1
|
Wu H, Li A, Gao S, Xing Z, Zhao P. The performance, mechanism and greenhouse gas emission potential of nitrogen removal technology for low carbon source wastewater. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 903:166491. [PMID: 37633391 DOI: 10.1016/j.scitotenv.2023.166491] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 07/24/2023] [Accepted: 08/20/2023] [Indexed: 08/28/2023]
Abstract
Excessive nitrogen can lead to eutrophication of water bodies. However, the removal of nitrogen from low carbon source wastewater has always been challenging due to the limited availability of carbon sources as electron donors. Biological nitrogen removal technology can be classified into three categories: heterotrophic biological technology (HBT) that utilizes organic matter as electron donors, autotrophic biological technology (ABT) that relies on inorganic electrons as electron donors, and heterotrophic-autotrophic coupling technology (CBT) that combines multiple electron donors. This work reviews the research progress, microbial mechanism, greenhouse gas emission potential, and challenges of the three technologies. In summary, compared to HBT and ABT, CBT shows greater application potential, although pilot-scale implementation is yet to be achieved. The composition of nitrogen removal microorganisms is different, mainly driven by electron donors. ABT and CBT exhibit the lowest potential for greenhouse gas emissions compared to HBT. N2O, CH4, and CO2 emissions can be controlled by optimizing conditions and adding constructed wetlands. Furthermore, these technologies need further improvement to meet increasingly stringent emission standards and address emerging pollutants. Common measures include bioaugmentation in HBT, the development of novel materials to promote mass transfer efficiency of ABT, and the construction of BES-enhanced multi-electron donor systems to achieve pollutant prevention and removal. This work serves as a valuable reference for the development of clean and sustainable low carbon source wastewater treatment technology, as well as for addressing the challenges posed by global warming.
Collapse
Affiliation(s)
- Heng Wu
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
| | - Anjie Li
- College of Grassland Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Sicong Gao
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Zhilin Xing
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, PR China.
| | - Piao Zhao
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China.
| |
Collapse
|
2
|
Huang L, Xiong H, Jiang C, He J, Lyu W, Chen Y. Pathways and biological mechanisms of N 2O emission reduction by adding biochar in the constructed wetland based on 15N stable isotope tracing. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 342:118359. [PMID: 37311348 DOI: 10.1016/j.jenvman.2023.118359] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 05/31/2023] [Accepted: 06/07/2023] [Indexed: 06/15/2023]
Abstract
Constructed wetlands (CWs) added with biochar were built to study pollutant removal efficiencies, nitrous oxide (N2O) emission characteristics, and biological mechanisms in nitrogen transformation. The results showed that biochar addition enhanced the average removal rates of ammonium (NH4+-N), total nitrogen, and chemical oxygen demand by 4.03-18.5%, 2.90-4.99%, and 2.87-5.20% respectively while reducing N2O emissions by 25.85-83.41%. Based on 15N stable isotope tracing, it was found that nitrification, denitrification, and simultaneous nitrification and denitrification were the main processes contributing to N2O emission. The addition of biochar resulted in maximum reduction rates of 71.50%, 80.66%, and 73.09% for these three processes, respectively. The relative abundance of nitrogen-transforming microbes, such as Nitrospira, Dechloromonas, and Denitratisoma, increased after the addition of biochar, promoting nitrogen removal and reducing N2O emissions. Adding biochar could increase the functional gene copy number and enzyme activity responsible for nitrogen conversion, which helped achieve efficient NH4+-N oxidation and eliminate nitrite accumulation, thereby reducing N2O emissions.
Collapse
Affiliation(s)
- Lei Huang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, 400715, PR China; Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, PR China; Chongqing Engineering Research Center of Rural Cleaner Production, Chongqing, 400716, PR China.
| | - Haifeng Xiong
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, 400715, PR China; Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, PR China
| | - Chunli Jiang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, 400715, PR China; Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, PR China
| | - Jinke He
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, 400715, PR China; Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, PR China
| | - Wanlin Lyu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, 400715, PR China; Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, PR China
| | - Yucheng Chen
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment (Ministry of Education), College of Resources and Environment, Southwest University, Chongqing, 400715, PR China; Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing, 400716, PR China; Chongqing Engineering Research Center of Rural Cleaner Production, Chongqing, 400716, PR China
| |
Collapse
|
3
|
Lu H, Wang H, Wu Q, Luo H, Zhao Q, Liu B, Si Q, Zheng S, Guo W, Ren N. Automatic control and optimal operation for greenhouse gas mitigation in sustainable wastewater treatment plants: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 855:158849. [PMID: 36122730 DOI: 10.1016/j.scitotenv.2022.158849] [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: 06/30/2022] [Revised: 09/01/2022] [Accepted: 09/14/2022] [Indexed: 06/15/2023]
Abstract
In order to promote low-carbon sustainable operational management of the wastewater treatment plants (WWTPs), automatic control and optimal operation technologies, which devote to improving effluent quality, operational costs and greenhouse gas (GHG) emissions, have flourished in recent years. There is no consensus on the design procedure for optimal control/operation of sustainable WWTPs. In this review, we summarize recent researches on developing control and optimization strategies for GHG mitigation in WWTPs. Faced with the fact that direct carbon dioxide (CO2) emissions (considered biological origin) are generally not included in the carbon footprint of WWTPs, direct emissions (nitrous oxide (N2O), methane (CH4)) and indirect emissions are paid much attention. Firstly, the plant-wide models with GHG dynamic simulation, which are employed to design and evaluate the automatic control schemes as well as representative studies on identifying key factors affecting GHG emissions or comprehensive performance are outlined. Then, both traditional and advanced control methods commonly used in GHG mitigation are reviewed in detail, followed by the multi-objective optimization practices of control/operational parameters. Based on the mentioned control and (or) optimization strategies, a novel design framework for the optimal control/operation of sustainable WWTPs is proposed. The findings and design framework proposed in the paper will provide guidance for GHG mitigation and sustainable operation in WWTPs. It is foreseeable that more accurate and appropriate plant-wide models together with flexible control methods and intelligent optimization strategies will be developed to satisfy the upgrading requirements of WWTPs in the future.
Collapse
Affiliation(s)
- Hao Lu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Huazhe Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Qinglian Wu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Haichao Luo
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Qi Zhao
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Banghai Liu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Qishi Si
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Shanshan Zheng
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Wanqian Guo
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Nanqi Ren
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| |
Collapse
|
4
|
Lv YT, Chen X, Zhang X, Zhu C, Pan Y, Sun T, Wang L. Denitrification for acidic wastewater treatment: Long-term performance, microbial communities, and nitrous oxide emissions. J Biosci Bioeng 2022; 134:513-520. [PMID: 36216689 DOI: 10.1016/j.jbiosc.2022.09.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 09/15/2022] [Accepted: 09/16/2022] [Indexed: 11/13/2022]
Abstract
Acidic nitrogenous wastewater often requires alkali pretreatment before biological treatment, which results in increased system complexity and operating costs. The demonstration of denitrification under acidic conditions would provide a theoretical basis for the direct treatment of such wastewater. In this study, the denitrification performance, microbial community, and nitrous oxide (N2O) emissions under acidic conditions were investigated using a sequencing batch reactor. When the influent pH decreased from 5.5 to 4.5, the sequencing batch reactor removed 99.8 ± 0.2% of the nitrate and 92.5 ± 1.6% (n = 171) of the chemical oxygen demand, and the production efficiency of N2O increased significantly to 11.45%. This was 2.6-fold higher than that observed at pH 5.5. The long-term denitrification treatment of acidic wastewater (pH 4.5) led to the formation of granular sludge, and Thauera, Allorhizobium-Neorhizobium-Parararhizobium-Rhizobium, and Diaphorobacter became the dominant microbes with a collective abundance of 81.3%. More importantly, only 0.25% of the nitrate was denitrified as N2O, and the batch test revealed that the emissions of N2O decreased with the increase in sludge size. These results indicate that denitrifying granular sludge formed under acidic conditions and denitrifying bacteria capable of N2O reduction proliferated, which both resulted in a significant reduction in the release of N2O.
Collapse
Affiliation(s)
- Yong-Tao Lv
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Xi'an 710055, China; Key Laboratory of Membrane Separation of Shaanxi Province, Research Institute of Membrane Separation Technology of Shaanxi Province, No. 13 Yanta Road, Xi'an 710055, China; Key Laboratory of Environmental Engineering of Shaanxi Province, No. 13 Yanta Road, Xi'an 710055, China.
| | - Xiaolin Chen
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Xi'an 710055, China; Key Laboratory of Membrane Separation of Shaanxi Province, Research Institute of Membrane Separation Technology of Shaanxi Province, No. 13 Yanta Road, Xi'an 710055, China; Key Laboratory of Environmental Engineering of Shaanxi Province, No. 13 Yanta Road, Xi'an 710055, China
| | - Xuyang Zhang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Xi'an 710055, China; Key Laboratory of Membrane Separation of Shaanxi Province, Research Institute of Membrane Separation Technology of Shaanxi Province, No. 13 Yanta Road, Xi'an 710055, China; Key Laboratory of Environmental Engineering of Shaanxi Province, No. 13 Yanta Road, Xi'an 710055, China
| | - Chuanshou Zhu
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Xi'an 710055, China; Key Laboratory of Membrane Separation of Shaanxi Province, Research Institute of Membrane Separation Technology of Shaanxi Province, No. 13 Yanta Road, Xi'an 710055, China; Key Laboratory of Environmental Engineering of Shaanxi Province, No. 13 Yanta Road, Xi'an 710055, China
| | - Yongbao Pan
- Shaanxi Modern Architecture Design & Research Institute Co. Ltd., No. 168 Xingtai 7th street, Xi'an 710021, China
| | - Ting Sun
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Xi'an 710055, China; Key Laboratory of Membrane Separation of Shaanxi Province, Research Institute of Membrane Separation Technology of Shaanxi Province, No. 13 Yanta Road, Xi'an 710055, China; Key Laboratory of Environmental Engineering of Shaanxi Province, No. 13 Yanta Road, Xi'an 710055, China
| | - Lei Wang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Xi'an 710055, China; Key Laboratory of Membrane Separation of Shaanxi Province, Research Institute of Membrane Separation Technology of Shaanxi Province, No. 13 Yanta Road, Xi'an 710055, China; Key Laboratory of Environmental Engineering of Shaanxi Province, No. 13 Yanta Road, Xi'an 710055, China
| |
Collapse
|
5
|
Gruber W, Magyar PM, Mitrovic I, Zeyer K, Vogel M, von Känel L, Biolley L, Werner RA, Morgenroth E, Lehmann MF, Braun D, Joss A, Mohn J. Tracing N 2O formation in full-scale wastewater treatment with natural abundance isotopes indicates control by organic substrate and process settings. WATER RESEARCH X 2022; 15:100130. [PMID: 35287381 PMCID: PMC8917317 DOI: 10.1016/j.wroa.2022.100130] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/25/2022] [Accepted: 02/26/2022] [Indexed: 06/14/2023]
Abstract
Nitrous oxide (N2O) dominates greenhouse gas emissions in wastewater treatment plants (WWTPs). Formation of N2O occurs during biological nitrogen removal, involves multiple microbial pathways, and is typically very dynamic. Consequently, N2O mitigation strategies require an improved understanding of nitrogen transformation pathways and their modulating controls. Analyses of the nitrogen (N) and oxygen (O) isotopic composition of N2O and its substrates at natural abundance have been shown to provide valuable information on formation and reduction pathways in laboratory settings, but have rarely been applied to full-scale WWTPs. Here we show that N-species isotope ratio measurements at natural abundance level, combined with long-term N2O monitoring, allow identification of the N2O production pathways in a full-scale plug-flow WWTP (Hofen, Switzerland). Heterotrophic denitrification appears as the main N2O production pathway under all tested process conditions (0-2 mgO2/l, high and low loading conditions), while nitrifier denitrification was less important, and more variable. N2O production by hydroxylamine oxidation was not observed. Fractional N2O elimination by reduction to dinitrogen (N2) during anoxic conditions was clearly indicated by a concomitant increase in site preference, δ18O(N2O) and δ15N(N2O). N2O reduction increased with decreasing availability of dissolved inorganic N and organic substrates, which represents the link between diurnal N2O emission dynamics and organic substrate fluctuations. Consequently, dosing ammonium-rich reject water under low-organic-substrate conditions is unfavorable, as it is very likely to cause high net N2O emissions. Our results demonstrate that monitoring of the N2O isotopic composition holds a high potential to disentangle N2O formation mechanisms in engineered systems, such as full-scale WWTP. Our study serves as a starting point for advanced campaigns in the future combining isotopic technologies in WWTP with complementary approaches, such as mathematical modeling of N2O formation or microbial assays to develop efficient N2O mitigation strategies.
Collapse
Affiliation(s)
- Wenzel Gruber
- Eawag, Swiss Federal Institute for Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| | - Paul M Magyar
- Department of Environmental Sciences, Aquatic and Isotope Biogeochemistry, University of Basel, Basel 4056, Switzerland
| | - Ivan Mitrovic
- Eawag, Swiss Federal Institute for Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| | - Kerstin Zeyer
- Laboratory for Air Pollution / Environmental Technology, Empa, Dübendorf 8600, Switzerland
| | - Michael Vogel
- Department of Civil, Environmental and Geomatic Engineering, ETH, Zürich 8093, Switzerland
| | - Luzia von Känel
- Department of Civil, Environmental and Geomatic Engineering, ETH, Zürich 8093, Switzerland
| | - Lucien Biolley
- Department of Civil, Environmental and Geomatic Engineering, ETH, Zürich 8093, Switzerland
| | - Roland A Werner
- Department of Environmental Systems Science, ETH, Zürich 8092, Switzerland
| | - Eberhard Morgenroth
- Eawag, Swiss Federal Institute for Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| | - Moritz F Lehmann
- Department of Environmental Sciences, Aquatic and Isotope Biogeochemistry, University of Basel, Basel 4056, Switzerland
| | - Daniel Braun
- Department of Civil, Environmental and Geomatic Engineering, ETH, Zürich 8093, Switzerland
| | - Adriano Joss
- Eawag, Swiss Federal Institute for Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| | - Joachim Mohn
- Laboratory for Air Pollution / Environmental Technology, Empa, Dübendorf 8600, Switzerland
| |
Collapse
|
6
|
Wang S, Yu H, Su Q, Zuo J. Exploring the role of heterotrophs in partial nitritation-anammox process treating thermal hydrolysis process - anaerobic digestion reject water. BIORESOURCE TECHNOLOGY 2021; 341:125762. [PMID: 34450441 DOI: 10.1016/j.biortech.2021.125762] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/07/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
Heterotrophic bacteria (HB) are generally prevalent in anammox-based processes, but their functional and ecological roles in partial nitritation-anammox (PN/A) process treating high-organics wastewater remained unclear. This study aimed to elucidate HB activities and microbial interactions in a one-stage PN/A treating thermal hydrolysis process (THP) - anaerobic digestion (AD) reject water. The PN/A reactor achieved a satisfactory nitrogen removal rate of 0.58 ± 0.06 g N/(L·d), and around 12% of COD in the THP-AD reject water was removed. N2O emission factors of the PN/A reactor were 1.15% ± 0.18% treating synthetic wastewater, and 0.95% ± 0.06% treating reject water. A balanced symbiotic relationship was maintained between HB and functional groups (i.e., anammox bacteria and aerobic-ammonia-oxidizing bacteria) over the reactor operation. The relative abundances of Anaerolineae spp. clearly increased, while Denitratisoma, capable of denitrification, slightly decreased when treating THP-AD reject water. The preference for electron donors of heterotrophs explained discrepant growth trends.
Collapse
Affiliation(s)
- Sike Wang
- Department of Material and Environmental Engineering, Shenzhen Polytechnic, Shenzhen 518055, China; State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Heng Yu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; College of Chemistry and Chemical Engineering, Xi'an Shiyou University, Xi'an, Shaanxi Province 710065, China
| | - Qingxian Su
- Department of Environmental Engineering, Technical University of Denmark, Kgs., Lyngby 2800, Denmark
| | - Jiane Zuo
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.
| |
Collapse
|
7
|
Duan H, Zhao Y, Koch K, Wells GF, Zheng M, Yuan Z, Ye L. Insights into Nitrous Oxide Mitigation Strategies in Wastewater Treatment and Challenges for Wider Implementation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:7208-7224. [PMID: 33975433 DOI: 10.1021/acs.est.1c00840] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Nitrous oxide (N2O) emissions account for the majority of the carbon footprint of wastewater treatment plants (WWTPs). Many N2O mitigation strategies have since been developed while a holistic view is still missing. This article reviews the state-of-the-art of N2O mitigation studies in wastewater treatment. Through analyzing existing studies, this article presents the essential knowledge to guide N2O mitigations, and the logics behind mitigation strategies. In practice, mitigations are mainly carried out by aeration control, feed scheme optimization, and process optimization. Despite increasingly more studies, real implementation remains rare, which is a combined result of unclear climate change policies/incentives, as well as technical challenges. Five critical technical challenges, as well as opportunities, of N2O mitigations were identified. It is proposed that (i) quantification methods for overall N2O emissions and pathway contributions need improvement; (ii) a reliable while straightforward mathematical model is required to quantify benefits and compare mitigation strategies; (iii) tailored risk assessment needs to be conducted for WWTPs, in which more long-term full-scale trials of N2O mitigation are urgently needed to enable robust assessments of the resulting operational costs and impact on nutrient removal performance; (iv) current mitigation strategies focus on centralized WWTPs, more investigations are warranted for decentralised systems, especially decentralized activated sludge WWTPs; and (v) N2O may be mitigated by adopting novel strategies promoting N2O reduction denitrification or microorganisms that emit less N2O. Overall, we conclude N2O mitigation research is reaching a maturity while challenges still exist for a wider implementation, especially in relation to the reliability of N2O mitigation strategies and potential risks to nutrient removal performances of WWTPs.
Collapse
Affiliation(s)
- Haoran Duan
- School of Chemical Engineering, the University of Queensland, St. Lucia, Queensland 4072, Australia
- Advanced Water Management Centre (AWMC), the University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Yingfen Zhao
- School of Chemical Engineering, the University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Konrad Koch
- Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, 85748 Garching, Germany
| | - George F Wells
- Department of Civil and Environmental Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Min Zheng
- Advanced Water Management Centre (AWMC), the University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Zhiguo Yuan
- Advanced Water Management Centre (AWMC), the University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Liu Ye
- School of Chemical Engineering, the University of Queensland, St. Lucia, Queensland 4072, Australia
| |
Collapse
|
8
|
Chen H, Du M, Wang D, Zhou Y, Zeng L, Yang X. Influence of chlortetracycline as an antibiotic residue on nitrous oxide emissions from wastewater treatment. BIORESOURCE TECHNOLOGY 2020; 313:123696. [PMID: 32570074 DOI: 10.1016/j.biortech.2020.123696] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/10/2020] [Accepted: 06/13/2020] [Indexed: 06/11/2023]
Abstract
Strengthening the removal of antibiotics in wastewater treatment plants is a research focus, but whether antibiotics affect nitrous oxide (N2O) emissions from wastewater treatment remains to be determined. In this study, the effect of chlortetracycline (CTC) on N2O emissions in anaerobic/oxic/anoxic sequential batch reactors was investigated. Experimental results show that CTC promotes N2O emissions during biological nutrient removal. The addition of 0.1 mg/L CTC increased the N2O emission factor by 41.4% compared to the control. Mechanism exploration shows that CTC stimulates the release of extracellular polymeric substance (EPS) and binds to it, the generated EPS-CTC conjugates hinder or expand the mass transfer channel, which intensifies the electronic competition between oxidoreductases and the substrate competition between microorganisms, resulting in incomplete denitrification and nitrite accumulation, thereby increasing N2O emissions.
Collapse
Affiliation(s)
- Hongbo Chen
- College of Environment and Resources, Xiangtan University, Xiangtan 411105, China.
| | - Mingyang Du
- College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Dongbo Wang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
| | - Yaoyu Zhou
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong, China
| | - Long Zeng
- College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Xiao Yang
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| |
Collapse
|
9
|
Wang H, Sun Y, Wu G, Guan Y. Effect of anoxic to aerobic duration ratios on nitrogen removal and nitrous oxide emission in the multiple anoxic/aerobic process. ENVIRONMENTAL TECHNOLOGY 2019; 40:1676-1685. [PMID: 29333979 DOI: 10.1080/09593330.2018.1427801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 01/09/2018] [Indexed: 06/07/2023]
Abstract
Characteristics of nitrogen removal and nitrous oxide (N2O) emission in the multiple anoxic/aerobic (AO) process were examined in three sequencing batch reactors (SBRs) with different anoxic durations (50 min, SBRH; 40 min, SBRM; 30 min, SBRL) and a fixed aerobic duration of 30 min. The highest total inorganic nitrogen removal percentage of 85.8% was obtained in SBRH, while a minimum N2O emission factor of 1.9% was obtained in SBRL. During nitrification batch experiments, the N2O emission factor and emission rate were both lower in SBRH than SBRL. More N2O production was obtained during denitrification in SBRH when denitrifiers utilized intracellular organic carbon. Nitrite reduction by heterotrophs was the main N2O production pathway during simultaneous nitrification and denitrification in SBRH and SBRL, with the N2O emission factor of 31.3% and 36.3%, respectively. Adequate anoxic duration and lowering aerobic nitrite concentrations could be adopted to mitigate N2O emission in the multiple AO process. The dominant microorganisms at the phylum level in all reactors were Proteobacteria and Bacteroidetes, while the abundance of Nitrospira was the highest in SBRH with relatively lowest dissolved oxygen concentrations.
Collapse
Affiliation(s)
- Huoqing Wang
- a Guangdong Province Engineering Research Center for Urban Water Recycling and Environmental Safety, Graduate School at Shenzhen , Tsinghua University , Shenzhen , People's Republic of China
| | - Yuepeng Sun
- a Guangdong Province Engineering Research Center for Urban Water Recycling and Environmental Safety, Graduate School at Shenzhen , Tsinghua University , Shenzhen , People's Republic of China
| | - Guangxue Wu
- a Guangdong Province Engineering Research Center for Urban Water Recycling and Environmental Safety, Graduate School at Shenzhen , Tsinghua University , Shenzhen , People's Republic of China
| | - Yuntao Guan
- a Guangdong Province Engineering Research Center for Urban Water Recycling and Environmental Safety, Graduate School at Shenzhen , Tsinghua University , Shenzhen , People's Republic of China
| |
Collapse
|
10
|
Duan H, Wang Q, Erler DV, Ye L, Yuan Z. Effects of free nitrous acid treatment conditions on the nitrite pathway performance in mainstream wastewater treatment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 644:360-370. [PMID: 29981984 DOI: 10.1016/j.scitotenv.2018.06.346] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 06/27/2018] [Accepted: 06/27/2018] [Indexed: 06/08/2023]
Abstract
Inline sludge treatment using free nitrous acid (FNA) was recently shown to be effective in establishing the nitrite pathway in a biological nitrogen removal system. However, the effects of FNA treatment conditions on the nitrite pathway performance remained to be investigated. In this study, three different FNA treatment frequencies (daily sludge treatment ratios of 0.22, 0.31 and 0.38, respectively), two FNA concentrations (1.35 mgN/L and 4.23 mgN/L, respectively) and two influent feeding regimes (one- and two-step feeding) were investigated in four laboratory-scale sequencing batch reactors. The nitrite accumulation ratio was positively correlated to the FNA treatment frequency. However, when a high treatment frequency was used e.g., daily sludge treatment ratio of 0.38, a significant reduction in ammonia oxidizing bacteria (AOB) activity occurred, leading to poor ammonium oxidation. AOB were able to acclimatise to FNA concentrations up to of 4.23 mgN/L, whereas nitrite oxidizing bacteria (NOB) were limited by an FNA concentration of 1.35 mgN/L over the duration of the study (up to 120 days). This difference in sensitivity to FNA could be used to further enhance nitrite accumulation, with 90% accumulation achieved at an FNA concentration of 4.23 mgN/L and a daily sludge treatment ratio of 0.31 in this study. However, this high level of nitrite accumulation led to increased N2O emission, with emission factors of up to 3.9% observed. The N2O emission was mitigated (reduced to 1.3%) by applying two-step feeding resulting in a nitrite accumulation ratio of 45.1%. Economic analysis showed that choosing the optimal FNA treatment conditions depends on a combination of the wastewater characteristics, the nitrogen discharge standards, and the operational costs. This study provides important information for the optimisation and practical application of FNA-based sludge treatment technology for achieving the mainstream stable nitrite pathway.
Collapse
Affiliation(s)
- Haoran Duan
- Advanced Water Management Centre (AWMC), The University of Queensland, St Lucia, QLD 4072, Australia
| | - Qilin Wang
- Advanced Water Management Centre (AWMC), The University of Queensland, St Lucia, QLD 4072, Australia; Griffith School of Engineering, Griffith University, QLD, Australia; Centre for Clean Environment and Energy, Environmental Futures Research Institute, Griffith University, QLD, Australia.
| | - Dirk V Erler
- Centre for Coastal Biogeochemistry, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW 2480, Australia
| | - Liu Ye
- School of Chemical Engineering, The University of Queensland, St. Lucia, Brisbane, QLD, 4072, Australia
| | - Zhiguo Yuan
- Advanced Water Management Centre (AWMC), The University of Queensland, St Lucia, QLD 4072, Australia.
| |
Collapse
|
11
|
Choi D, Cho S, Jung J. Key operating parameters affecting nitrogen removal rate in single-stage deammonification. CHEMOSPHERE 2018; 207:357-364. [PMID: 29803885 DOI: 10.1016/j.chemosphere.2018.05.053] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 03/29/2018] [Accepted: 05/08/2018] [Indexed: 06/08/2023]
Abstract
The key operating parameters for improving the nitrogen removal rate (NRR) in a sequencing batch reactor (SBR) for deammonification were investigated. The major operating strategies were the coexistence between deammonification and denitrification with a carbon/nitrogen (C/N) ratio of 0.5 and the control of the number of sub-cycles based on substrate concentration for anaerobic ammonium oxidation (ANAMMOX) and ammonium oxidizing bacteria (AOB). In the study, denitrification with the addition of an organic source was beneficial for improving the NRR from 0.5 ± 0.01 kg N m-3 d-1 to 0.53 ± 0.01 kg N m-3 d-1 by removing the nitrate produced as a by-product of ANAMMOX. Unlike the gradual increase of the specific activity for AOB, the specific ANAMMOX activity (SAA) was maximized when an ammonium concentration supplied after sub-feeding phase was increased from 20 to 100 mg L-1, which increased the NRR from 0.53 ± 0.01 kg N m-3 d-1 to 0.79 ± 0.01 kg N m-3 d-1. This result suggested that the SAA is more important than the specific activity for AOB as a parameter for controlling the NRR in the single-stage deammonification. In the whole experimental period, the granule size smaller than 100 μm accounted for 52.5 ± 0.9%, making the largest contribution to the activity for AOB and denitrifiers. However, the granule size larger than 100 μm made the greatest contribution (83.8 ± 0.5%) to SAA. The feasibility of using the derivate of pH and OPR as indirect parameters to control the NRR was verified.
Collapse
Affiliation(s)
- Daehee Choi
- Department of Environmental Engineering, Yeungnam University, 280 Daehak-Ro, Gyeongsan-Si, Gyeongbuk 38541, Republic of Korea
| | - Sukhyun Cho
- Department of Environmental Engineering, Yeungnam University, 280 Daehak-Ro, Gyeongsan-Si, Gyeongbuk 38541, Republic of Korea
| | - Jinyoung Jung
- Department of Environmental Engineering, Yeungnam University, 280 Daehak-Ro, Gyeongsan-Si, Gyeongbuk 38541, Republic of Korea.
| |
Collapse
|
12
|
Sun Y, Wang H, Wu G, Guan Y. Nitrogen removal and nitrous oxide emission from a step-feeding multiple anoxic and aerobic process. ENVIRONMENTAL TECHNOLOGY 2018; 39:814-823. [PMID: 28345390 DOI: 10.1080/09593330.2017.1311947] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Accepted: 03/22/2017] [Indexed: 06/06/2023]
Abstract
The multiple anoxic and aerobic (AO) process is an advanced biological nitrogen-removal process, and nitrous oxide (N2O) emission might affect its sustainable application. Nitrogen removal and N2O emission in a step-feeding multiple AO sequencing batch reactor (SBRS) was examined, in comparison with a one-feeding sequencing batch reactor (SBRO). Nitrogen removal was enhanced by 12.6% in SBRS compared to the removal percentage of 75.8% in SBRO. Activated sludge in SBRs possessed a higher N2O emission factor during nitrification, denitrification and simultaneous nitrification and denitrification (SND) than in SBRO. A high N2O emission factor was observed during SND in both reactors, with the emission factor of 4.38% in SBRS and 4.66% in SBRO. More N2O emission occurred in the presence of nitrite. Bacteroidetes and Proteobacteria dominated in both SBRS and SBRO. A similar abundance of Thauera, Dechloromonas and Zoogloea possible for denitrification was observed in SBRS and SBRO. Moreover, nosZ from Proteobacteria dominated in both SBRS and SBRO, with dominating genus of Acidovorax, Ralstonia, Thauera and Marinobacter.
Collapse
Affiliation(s)
- Yuepeng Sun
- a Key Laboratory of Microorganism Application and Risk Control (MARC) of Shenzhen, Graduate School at Shenzhen , Tsinghua University , Shenzhen , People's Republic of China
| | - Huoqing Wang
- a Key Laboratory of Microorganism Application and Risk Control (MARC) of Shenzhen, Graduate School at Shenzhen , Tsinghua University , Shenzhen , People's Republic of China
| | - Guangxue Wu
- a Key Laboratory of Microorganism Application and Risk Control (MARC) of Shenzhen, Graduate School at Shenzhen , Tsinghua University , Shenzhen , People's Republic of China
| | - Yuntao Guan
- a Key Laboratory of Microorganism Application and Risk Control (MARC) of Shenzhen, Graduate School at Shenzhen , Tsinghua University , Shenzhen , People's Republic of China
| |
Collapse
|
13
|
Li W, Sun Y, Bian R, Wang H, Zhang D. N 2O emissions from an intermittently aerated semi-aerobic aged refuse bioreactor: Combined effect of COD and NH 4+-N in influent leachate. WASTE MANAGEMENT (NEW YORK, N.Y.) 2017; 69:242-249. [PMID: 28811146 DOI: 10.1016/j.wasman.2017.08.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 06/30/2017] [Accepted: 08/09/2017] [Indexed: 06/07/2023]
Abstract
The carbon-nitrogen ratio (COD/NH4+-N) is an important factor affecting nitrification and denitrification in wastewater treatment; this factor also influences nitrous oxide (N2O) emissions. This study investigated two simulated intermittently aerated semi-aerobic aged refuse bioreactors (SAARB) filled with 8-year old aged refuse (AR). The research analyzed how differences in and the combination of influent COD and NH4+-N impact N2O emissions in leachate treatment. Experimental results showed that N2O emissions increased as the influent COD/NH4+-N decreased. The influent COD had a greater effect on N2O emissions than NH4+-N at the same influent ratios of COD/NH4+-N (2.7 and 8.0, respectively). The maximum N2O emission accounted for 8.82±2.65% of the total nitrogen removed from the influent leachate; the maximum level occurred when the COD was 2000mg/L. An analysis of differences in influent carbon sources at the same COD/NH4+-N ratios concluded that the availability of biodegradable carbon substrates (i.e. glucose) is an important factor affecting N2O emissions. At a low influent COD/NH4+-N ratio (2.7), the N2O conversion rate was greater when there were more biodegradable carbon substrates. Although the SAARB included the N2O generation and reduction processes, N2O reduction mainly occurred later in the process, after leachate recirculation. The maximum N2O emission rate occurred in the first hour of single-period (24h) experiments, as leachate contacted the surface AR. In practical SAARB applications, N2O emissions may be reduced by measures such as reducing the initial recirculation loading of NH4+-N substrates, adding a later supplement of biodegradable carbon substrates, and/or prolonging hydraulic retention time (HRT) of influent leachate.
Collapse
Affiliation(s)
- Weihua Li
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266033, PR China
| | - Yingjie Sun
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266033, PR China.
| | - Rongxing Bian
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
| | - Huawei Wang
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266033, PR China
| | - Dalei Zhang
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266033, PR China
| |
Collapse
|
14
|
Yan X, Zheng J, Han Y, Liu J, Sun J. Effect of influent C/N ratio on N 2O emissions from anaerobic/anoxic/oxic biological nitrogen removal processes. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:23714-23724. [PMID: 28864852 DOI: 10.1007/s11356-017-0019-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 08/23/2017] [Indexed: 06/07/2023]
Abstract
The problem of producing strong greenhouse gas of nitrous oxide (N2O) from biological nitrogen removal (BNR) process in wastewater treatment plants (WWTP) has elicited great concern from various sectors. In this study, three laboratory-scale wastewater treatment systems, with influent C/N ratios of 3.4, 5.4, and 7.5, were set up to study the effect of influent C/N ratio on N2O generation in anaerobic/anoxic/oxic (A2O) process. Results showed, with the increased influent C/N ratio, N2O generation from both nitrification and denitrification process was decreased, and the N2O-N conversion ratio of the process was obviously reduced from 2.23 to 0.05%. Nitrification rate in oxic section was reduced, while denitrification rate in anaerobic and anoxic section was elevated and the removal efficiency of COD, NH4+-N, TN, and TP was enhanced in different extent. As the C/N ratio increased from 3.4 to 7.5, activities of three key denitrifying enzymes of nitrate reductase, nitrite reductase, and nitrous oxide reductase were increased. Moreover, microorganism analysis indicated that the relative abundance of ammonium-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) were positively correlated with N2O generation, which was reduced from (8.42 ± 3.65) to (3.61 ± 1.66)% and (10.38 ± 4.12) to (4.67 ± 1.62)%, respectively. NosZ gene copy numbers of the A2O system were increased from (1.19 ± 0.49) × 107 to (2.84 ± 0.54) × 108 copies/g MLSS with the influent C/N ratio elevated from 3.4 to 7.5. Hence, appropriate influent C/N condition of A2O process could optimize the microbial community structure that simultaneously improve treatment efficiency and decrease the N2O generation.
Collapse
Affiliation(s)
- Xu Yan
- School of Environment, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Henan Normal University, Xinxiang, Henan, 453007, China.
| | - Jiaxi Zheng
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Yunping Han
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Jianwei Liu
- Beijing Engineering Research Center of Sustainable Urban Sewage System Construction and Risk Control, Beijing University of Civil Engineering and Architecture, Beijing, China
| | - Jianhui Sun
- School of Environment, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Henan Normal University, Xinxiang, Henan, 453007, China
| |
Collapse
|
15
|
Microbial nitrification, denitrification and respiration in the leached cinnamon soil of the upper basin of Miyun Reservoir. Sci Rep 2017; 7:42032. [PMID: 28165035 PMCID: PMC5292740 DOI: 10.1038/srep42032] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 01/03/2017] [Indexed: 11/30/2022] Open
Abstract
Leached cinnamon soil is the main agricultural soil distributed in the North China Plain. In this research, leached cinnamon soil samples were collected in the upper basin of Miyun Reservoir (northeast of Beijing, China). The BaPS method (Barometric Process Separation) was applied to measure nitrification, denitrification and respiration rates. The rates of nitrification, denitrification and respiration were 0–120.35 μg N/kg SDW h, 0–246.86 μg N/kg SDW h and 0.17–225.85 μg C/kg SDW h (Soil Dry Weight, SDW), respectively. The emission rates of CO2 and NxOy through nitrification, denitrification and respiration were 1.00–547.80 and 6.00–4850.65 μmol/h, respectively. The analysis of relationships between nitrification, denitrification and respiration rates indicated that these three microbial processes were interacted, which posed impacts on soil nitrogen availability. As indicated by the results, C:N ratio coupled with content could be taken as the indicators of content, which is usually the predominant form of N available to plants growing in soil. Results showed that content was the highest (i.e., >62.4 mg/kg) when C:N ratio was 5.30–8.40, meanwhile content was 3.71–4.39 mg/kg. Nevertheless, content was the lowest (i.e., <6.40 mg/kg) when C:N ratio was 9.2–12.10, meanwhile content was 3.41–4.35 mg/kg.
Collapse
|
16
|
Li H, Pan M, Zhou S, Huang S, Zhang Y. Characterization of nitrous oxide emissions from a thermophilic denitrifying bacterium Chelatococcus daeguensis TAD1 in an aerated sequencing batch reactor. Biochem Eng J 2016. [DOI: 10.1016/j.bej.2016.04.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
17
|
Jia W, Wang Q, Zhang J, Yang W, Zhou X. Nutrients removal and nitrous oxide emission during simultaneous nitrification, denitrification, and phosphorus removal process: effect of iron. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:15657-15664. [PMID: 27137189 DOI: 10.1007/s11356-016-6758-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 04/25/2016] [Indexed: 06/05/2023]
Abstract
The short- and long-term influences of ferric iron (Fe(III)) on nutrients removal and nitrous oxide (N2O) emission during SNDPR process were evaluated. According to the continuous cycle experiments, it was concluded that the addition of Fe(III) could lower the nitrogen removal of the following cycle during SNDPR process, which was mainly induced by the chemical removal of phosphorus. However, the impacts were transitory, and simultaneous nitrogen and phosphorus removal would recover from the inhibition of Fe(III) after running certain cycles. Moreover, the addition of Fe(III) could stimulate N2O emission transitorily during SNDPR process. However, if Fe(III) was added into reactor continuously, the nitrogen removal would be improved, especially at low Fe load condition. It was because that the activity of NO reductase was enhanced by the addition of Fe. However, the low Fe load in reactor would induce more N2O emission. When Fe(III) load was 40 mg/L in the reactor, the N2O yield was 10 % higher than control. The TN removal was weakened when Fe(III) load reached to 60 mg/L, and the N2O yield was lower than control, due to the inhibition of the high Fe load on denitrification enzymes.
Collapse
Affiliation(s)
- Wenlin Jia
- School of Chemistry and Chemical Engineering, Jiangsu Normal University, Xuzhou, 221116, China.
| | - Qian Wang
- School of Chemistry and Chemical Engineering, Jiangsu Normal University, Xuzhou, 221116, China
| | - Jian Zhang
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China
| | - Weihua Yang
- School of Chemistry and Chemical Engineering, Jiangsu Normal University, Xuzhou, 221116, China
| | - Xiaowei Zhou
- School of Chemistry and Chemical Engineering, Jiangsu Normal University, Xuzhou, 221116, China
| |
Collapse
|
18
|
Guo J, Fu X, Andrés Baquero G, Sobhani R, Nolasco DA, Rosso D. Trade-off between carbon emission and effluent quality of activated sludge processes under seasonal variations of wastewater temperature and mean cell retention time. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 547:331-344. [PMID: 26789371 DOI: 10.1016/j.scitotenv.2015.12.102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 12/07/2015] [Accepted: 12/21/2015] [Indexed: 06/05/2023]
Abstract
Over the seasonal cycles, the mean cell retention time (MCRT) of the activated sludge process is varied to compensate the wastewater temperature variations. The effects of these variations on the carbon footprint (CFP) and effluent quality index (EQI) of a conventional activated sludge (CAS) process and a nitrification/denitrification (NDN) process were quantified. The carbon emission included both biogenic and non-biogenic carbon. Carbon emissions of wasted biosolids management were also addressed. Our results confirmed that the effluent quality indicated by EQI was not necessarily improved by increasing MCRT. Higher MCRT increased the carbon emission and reduced excess sludge production, which decreased the potential for biogas energy recovery. The NDN process was preferable to the CAS process from the perspective of effluent quality. This consideration extended to the whole plant CFP if the N2O emitted during NDN was limited ([N2O]<1% [NH4(+)]removed) as the carbon emission per unit effluent quality achieved by NDN process is less than that of the CAS process. By putting forward carbon emission intensity (γ) derived from CFP and EQI, our work provides a quantitative tool for decision makers evaluating process alternatives when there is a trade-off between carbon emission and effluent quality.
Collapse
Affiliation(s)
- Jingbo Guo
- School of Civil and Architecture Engineering, Northeast Dianli University, Jilin 132012, PR China.
| | - Xin Fu
- School of Civil and Architecture Engineering, Northeast Dianli University, Jilin 132012, PR China
| | - G Andrés Baquero
- Ciencia e Ingeniería del Agua y el Ambiente, Pontificia Universidad Javeriana, Carrera 7 No. 40-62, Bogotá D.C., Colombia
| | - Reza Sobhani
- Water-Energy Nexus Center, University of California, Irvine, CA 92697-2175, USA
| | - Daniel A Nolasco
- Water-Energy Nexus Center, University of California, Irvine, CA 92697-2175, USA; Nolasco y Asociados, S.A., Congreso 1908, Piso 2D, Buenos Aires C1428BVB, Argentina
| | - Diego Rosso
- Water-Energy Nexus Center, University of California, Irvine, CA 92697-2175, USA; Department of Civil and Environmental Engineering, University of California, Irvine, CA 92697-2175, USA
| |
Collapse
|
19
|
Yan X, Han Y, Li Q, Sun J, Su X. Impact of internal recycle ratio on nitrous oxide generation from anaerobic/anoxic/oxic biological nitrogen removal process. Biochem Eng J 2016. [DOI: 10.1016/j.bej.2015.11.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
20
|
Ren Y, Wang J, Xu L, Liu C, Zong R, Yu J, Liang S. Direct emissions of N2O, CO 2, and CH 4 from A/A/O bioreactor systems: impact of influent C/N ratio. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:8163-8173. [PMID: 25850740 DOI: 10.1007/s11356-015-4408-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Accepted: 03/18/2015] [Indexed: 06/04/2023]
Abstract
Direct emissions of N2O, CO2, and CH4, three important greenhouse gases (GHGs), from biological sewage treatment process have attracted increasing attention worldwide, due to the increasing concern about climate change. Despite the tremendous efforts devoted to understanding GHG emission from biological sewage treatment process, the impact of influent C/N ratios, in terms of chemical oxygen demand (COD)/total nitrogen (TN), on an anaerobic/anoxic/oxic (A/A/O) bioreactor system has not been investigated. In this work, the direct GHG emission from A/A/O bioreactor systems fed with actual sewage was analyzed under different influent C/N ratios over a 6-month period. The results showed that the variation in influent carbon (160 to 500 mg/L) and nitrogen load (35 to 95 mg/L) dramatically influenced pollutant removal efficiency and GHG production from this process. In the A/A/O bioreactor systems, the GHG production increased from 26-39 to 112-173 g CO2-equivalent as influent C/N ratios decreased from 10.3/10.7 to 3.5/3.8. Taking consideration of pollutant removal efficiency and direct biogenic GHG (N2O, CO2, and CH4) production, the optimum influent C/N ratio was determined to be 7.1/7.5, at which a relatively high pollutant removal efficiency and meanwhile a low level of GHG production (30.4 g CO2-equivalent) can be achieved. Besides, mechanical aeration turned out to be the most significant factor influencing GHG emission from the A/A/O bioreactor systems.
Collapse
Affiliation(s)
- Yangang Ren
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan, People's Republic of China
| | | | | | | | | | | | | |
Collapse
|
21
|
Song K, Riya S, Hosomi M, Terada A. Effect of carbon sources on nitrous oxide emission in a modified Ludzak Ettinger process. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2015; 72:572-578. [PMID: 26247755 DOI: 10.2166/wst.2015.250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Effect of methanol and glycerol on nitrous oxide (N2O) emission in two laboratory-scale modified Ludzak Ettinger (MLE) processes was investigated during three distinct periods: dissolved oxygen (DO) control by intermittent aeration with a DO controller, and high and low aeration rates. N2O consumption rate in an anoxic tank and aeration mode influenced N2O emission rates from the MLE processes. In the DO control period, N2O emission rate from the glycerol-fed MLE process was higher than the methanol-fed counterpart, likely caused by a higher N2O consumption rate in an anoxic tank of the methanol-fed process. During the period of a higher aeration rate, N2O emission rates from both processes were comparable. In contrast, during the period of a lower aeration rate, N2O emission rate from the methanol-fed MLE process was higher than that from the glycerol-fed counterpart likely because of a higher degree of nitrite accumulation, corroborated by statistical analysis. N2O consumption activities of biomasses fed with the different carbon sources were distinct. However, the high activity did not necessarily result in a decrease in N2O emission rate from an aerobic tank and the effect of nitrite on the emission was stronger under the tested conditions.
Collapse
Affiliation(s)
- Kang Song
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan E-mail:
| | - Shohei Riya
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan E-mail:
| | - Masaaki Hosomi
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan E-mail:
| | - Akihiko Terada
- Department of Chemical Engineering, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan E-mail:
| |
Collapse
|
22
|
Castro-Barros CM, Daelman MRJ, Mampaey KE, van Loosdrecht MCM, Volcke EIP. Effect of aeration regime on N₂O emission from partial nitritation-anammox in a full-scale granular sludge reactor. WATER RESEARCH 2015; 68:793-803. [PMID: 25465719 DOI: 10.1016/j.watres.2014.10.056] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 08/23/2014] [Accepted: 10/25/2014] [Indexed: 06/04/2023]
Abstract
N₂O emission from wastewater treatment plants is high of concern due to the strong environmental impact of this greenhouse gas. Good understanding of the factors affecting the emission and formation of this gas is crucial to minimize its impact. This study addressed the investigation of the N₂O emission dynamics in a full-scale one-stage granular sludge reactor performing partial nitritation-anammox (PNA) operated at a N-loading of 1.75 kg NH₄⁺-N m⁻³ d⁻¹. A monitoring campaign was conducted, gathering on-line data of the N₂O concentration in the off-gas of the reactor as well as of the ammonium and nitrite concentrations in the liquid phase. The N₂O formation rate and the liquid N₂O concentration profile were calculated from the gas phase measurements. The mean (gaseous) N₂O-N emission obtained was 2.0% of the total incoming nitrogen during normal reactor operation. During normal operation of the reactor under variable aeration rate, intense aeration resulted in higher N₂O emission and formation than during low aeration periods (mean N₂O formation rate of 0.050 kg N m⁻³ d⁻¹ for high aeration and 0.029 kg N m⁻³ d⁻¹ for low aeration). Accumulation of N₂O in the liquid phase was detected during low aeration periods and was accompanied by a relatively lower ammonium conversion rate, while N₂O stripping was observed once the aeration was increased. During a dedicated experiment, gas recirculation without fresh air addition into the reactor led to the consumption of N₂O, while accumulation of N₂O was not detected. The transition from a prolonged period without fresh air addition and with little recirculation to enhanced aeration with fresh air addition resulted in the highest N₂O formation (0.064 kg N m⁻³ d⁻¹). The results indicate that adequate aeration control may be used to minimize N₂O emissions from PNA reactors.
Collapse
Affiliation(s)
- C M Castro-Barros
- Department of Biosystems Engineering, Ghent University, Coupure Links 653, 9000 Gent, Belgium.
| | | | | | | | | |
Collapse
|
23
|
Eldyasti A, Nakhla G, Zhu J. Influence of biofilm thickness on nitrous oxide (N2O) emissions from denitrifying fluidized bed bioreactors (DFBBRs). J Biotechnol 2014; 192 Pt A:281-90. [DOI: 10.1016/j.jbiotec.2014.10.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 10/07/2014] [Accepted: 10/08/2014] [Indexed: 11/25/2022]
|
24
|
Eldyasti A, Nakhla G, Zhu J. Mitigation of nitrous oxide (N2O) emissions from denitrifying fluidized bed bioreactors (DFBBRs) using calcium. BIORESOURCE TECHNOLOGY 2014; 173:272-283. [PMID: 25310863 DOI: 10.1016/j.biortech.2014.09.121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 09/19/2014] [Accepted: 09/23/2014] [Indexed: 06/04/2023]
Abstract
Nitrous oxide (N2O) is a significant anthropogenic greenhouse gases (AnGHGs) emitted from biological nutrient removal (BNR) processes. In this study, N2O production from denitrifying fluidized bed bioreactors (DFBBR) was reduced using calcium (Ca2+) dosage. The DFBBRs were operated on a synthetic municipal wastewater at four different calcium concentrations ranging from the typical municipal wastewater Ca2+ concentration (60 mg Ca2+/L) to 240 mg Ca2+/L at two different COD/N ratios. N2O emission rates, extracellular polymeric substances (EPS), water quality parameters, and microscopic images were monitored regularly in both phases. Calcium concentrations played a significant role in biofilm morphology with the detachment rates for R120Ca, R180Ca, and R240Ca 75% lower than for R60Ca, respectively. The N2O conversion rate at the typical municipal wastewater Ca2+ concentration (R60Ca) was about 0.53% of the influent nitrogen loading as compared with 0.34%, 0.42%, and 0.41% for R120Ca, R180Ca, and R240Ca, respectively corresponding to 21-36% reduction.
Collapse
Affiliation(s)
- Ahmed Eldyasti
- Department of Civil Engineering, Lassonde School of Engineering, York University, Toronto, Ontario M3J 1P3, Canada; Department of Civil and Environmental Engineering, The University of Western Ontario, London, Ontario N6A 5B9, Canada
| | - George Nakhla
- Department of Civil and Environmental Engineering, The University of Western Ontario, London, Ontario N6A 5B9, Canada; Department of Chemical and Biochemical Engineering, The University of Western Ontario, London, Ontario N6A 5B9, Canada.
| | - Jesse Zhu
- Department of Chemical and Biochemical Engineering, The University of Western Ontario, London, Ontario N6A 5B9, Canada
| |
Collapse
|
25
|
Hu Z, Lee JW, Chandran K, Kim S, Sharma K, Khanal SK. Influence of carbohydrate addition on nitrogen transformations and greenhouse gas emissions of intensive aquaculture system. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 470-471:193-200. [PMID: 24140689 DOI: 10.1016/j.scitotenv.2013.09.050] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 09/12/2013] [Accepted: 09/17/2013] [Indexed: 06/02/2023]
Abstract
Aquaculture is one of the fastest-growing segments of the food economy in modern times. It is also being considered as an important source of greenhouse gas (GHG) emissions. To date, limited studies have been conducted on GHG emissions from aquaculture system. In this study, daily addition of fish feed and soluble starch at a carbon-to-nitrogen (C/N) ratio of 16:1 (w/w) was used to examine the effects of carbohydrate addition on nitrogen transformations and GHG emissions in a zero-water exchange intensive aquaculture system. The addition of soluble starch stimulated heterotrophic bacterial growth and denitrification, which led to lower total ammonia nitrogen, nitrite and nitrate concentrations in aqueous phase. About 76.2% of the nitrogen output was emitted in the form of gaseous nitrogen (i.e., N2 and N2O) in the treatment tank (i.e., aquaculture tank with soluble starch addition), while gaseous nitrogen accounted for 33.3% of the nitrogen output in the control tank (i.e., aquaculture tank without soluble starch addition). Although soluble starch addition reduced daily N2O emissions by 83.4%, it resulted in an increase of daily carbon dioxide (CO2) emissions by 91.1%. Overall, starch addition did not contribute to controlling the GHG emissions from the aquaculture system.
Collapse
Affiliation(s)
- Zhen Hu
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China
| | - Jae Woo Lee
- Department of Environmental Engineering, College of Science and Technology, Korea University, Sejong-ro 2511, Sejong 339-700, South Korea
| | - Kartik Chandran
- Department of Earth and Environmental Engineering, Columbia University, 500 West 120th Street, New York, NY 10027, USA
| | - Sungpyo Kim
- Department of Environmental Engineering, College of Science and Technology, Korea University, Sejong-ro 2511, Sejong 339-700, South Korea
| | - Keshab Sharma
- Advanced Water Management Centre, University of Queensland, St. Lucia, QLD 4072, Australia
| | - Samir Kumar Khanal
- Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu, HI 96822, USA.
| |
Collapse
|
26
|
Yang S, Gao MM, Liang S, Wang SG, Wang XH. Effects of step-feed on long-term performances and N2O emissions of partial nitrifying granules. BIORESOURCE TECHNOLOGY 2013; 143:682-685. [PMID: 23849754 DOI: 10.1016/j.biortech.2013.06.066] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 06/17/2013] [Accepted: 06/19/2013] [Indexed: 06/02/2023]
Abstract
This study used two anoxic/oxic sequencing batch reactors (A/O SBRs) respectively with pulse-feed (PF-SBR) and step-feed (SF-SBR) to investigate the effects of step-feed on partial nitrifying granules. The stable partial nitrification lasted 111 and 139 days in PF-SBR and SF-SBR, and then gradually switched to full nitrification. Granules in both reactors showed similar physical properties and excellent ammonia removal performances throughout 253 days operations. The SF-SBR had significantly higher total nitrogen (TN) removal efficiency than the PF-SBR. Based on long-term monitoring, the N2O emissions in SF-SBR decreased 53.8% and 61.6% during partial and full nitrification as compared with that in PF-SBR. Although the removed TN was very limited, most of the N2O was emitted during oxic phases. The percentage of N2O emission to TN removed during oxic phases was 90.75% and 47.21% for PF-SBR, 55.09% and 29.55% for SF-SBR, respectively under partial and full nitrification modes.
Collapse
Affiliation(s)
- Sen Yang
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China
| | | | | | | | | |
Collapse
|