the importance of integrating cross-scale issues and other environmentally friendly measures in future research directions.
Collapse
Affiliation(s)
- Jiaji Chen
- Key Lab of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085, China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing 101408, China; State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China; Sino-Danish Center for Education and Research, University of Chinese Academy of Sciences, Beijing 101408, China
| | - Hongcheng Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China.
| | - Wanxin Yin
- College of the Environment, Liaoning University, Shenyang 110036, China
| | - Yuqi Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Jiaqiang Lv
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China; State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - AiJie Wang
- Key Lab of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085, China; State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China.
| |
Collapse
|
2
|
Cen X, Duan H, Hu Z, Huang X, Li J, Yuan Z, Zheng M. Multifaceted benefits of magnesium hydroxide dosing in sewer systems: Impacts on downstream wastewater treatment processes. WATER RESEARCH 2023; 247:120788. [PMID: 37924683 DOI: 10.1016/j.watres.2023.120788] [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: 08/27/2023] [Revised: 10/25/2023] [Accepted: 10/26/2023] [Indexed: 11/06/2023]
Abstract
Magnesium hydroxide [Mg(OH)2] is a non-hazardous chemical widely applied in sewer systems for managing odour and corrosion. Despite its proven effectiveness in mitigating these issues, the impacts of dosing Mg(OH)2 in sewers on downstream wastewater treatment plants have not been comprehensively investigated. Through a one-year operation of laboratory-scale urban wastewater systems, including sewer reactors, sequencing batch reactors, and anaerobic sludge digesters, the findings indicated that Mg(OH)2 dosing in sewer systems had multifaceted benefits on downstream treatment processes. Compared to the control, the Mg(OH)2-dosed experimental system displayed elevated sewage pH (8.8±0.1vs 7.1±0.1), reduced sulfide concentration by 35.1%±4.9% (6.7±0.9mgSL-1), and lower methane concentration by 58.0%±4.9% (19.1±3.6mgCODL-1). Additionally, it increased alkalinity by 16.3%±2.2% (51.9±5.4mgCaCO3L-1), and volatile fatty acids concentration by 207.4%±22.2% (56.6±9.0mgCODL-1) in sewer effluent. While these changes offered limited advantages for downstream nitrogen removal in systems with sufficient alkalinity and carbon sources, significant improvements in ammonium oxidation rate and NOx reduction rate were observed in cases with limited alkalinity and carbon sources availability. Moreover, Mg(OH)2 dosing in upstream did not have any detrimental effects on anaerobic sludge digesters. Magnesium-phosphate precipitation led to a 31.7%±4.1% reduction in phosphate concertation in anaerobic digester sludge supernatant (56.1±10.4mgPL-1). The retention of magnesium in sludge increased settleability by 13.9%±1.6% and improved digested sludge dewaterability by 10.7%±5.3%. Consequently, the use of Mg(OH)2 dosing in sewers could potentially reduce downstream chemical demand and costs for carbon sources (e.g., acetate), pH adjustment and sludge dewatering.
Collapse
Affiliation(s)
- Xiaotong Cen
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane, Queensland, Australia
| | - Haoran Duan
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane, Queensland, Australia
| | - Zhetai Hu
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane, Queensland, Australia
| | - Xin Huang
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane, Queensland, Australia
| | - Jiaying Li
- Queensland Alliance for Environmental Health Sciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Zhiguo Yuan
- School of Energy and Environment, City University of Hong Kong, Hong Kong SAR, China
| | - Min Zheng
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, Brisbane, Queensland, Australia.
| |
Collapse
|
3
|
Cen X, Li J, Jiang G, Zheng M. A critical review of chemical uses in urban sewer systems. WATER RESEARCH 2023; 240:120108. [PMID: 37257296 DOI: 10.1016/j.watres.2023.120108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 05/13/2023] [Accepted: 05/20/2023] [Indexed: 06/02/2023]
Abstract
Chemical dosing is the most used strategy for sulfide and methane abatement in urban sewer systems. Although conventional physicochemical methods, such as sulfide oxidation (e.g., oxygen/nitrate), precipitation (e.g., iron salts), and pH elevation (e.g., magnesium hydroxide/sodium hydroxide) have been used since the last century, the high chemical cost, large environmental footprint, and side-effects on downstream treatment processes demand a sustainable and cost-effective alternative to these approaches. In this paper, we aimed to review the currently used chemicals and significant progress made in sustainable sulfide and methane abatement technology, including 1) the use of bio-inhibitors, 2) in situ chemical production, and 3) an effective dosing strategy. To enhance the cost-effectiveness of chemical applications in urban sewer systems, two research directions have emerged: 1) online control and optimization of chemical dosing strategies and 2) integrated use of chemicals in urban sewer and wastewater treatment systems. The integration of these approaches offers considerable system-wide benefits; however, further development and comprehensive studies are required.
Collapse
Affiliation(s)
- Xiaotong Cen
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Jiuling Li
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Guangming Jiang
- School of Civil, Mining and Environmental Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Min Zheng
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, QLD 4072, Australia.
| |
Collapse
|
4
|
Williams JP, Ars S, Vogel F, Regehr A, Kang M. Differentiating and Mitigating Methane Emissions from Fugitive Leaks from Natural Gas Distribution, Historic Landfills, and Manholes in Montréal, Canada. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:16686-16694. [PMID: 36375177 DOI: 10.1021/acs.est.2c06254] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Rapidly reducing urban methane (CH4) emissions is a critical component of strategies aimed at limiting climate change. Individual source measurements provide the details necessary to develop actionable mitigation strategies and are highly complementary to mobile surveys and other top-down methods. Here, we perform 615 individual source measurements in Montréal, Canada, to quantify CH4 emissions from historic landfills, manholes, and fugitive emissions from natural gas (NG) distribution systems. We find that in 2020, historic landfills produced 901 (452 to 1541, 95% c.i.) tons of CH4, manholes emitted 786 (32 to 2602, 95% c.i.) tons of CH4, and NG distribution systems emitted 451 (176-843, 95% c.i.) tons of CH4, placing them all within the top four CH4 sources in Montréal. Methane emissions from both historic landfills and manholes are not accounted for in any greenhouse gas inventory. We find that geochemistry alone cannot positively identify source subcategories (e.g., type of manhole or NG infrastructure) in almost all cases, although C2/C1 ratios can distinguish NG distribution sources from biogenic sources (historic landfills and manholes). Using our individual source measurement data, we show that historic landfills have the greatest potential for CH4 reductions but the highest mitigation costs, unless we target the highest emitting landfills. In contrast, CH4 emissions from manholes can be reduced at low costs, but reduction methods are commercially unavailable. For NG distribution, methods such as increasing repair rates for high-emitting industrial meters can greatly reduce mitigation costs and emissions. Overall, our results highlight the role of individual source measurements in developing actionable CH4 mitigation strategies to meet municipal, regional, and national climate action plans.
Collapse
Affiliation(s)
- James P Williams
- Department of Civil Engineering, McGill University, Montréal, Québec H3A 0G4, Canada
| | - Sebastien Ars
- Environment and Climate Change Canada, Climate Research Division, Toronto, Ontario M3H 5T4, Canada
| | - Felix Vogel
- Environment and Climate Change Canada, Climate Research Division, Toronto, Ontario M3H 5T4, Canada
| | - Amara Regehr
- Department of Civil Engineering, McGill University, Montréal, Québec H3A 0G4, Canada
| | - Mary Kang
- Department of Civil Engineering, McGill University, Montréal, Québec H3A 0G4, Canada
| |
Collapse
|
5
|
Sun Y, Ter Heijne A, Rijnaarts H, Chen WS. The effect of anode potential on electrogenesis, methanogenesis and sulfidogenesis in a simulated sewer condition. WATER RESEARCH 2022; 226:119229. [PMID: 36242938 DOI: 10.1016/j.watres.2022.119229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 09/14/2022] [Accepted: 10/07/2022] [Indexed: 06/16/2023]
Abstract
Methane emissions from the sewer system are considered to be a non-negligible source of aggravating the greenhouse effect. Meanwhile, the sewer system has long been plagued by sulfide-induced corrosion problems. This study explored the possibility of using a bioelectrochemical system to intensify the competition between electroactive bacteria, methanogens and sulfate-reducing bacteria, thereby reducing the production of methane and sulfide. Dual-chamber bioelectrochemical reactors were constructed and operated in fed-batch mode with the coexistence of Electroactive bacteria, Methanogenic archaea and Sulfate-reducing bacteria. Acetate was supplied as the sole carbon source. The results indicated that electrogenesis induced by the anode potentials of -0.42 V and -0.2 V (vs. Ag/AgCl) had advantages over methanogenesis and sulfidogenesis in consuming acetate. The stimulated electrogenesis by anode potentials resulted in a decrease in pH. Methane production was suppressed in the reactors with anode potentials of -0.42 and -0.2 V compared to open circuit controls. In contrast to methane, the capacity for sulfide production was facilitated in the reactors with the anode potentials of -0.42 V and -0.2 V compared to open circuit controls. 16s rRNA gene analysis showed that Geobacter was the most abundant genus on the anode biofilm in the anode potential-controlled reactor, while acetoclastic methanogens dominated in open circuit controls. Methanosaeta and Methanosarcina were the most abundant methanogens in open circuit controls. Collectively, our study demonstrates that the use of electrodes with anode potential control can help to control methane emissions, but could not yet prevent sulfide production, which requires further research.
Collapse
Affiliation(s)
- Yue Sun
- Environmental Technology, Wageningen University & Research, P.O. Box 17, 6700 AA, Wageningen, The Netherlands.
| | - Annemiek Ter Heijne
- Environmental Technology, Wageningen University & Research, P.O. Box 17, 6700 AA, Wageningen, The Netherlands.
| | - Huub Rijnaarts
- Environmental Technology, Wageningen University & Research, P.O. Box 17, 6700 AA, Wageningen, The Netherlands.
| | - Wei-Shan Chen
- Environmental Technology, Wageningen University & Research, P.O. Box 17, 6700 AA, Wageningen, The Netherlands.
| |
Collapse
|
6
|
Park SH, Batchelor B, Ghosh A. Gas transfer model for a multistage vortex aerator: A novel oxygen transfer system for dissolved oxygen improvement. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 319:115704. [PMID: 35842992 DOI: 10.1016/j.jenvman.2022.115704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 05/30/2022] [Accepted: 07/06/2022] [Indexed: 06/15/2023]
Abstract
A novel aerator for enhancing the oxygen transfer rate and efficiency, named multistage vortex aerator (MVA), was developed. It uses vortex flow in repeated stages to increase the gas-liquid interfacial area and to decrease the thickness of the stagnant layer at the interface between the two phases. The basic characteristics of oxygen transfer using this aerator were investigated using the American Society of Civil Engineers standard procedure. The MVA could rapidly transfer oxygen to water to a concentration higher than 40 mg/L in 60 min owing to the effect of high purity oxygen, additional pressure induced by water and gas, and vortex flow dynamics. A gas transfer model was developed for describing the non-steady state operation of the aerator. This model is based on the mass and molar balances of oxygen in gas and water. It could successfully simulate the DO change inside the aerator. This study can help better understand the oxygen transfer mechanism and evaluate the performance of the new aerator at the various temperatures, pressures, and gas compositions found in diverse environmental systems.
Collapse
Affiliation(s)
- Sung Hyuk Park
- Department of ICT Integrated Safe Ocean Smart Cities Engineering, Dong-A University, 37 Nakdong-daero Saha-gu, Busan, 49315, Republic of Korea.
| | - Bill Batchelor
- Zachry Department of Civil and Environmental Engineering, Texas A&M University, College Station, TX, 77843, United States
| | - Arnab Ghosh
- Department of Civil Engineering, Dong-A University, 37 Nakdong-daero Saha-gu, Busan, 49315, Republic of Korea
| |
Collapse
|
7
|
Zhang G, Pang Y, Zhou Y, Zhang Y, Zhu DZ. Effect of dissolved oxygen on N 2O release in the sewer system during controlling hydrogen sulfide by nitrate dosing. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 816:151581. [PMID: 34774952 DOI: 10.1016/j.scitotenv.2021.151581] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/03/2021] [Accepted: 11/06/2021] [Indexed: 06/13/2023]
Abstract
Nitrate dosing is commonly used for controlling hydrogen sulfide in sewer systems. However, it may potentially facilitate N2O emission due to the denitrification process promoted by nitrate addition. In this study, lab-scale sewer reactors were operated to investigate the impact of nitrate addition on N2O production in sewer systems. Results showed that the N2O flux even increased by six times with the addition of nitrate when dissolved oxygen (DO) in the wastewater exceeded 0.4 mg/L. Principal component analysis showed that the N2O concentration was notably affected by DO and oxidation-reduction potential (ORP) in the wastewater. Furthermore, it was founded that N2O flux had a strong linear relationship with the DO concentration in the batch test. The microbial analysis found that the nosZ possessing organisms decreased significantly in the micro-aerobic condition and the copy numbers of nosZ gene declined consequently. It indicated that the inhibition of N2O reduced to N2 was responsible for significant accumulation and emission of N2O in the micro-aerobic condition. Given the gravity sewers are not completely anaerobic, the DO concentration is ranged from 0.1 to 2.4 mg/L in gravity sewers with the partially filled flow. Therefore, more attention should be paid to the N2O production when nitrate dosing for hydrogen sulfide controlling in gravity sewers.
Collapse
Affiliation(s)
- Guijiao Zhang
- College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058, China
| | - Yao Pang
- College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058, China
| | - Yongchao Zhou
- College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058, China.
| | - Yiping Zhang
- College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058, China
| | - David Z Zhu
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB T6G 2W2, Canada
| |
Collapse
|
8
|
Zhang Z, Chang N, Wang S, Lu J, Li K, Zheng C. Enhancing sulfide mitigation via the sustainable supply of oxygen from air-nanobubbles in gravity sewers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 808:152203. [PMID: 34890666 DOI: 10.1016/j.scitotenv.2021.152203] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/19/2021] [Accepted: 12/01/2021] [Indexed: 06/13/2023]
Abstract
Traditional air or oxygen injection is an effective and economical mitigation strategy for sulfide control in pressure sewers, but it is not suitable for gravity sewers due to the low solubility of oxygen in water under normal atmospheric conditions. Herein, an air-nanobubble (ANB) injection method was proposed for sulfide mitigation in gravity sewers, and its sulfide control efficiency was evaluated by long-term laboratory gravity sewer reactors. The results showed that an average inhibition rate of 45.36% for sulfide was obtained when ANBs were implemented, which was 3.75 times higher than that of the traditional air injection method, revealing the effectiveness and feasibility of the ANB injection method. As suggested by microbial community analysis of sewer biofilms, the relative abundance of sulfate-reducing bacteria (SRB) decreased 40.57% while that of sulfur oxidizing bacteria (SOB) increased 215.27% in the presence of ANBs, indicating that sulfide mitigation by ANB injection included both the inhibition of sulfide production and the oxidation of dissolved sulfide. The specific cost consumption of ANB injection was 1.7 $/kg-S, which was only 6.85% of that of traditional air injection (24.8 $/kg-S), suggesting that the sustainable supply of oxygen based on ANB injection is not only environmentally but also economically beneficial for sulfide mitigation. The findings of this study may provide an efficient sulfide mitigation strategy for the management of corrosion and malodour issues in the poorly ventilated gravity sewers.
Collapse
Affiliation(s)
- Zhiqiang Zhang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Na Chang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Sheping Wang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Xi'an Municipal Design and Research Institute, No.100 Zhuque Road, Xi'an 710068, People's Republic of China
| | - Jinsuo Lu
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Key Laboratory of Northwest Water Resources, Environment and Ecology, Ministry of Education, People's Republic of China; Key Laboratory of Environmental Engineering, Shaanxi Province, People's Republic of China.
| | - Kexin Li
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Cailin Zheng
- Ankang Municipal Facilities Management, House and Urban Rural Development Department of Ankang, NO.1 Bingjiang Road, Ankang 725000, Shaanxi Province, People's Republic of China
| |
Collapse
|
9
|
Rodríguez-Gómez LE, Rodríguez-Sevilla J, Hernández A, Álvarez M. Factors affecting nitrification with nitrite accumulation in treated wastewater by oxygen injection. ENVIRONMENTAL TECHNOLOGY 2021; 42:813-825. [PMID: 31314696 DOI: 10.1080/09593330.2019.1645742] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 07/14/2019] [Indexed: 06/10/2023]
Abstract
This work provides information on nitrification with nitrite accumulation in low strength ammonia (below 50 mg L-1 NH4-N) and low organic matter (below 150 mg L-1 COD) reclaimed wastewater. In the South Tenerife reclaimed wastewater pipeline (62 km long), injection of O2 has been applied to promote a nitrification process in order to improve water quality and to avoid anaerobic conditions. Nitrification occurs, in most cases, with nitrite accumulation. The amount of oxidized nitrogen compounds produced increases with the oxygen dose applied. The nitrification process is usually favoured instead of the organic matter transformation, due to the low organic matter/ammonia nitrogen ratio of water. The influence of organic matter content on nitrification has been analysed, and a good suitability for COD has been found as an indicator for nitrification limitation (for the range of COD and NH4-N concentrations of the system). Nitrification limitation has been observed above 85 mg L-1 COD, and nitrification inhibition above a concentration of 105 mg L-1. In addition, the limitation of nitrite oxidation bacteria activity (nitrite accumulation) by free ammonia and temperature has been assessed, finding that, for the range of free ammonia (0.6-2.1 mg L-1 NH3) and temperature (20.4-27.0°C) in the study, temperature plays a much more relevant role than free ammonia on nitrite accumulation. The lower limiting temperature for nitrite build-up in the system has been 21.0°C. Below this temperature, nitrite accumulation did not exist or was very low.
Collapse
Affiliation(s)
- Luis E Rodríguez-Gómez
- Departamento de Ingeniería Química y Tecnología Farmacéutica, Facultad de Ciencias, Universidad de La Laguna, La Laguna, Spain
| | - Juan Rodríguez-Sevilla
- Departamento de Ingeniería Química y Tecnología Farmacéutica, Facultad de Ciencias, Universidad de La Laguna, La Laguna, Spain
| | - Antonio Hernández
- Departamento de Ingeniería Química y Tecnología Farmacéutica, Facultad de Ciencias, Universidad de La Laguna, La Laguna, Spain
| | - Manuel Álvarez
- Departamento de Ingeniería Química y Tecnología Farmacéutica, Facultad de Ciencias, Universidad de La Laguna, La Laguna, Spain
| |
Collapse
|
10
|
Gao R, Zhang Z, Zhang T, Liu J, Lu J. Upstream Natural Pulsed Ventilation: A simple measure to control the sulfide and methane production in gravity sewer. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 742:140579. [PMID: 32629266 DOI: 10.1016/j.scitotenv.2020.140579] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/04/2020] [Accepted: 06/26/2020] [Indexed: 06/11/2023]
Abstract
Production of sulfide and methane due to anaerobic biological transformations in sewer pipes causes serious problems to sewer maintenance. For gravity sewers, enhancing ventilation is a practical method that reduces the production of both sulfide and methane. This study aimed to determine the effectiveness of a new method, Upstream Natural Pulsed Ventilation (UNPV), to control sulfide and methane production in gravity sewers. Two lab-scale reactors simulating the gravity sewer pipe with and without ventilation were set up to assess the effectiveness. The results show that compared with the gravity sewer pipe without ventilation, under the UNPV condition, the total sulfide concentration reduced by 39.08% and 58.74%, and the methane concentration reduced by 42.29% and 35.70% in the upstream and downstream sewer pipe, respectively. High-throughput sequencing analysis showed that the UNPV method could inhibit the proliferation of sulfate-reducing bacteria and stimulate the proliferation of sulfur-oxidizing bacteria within the whole sewer pipe. The composition of methanogenic archaea that are responsible for methane production was changed by ventilation. The increased oxidation-reduction potential and organic carbon transportation in wastewater under ventilation may be responsible for the microbial community changes. The findings of this study may provide new insight to reduce sulfide and methane production in gravity sewers.
Collapse
Affiliation(s)
- Ruyue Gao
- Environmental and Municipal Engineering Department, Xi'an University of Architecture and Technology, Xi'an, Shaanxi, PR China
| | - Zhiqiang Zhang
- Environmental and Municipal Engineering Department, Xi'an University of Architecture and Technology, Xi'an, Shaanxi, PR China
| | - Tingwei Zhang
- Environmental and Municipal Engineering Department, Xi'an University of Architecture and Technology, Xi'an, Shaanxi, PR China
| | - Junzhuo Liu
- Environmental and Municipal Engineering Department, Xi'an University of Architecture and Technology, Xi'an, Shaanxi, PR China
| | - Jinsuo Lu
- Environmental and Municipal Engineering Department, Xi'an University of Architecture and Technology, Xi'an, Shaanxi, PR China; Key Laboratory of Northwest Water Resources, Environment and Ecology, Ministry of Education, PR China; Key Laboratory of Environmental Engineering, Shaanxi Province, PR China.
| |
Collapse
|
11
|
Shi X, Gao G, Tian J, Wang XC, Jin X, Jin P. Symbiosis of sulfate-reducing bacteria and methanogenic archaea in sewer systems. ENVIRONMENT INTERNATIONAL 2020; 143:105923. [PMID: 32634668 DOI: 10.1016/j.envint.2020.105923] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/20/2020] [Accepted: 06/20/2020] [Indexed: 06/11/2023]
Abstract
Sulfide and methane emissions always simultaneously exist in natural environment and constitute a major topic of societal concern. However, the metabolic environments between sulfate-reducing bacteria (SRB) and methanogenic archaea (MA) exist a great difference, which seems to be opposite to the coexisting phenomenon. To explore this issue, the comprehensive biofilm structures, substrate consuming and metabolism pathways of SRB and MA were investigated in a case study of urban sewers. The results showed that, due to the stricter environmental requirements of MA than SRB, SRB became the preponderant microorganism which promoted the rapid generation of sulfide in the initial period of biofilm formation. According to a metagenomic analysis, the SRB appeared to be more preferential than MA in sewers, and the preponderant SRB could provide a key medium (Methyl-coenzyme M) for methane metabolism. Therefore, the diversity of MA gradually increased, and the symbiosis system formed preliminarily. In addition, via L-cysteine, methane metabolism also participated in sulfide consumption which was involved in cysteine and methionine metabolism. This phenomenon of sulfide consumption led to the forward reaction of sulfide metabolism, which could promote sulfide generation while stabilizing the pH value (H+ concentration) and S2- concentrations which should have inhibited SRB and MA production. Therefore, the heavily intertwined interactions between sulfide and methane metabolism provided environmental security for SRB and MA, and completely formed the symbiosis between SRB and MA. Based on these findings, an ecological model involving synergistic mechanism between sulfide and methane generation is proposed and this model can also improve understanding on the symbiosis of SRB and MA in the natural environment.
Collapse
Affiliation(s)
- Xuan Shi
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China
| | - Ge Gao
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China
| | - Jiameng Tian
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China
| | - Xiaochang C Wang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China; Northwest China Key Laboratory of Water Resources and Environment Ecology, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China
| | - Xin Jin
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China
| | - Pengkang Jin
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China; Northwest China Key Laboratory of Water Resources and Environment Ecology, Xi'an University of Architecture and Technology, Xi'an, Shaanxi Province 710055, China.
| |
Collapse
|
12
|
Li W, Zheng T, Ma Y, Liu J. Current status and future prospects of sewer biofilms: Their structure, influencing factors, and substance transformations. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 695:133815. [PMID: 31416035 DOI: 10.1016/j.scitotenv.2019.133815] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 08/01/2019] [Accepted: 08/06/2019] [Indexed: 06/10/2023]
Abstract
With rapid urbanization, sewer systems are extensively being constructed for the collection and transportation of sewage to minimize the severe environmental and health issues, especially relating to the spread diseases. The existence of abundant biofilms on the inner walls of sewers could lead to potential risks such as sewer explosions, poisonous gas leaks, and pipe corrosions with the transformations of various kinds of pollutants. Therefore, it is urgent to clarify their inner mechanisms to safely govern sewer systems. In this study, the characteristics of sewer biofilms including their structure, influencing factors, and substance transformations were analyzed in-depth. The results reveal that sewer biofilms (1.0 mm depth approximately) consist of large quantities of inorganic and some organic substances, while the abundant functional genus of the bacteria and archaea are summarized. Sewer biofilms influencing factors were determined to be sewer operation mode, sewage characteristics, and shear stress. Further, the transformation of organics, sulfur, and nitrogen as well as emerging micropollutants (such as, biomarkers, antibiotic resistance genes, and engineered nanoparticles) was investigated to guarantee sewer security and public health. Therefore, the current review could be considered as guidance for researchers and decision-makers.
Collapse
Affiliation(s)
- Wenkai Li
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085, China; University of Chinese Academy of Sciences, 19 (A) Yuquan Road, Shijingshan District, Beijing 100049, China.
| | - Tianlong Zheng
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085, China; University of Chinese Academy of Sciences, 19 (A) Yuquan Road, Shijingshan District, Beijing 100049, China.
| | - Yingqun Ma
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore.
| | - Junxin Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085, China; University of Chinese Academy of Sciences, 19 (A) Yuquan Road, Shijingshan District, Beijing 100049, China.
| |
Collapse
|
13
|
Xu J, He Q, Li H, Yang C, Wang Y, Ai H. Modeling of methane formation in gravity sewer system: the impact of microorganism and hydraulic condition. AMB Express 2018. [PMID: 29516233 PMCID: PMC5842170 DOI: 10.1186/s13568-018-0559-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Sewer system is an important source of methane formation and emission. Although some models were developed to predict methane production in sewers, the impact of microorganism amount was indicated indirectly. Here, seven laboratory scale sewers with varied wall-shear stresses were established. The biofilm thickness, microorganism amount, DO distribution, microorganism community in the biofilms and methane production in the sewers were measured. Based on experimental data, an empirical model was developed to directly describe the relationship between methane production, microorganism amount and wall-shear stress. The results showed that DO concentration decreased significantly along the biofilm depth under varied wall-shear stress, and the DO reduction rate was positively related to the intensity of wall-shear stress. The dominant archaea species in mature biofilms were similar whereas the proportions showed remarkable differences. The abundance of Methanospirillum in biofilms cultured at 2.0 Pa wall-shear stress was 53.08% more than that at 1.29 Pa. The maximum methane production rate, 2.04 mg/L wastewater day, was obtained when the wall-shear stress kept at 1.45 Pa, which was 1.2-fold higher than the minimum in sewer at 0.5 Pa. The R2 value of the established model was 0.95, the difference between the measurement and simulation was in the rage of 1.5–13.0%.
Collapse
|
14
|
Lin HW, Lu Y, Ganigué R, Sharma KR, Rabaey K, Yuan Z, Pikaar I. Simultaneous use of caustic and oxygen for efficient sulfide control in sewers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 601-602:776-783. [PMID: 28578235 DOI: 10.1016/j.scitotenv.2017.05.225] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 05/23/2017] [Accepted: 05/24/2017] [Indexed: 06/07/2023]
Abstract
Periodic caustic shock-loading is a commonly used method for sulfide control in sewers. Caustic shock-loading relies on the elevation of the sewage pH to ≥10.5 for several hours, thereby removing sewer pipe biofilms as well as deactivating SRB activity in the remaining biofilm. Although a widely used method, SRB activity is often not completely inhibited, and as such sulfide is still being generated. Here, we propose and experimentally demonstrate an innovative approach which combines caustic with oxygen, another commonly used method, as a dosing strategy for overcoming the drawbacks of caustic shock-loading. Six laboratory-scale rising main reactors were subjected to three dosing schemes over a period of three months, namely (i) simultaneous caustic and oxygen addition, (ii) caustic addition and (iii) no chemical addition. Our results showed that the combination of caustic and oxygen achieved efficient sulfide control, leading to a prolonged biofilm recovery period in between caustic shocks. In addition, methane emissions were reduced to a negligible level compared to caustic treatment only. To translate the findings to real-life application, the key parameters obtained during the long-term lab-scale experiments were subjected to extensive simulation studies using the SeweX model under a wide range of conditions commonly found in sewers. Overall, this study highlights the potential of periodic shock-loading and intermittent oxygen injection as combined dosing strategy for efficient sulfide control in sewers.
Collapse
Affiliation(s)
- Hui-Wen Lin
- The University of Queensland, Advanced Water Management Centre (AWMC), QLD 4072, Australia
| | - Yang Lu
- The University of Queensland, Advanced Water Management Centre (AWMC), QLD 4072, Australia
| | - Ramon Ganigué
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Keshab R Sharma
- The University of Queensland, Advanced Water Management Centre (AWMC), QLD 4072, Australia
| | - Korneel Rabaey
- The University of Queensland, Advanced Water Management Centre (AWMC), QLD 4072, Australia; Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Zhiguo Yuan
- The University of Queensland, Advanced Water Management Centre (AWMC), QLD 4072, Australia
| | - Ilje Pikaar
- The University of Queensland, Advanced Water Management Centre (AWMC), QLD 4072, Australia; The University of Queensland, The School of Civil Engineering, QLD 4072, Australia.
| |
Collapse
|
15
|
Liu Y, Ni BJ, Sharma KR, Yuan Z. Methane emission from sewers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 524-525:40-51. [PMID: 25889543 DOI: 10.1016/j.scitotenv.2015.04.029] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 04/03/2015] [Accepted: 04/03/2015] [Indexed: 05/12/2023]
Abstract
Recent studies have shown that sewer systems produce and emit a significant amount of methane. Methanogens produce methane under anaerobic conditions in sewer biofilms and sediments, and the stratification of methanogens and sulfate-reducing bacteria may explain the simultaneous production of methane and sulfide in sewers. No significant methane sinks or methanotrophic activities have been identified in sewers to date. Therefore, most of the methane would be emitted at the interface between sewage and atmosphere in gravity sewers, pumping stations, and inlets of wastewater treatment plants, although oxidation of methane in the aeration basin of a wastewater treatment plant has been reported recently. Online measurements have also revealed highly dynamic temporal and spatial variations in methane production caused by factors such as hydraulic retention time, area-to-volume ratio, temperature, and concentration of organic matter in sewage. Both mechanistic and empirical models have been proposed to predict methane production in sewers. Due to the sensitivity of methanogens to environmental conditions, most of the chemicals effective in controlling sulfide in sewers also suppress or diminish methane production. In this paper, we review the recent studies on methane emission from sewers, including the production mechanisms, quantification, modeling, and mitigation.
Collapse
Affiliation(s)
- Yiwen Liu
- Advanced Water Management Centre, The University of Queensland, QLD, Australia
| | - Bing-Jie Ni
- Advanced Water Management Centre, The University of Queensland, QLD, Australia
| | - Keshab R Sharma
- Advanced Water Management Centre, The University of Queensland, QLD, Australia
| | - Zhiguo Yuan
- Advanced Water Management Centre, The University of Queensland, QLD, Australia.
| |
Collapse
|
16
|
Liu Y, Sharma KR, Ni BJ, Fan L, Murthy S, Tyson GQ, Yuan Z. Effects of nitrate dosing on sulfidogenic and methanogenic activities in sewer sediment. WATER RESEARCH 2015; 74:155-165. [PMID: 25727155 DOI: 10.1016/j.watres.2015.02.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 02/05/2015] [Accepted: 02/06/2015] [Indexed: 06/04/2023]
Abstract
Nitrate dosing is widely used to control sulfide and methane formation in sewers. The impact of nitrate on sulfide and methane production by sewer biofilms in rising mains has been elucidated recently. However, little is known about the effect of nitrate on biologically active sewer sediment, which is substantially thicker than rising main biofilms (centimeters vs. hundreds of micrometers, respectively). In this study, we investigated the effect of nitrate addition to sewer sediment cultivated in lab-scale sewer sediment reactors. Batch test results showed that nitrate addition does not suppress sulfide production in sewer sediment, but it reduces sulfide accumulation through anoxic sulfide oxidation in the sediment and hence, also reduces sulfide accumulation in the bulk water. Microsensor measurement of sediment sulfide revealed the presence of sulfide oxidation and sulfide production zones with the interface dynamically regulated by the depth of nitrate penetration. In contrast, the methane production activity of sewer sediment was substantially reduced, likely due to the long-term inhibitory effects of nitrate on methanogens. Pore water measurements showed that methane production activity in the sediment zone with frequent nitrate exposure was completely suppressed, and consequently, the methane production zone re-established deeper in the sediment where nitrate penetration was infrequent.
Collapse
Affiliation(s)
- Yiwen Liu
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Keshab R Sharma
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Bing-Jie Ni
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Lu Fan
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Sudhir Murthy
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia; District of Columbia Water and Sewer Authority, Washington, DC 20032, USA
| | - Gene Q Tyson
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia; Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Zhiguo Yuan
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia.
| |
Collapse
|
17
|
Sun J, Hu S, Sharma KR, Ni BJ, Yuan Z. Degradation of methanethiol in anaerobic sewers and its correlation with methanogenic activities. WATER RESEARCH 2015; 69:80-89. [PMID: 25437340 DOI: 10.1016/j.watres.2014.11.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 11/04/2014] [Accepted: 11/05/2014] [Indexed: 05/07/2023]
Abstract
Methanethiol (MT) is considered one of the predominant odorants in sewer systems. Therefore, understanding MT transformation in sewers is essential to sewer odor assessment and abatement. In this study, we investigated the degradation of MT in laboratory anaerobic sewers. Experiments were carried out in seven anaerobic sewer reactors with biofilms at different stages of development. MT degradation was found to be strongly dependent on the methanogenic activity of sewer biofilms. The MT degradation rate accelerated with the increase of methanogenic activity of sewer biofilms, resulting in MT accumulation (i.e. net production) in sewer reactors with relatively low methanogenic activities, and MT removal in reactors with higher methanogenic activities. A Monod-type kinetic expression was developed to describe MT degradation kinetics in anaerobic sewers, in which the maximum degradation rate was modeled as a function of the maximum methane production rate through a power function. It was also found that MT concentration had a linear relationship with acetate concentration, which may be used for preliminary assessment of MT presence in anaerobic sewers.
Collapse
Affiliation(s)
- Jing Sun
- Advanced Water Management Centre, The University of Queensland, St. Lucia 4072, Queensland, Australia
| | - Shihu Hu
- Advanced Water Management Centre, The University of Queensland, St. Lucia 4072, Queensland, Australia
| | - Keshab Raj Sharma
- Advanced Water Management Centre, The University of Queensland, St. Lucia 4072, Queensland, Australia
| | - Bing-Jie Ni
- Advanced Water Management Centre, The University of Queensland, St. Lucia 4072, Queensland, Australia
| | - Zhiguo Yuan
- Advanced Water Management Centre, The University of Queensland, St. Lucia 4072, Queensland, Australia.
| |
Collapse
|
18
|
Stratified microbial structure and activity in sulfide- and methane-producing anaerobic sewer biofilms. Appl Environ Microbiol 2014; 80:7042-52. [PMID: 25192994 DOI: 10.1128/aem.02146-14] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Simultaneous production of sulfide and methane by anaerobic sewer biofilms has recently been observed, suggesting that sulfate-reducing bacteria (SRB) and methanogenic archaea (MA), microorganisms known to compete for the same substrates, can coexist in this environment. This study investigated the community structures and activities of SRB and MA in anaerobic sewer biofilms (average thickness of 800 μm) using a combination of microelectrode measurements, molecular techniques, and mathematical modeling. It was seen that sulfide was mainly produced in the outer layer of the biofilm, between the depths of 0 and 300 μm, which is in good agreement with the distribution of SRB population as revealed by cryosection-fluorescence in situ hybridization (FISH). SRB had a higher relative abundance of 20% on the surface layer, which decreased gradually to below 3% at a depth of 400 μm. In contrast, MA mainly inhabited the inner layer of the biofilm. Their relative abundances increased from 10% to 75% at depths of 200 μm and 700 μm, respectively, from the biofilm surface layer. High-throughput pyrosequencing of 16S rRNA amplicons showed that SRB in the biofilm were mainly affiliated with five genera, Desulfobulbus, Desulfomicrobium, Desulfovibrio, Desulfatiferula, and Desulforegula, while about 90% of the MA population belonged to the genus Methanosaeta. The spatial organizations of SRB and MA revealed by pyrosequencing were consistent with the FISH results. A biofilm model was constructed to simulate the SRB and MA distributions in the anaerobic sewer biofilm. The good fit between model predictions and the experimental data indicate that the coexistence and spatial structure of SRB and MA in the biofilm resulted from the microbial types and their metabolic transformations and interactions with substrates.
Collapse
|