1
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Stark BM, Tian K, Krause MJ. Investigation of U.S. landfill GHG reporting program methane emission models. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 186:86-93. [PMID: 38865908 DOI: 10.1016/j.wasman.2024.05.037] [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: 11/06/2023] [Revised: 05/03/2024] [Accepted: 05/23/2024] [Indexed: 06/14/2024]
Abstract
As part of its commitment to the United Nations Framework Convention on Climate Change, the U.S. annually develops a national estimate of methane emissions from municipal solid waste (MSW) landfills by aggregating activity data from each facility. Since 2010, the U.S. has reported a 20 % decrease in MSW landfill emissions despite a 21 % increase in tons disposed. Operator-submitted data were investigated to understand the causes of this decline. In the U.S., operators of landfills with a gas collection and control system (GCCS) calculate their facility's emissions via two separate approaches - (1) first-order decay (FOD) and (2) collection efficiency assumption (CEA) - and select either result to feed into the annual inventory. The FOD model predicts methane generation proportional to waste disposal and that approach calculated a 19 % increase in total methane generated from 2010 to 2022, whereas generation via the CEA approach decreased by 8.9 %. The amount of measured methane collected has increased 7.5 % for the same years. Discrepancies between the two models' generated methane, assumed gas collection efficiencies, and oxidized methane compound into substantive differences in national estimates. Operators more frequently select the CEA method, which results in decreased national estimates. If only the FOD method was used, U.S. MSW landfill emissions would be 1.3-1.7 times greater than current estimates which is similar to recent extrapolations from remote sensing campaigns in the U.S. Both models contain parameters with large inherent uncertainty. Without measurement methods that continuously quantify both point-source and diffuse emissions, an assessment of either equation's accuracy cannot be made.
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Affiliation(s)
- Benjamin M Stark
- George Mason University, 4400 University Drive, Fairfax, VA 22030, USA
| | - Kuo Tian
- George Mason University, 4400 University Drive, Fairfax, VA 22030, USA.
| | - Max J Krause
- US EPA Office of Research & Development, 26 W Martin Luther King Dr, Cincinnati, OH 45268, USA.
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2
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Manheim DC, Yeşiller N, Hanson JL, Blake DR. Climate impacts of landfill gas emissions: Analysis for 20-year and 100-year time horizons. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 186:318-330. [PMID: 38954923 DOI: 10.1016/j.wasman.2024.06.015] [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: 10/19/2023] [Revised: 05/17/2024] [Accepted: 06/18/2024] [Indexed: 07/04/2024]
Abstract
Climate impacts of landfill gas emissions were investigated for 20- and 100-year time horizons to identify the effects of atmospheric lifetimes of short- and long-lived drivers. Direct and indirect climate impacts were determined for methane and 79 trace species. The impacts were quantified using global warming potential, GWP (direct and indirect); atmospheric degradation (direct); tropospheric ozone forming potential (indirect); secondary aerosol forming potential (indirect) and stratospheric ozone depleting potential (indirect). Effects of cover characteristics, landfill operational conditions, and season on emissions were assessed. Analysis was conducted at five operating municipal solid waste landfills in California, which collectively contained 13% of the waste in place in the state. Climate impacts were determined to be primarily due to direct emissions (99.5 to 115%) with indirect emissions contributing -15 to 0.5%. Methane emissions were 35 to 99% of the total emissions and the remainder mainly greenhouse gases (hydro)chlorofluorocarbons (up to 42% of total emissions) and nitrous oxide. Cover types affected emissions, where the highest emissions were generally from intermediate covers with the largest relative landfill surface areas. Landfill-specific direct emissions varied between 683 and 103,411 and between 381 and 37,925 Mg CO2-eq./yr for 20- and 100-yr time horizons, respectively. Total emissions (direct + indirect) were 680 to 103,600 (20-yr) and were 374 to 38,108 (100-yr) Mg CO2-eq./yr. Analysis time horizon significantly affected emissions. The 20-yr direct and total emissions were consistently higher than the 100-yr emissions by up to 2.5 times. Detailed analysis of time-dependent climate effects can inform strategies to mitigate climate change impacts of landfill gas emissions.
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Affiliation(s)
- Derek C Manheim
- Global Waste Research Institute, California Polytechnic State University, San Luis Obispo, CA, 93407, USA; Civil and Environmental Engineering Department, California Polytechnic State University, San Luis Obispo, CA, 93407, USA.
| | - Nazli Yeşiller
- Global Waste Research Institute, California Polytechnic State University, San Luis Obispo, CA, 93407, USA
| | - James L Hanson
- Civil and Environmental Engineering Department, California Polytechnic State University, San Luis Obispo, CA, 93407, USA
| | - Donald R Blake
- Department of Chemistry, University of California-Irvine, Irvine, CA, 92697, USA
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3
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Al-Heetimi OT, Van De Ven CJC, Van Geel PJ, Rayhani MT. Impact of temperature on the performance of compost-based landfill biocovers. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 344:118780. [PMID: 37611345 DOI: 10.1016/j.jenvman.2023.118780] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 07/17/2023] [Accepted: 08/09/2023] [Indexed: 08/25/2023]
Abstract
Methane (CH4) emissions from landfills are a major contributor to global greenhouse gas emissions. Compost-based biocovers offer a viable approach to reduce CH4 emissions from landfills; however, the effectiveness in climates with varying temperatures is not well understood. The methane removal performances of two compost-based biocover materials (food and yard waste compost) were examined under different temperature conditions using laboratory column experiments. A reactive transport model was used to simulate the experimental results to develop a better quantitative understanding of the effect of temperature on overall methane removal efficiency. As expected, experimental results indicated that the oxidation rate was influenced by temperature, as it was reduced when the temperature decreased from 22 °C to 8 °C. However, some oxidation was observed at a lower temperature, which was confirmed by CO2 concentrations above the initial level and the observed temperatures above the exposure temperature along the height of biocover column. Furthermore, results showed that when the compost-based materials were subjected to 8 °C and then increased to 22 °C, methane oxidation within the material recovered quickly and returned to similar oxidation rates as observed before the temperature was reduced, suggesting that compost-based biocovers may not be affected by cyclic temperature variations when used in colder climates. Methane oxidation capacity was limited by the maximum oxidation rate, the biocover porosity, and the gas saturation profile that affects residence time and overall methane oxidation in the columns. The model results show that the CH4 oxidation rate was reduced by one order of magnitude when the temperature decreased from 22 °C to 8 °C. Therefore, the calculated Q10 values were 4.19 and 5.18 for the food and yard waste compost, respectively. Overall, compost-based landfill biocovers, such as food and yard waste compost, are capable of mitigate CH4 emissions from old and small landfills under different temperature conditions.
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Affiliation(s)
- Oday T Al-Heetimi
- Carleton University, Dept. of Civil & Environmental Engineering, Ottawa, ON, K1S 5B6, Canada
| | - Cole J C Van De Ven
- Carleton University, Dept. of Civil & Environmental Engineering, Ottawa, ON, K1S 5B6, Canada.
| | - Paul J Van Geel
- Carleton University, Dept. of Civil & Environmental Engineering, Ottawa, ON, K1S 5B6, Canada
| | - Mohammad T Rayhani
- Carleton University, Dept. of Civil & Environmental Engineering, Ottawa, ON, K1S 5B6, Canada
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4
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Qin Y, Xi B, Sun X, Zhang H, Xue C, Wu B. Methane Emission Reduction and Biological Characteristics of Landfill Cover Soil Amended With Hydrophobic Biochar. Front Bioeng Biotechnol 2022; 10:905466. [PMID: 35757810 PMCID: PMC9213677 DOI: 10.3389/fbioe.2022.905466] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 04/28/2022] [Indexed: 11/13/2022] Open
Abstract
Biochar-amended landfill cover soil (BLCS) can promote CH4 and O2 diffusion, but it increases rainwater entry in the rainy season, which is not conducive to CH4 emission reduction. Hydrophobic biochar–amended landfill cover soil (HLCS) was prepared to investigate the changes in CH4 emission reduction and biological characteristics, and BLCS was prepared as control. Results showed that rainwater retention time in HLCS was reduced by half. HLCS had a higher CH4 reduction potential, achieving 100% CH4 removal at 25% CH4 content of landfill gas, and its main contributors to CH4 reduction were found to be at depths of 10–30 cm (upper layer) and 50–60 cm (lower layer). The relative abundances of methane-oxidizing bacteria (MOB) in the upper and lower layers of HLCS were 55.93% and 46.93%, respectively, higher than those of BLCS (50.80% and 31.40%, respectively). Hydrophobic biochar amended to the landfill cover soil can realize waterproofing, ventilation, MOB growth promotion, and efficient CH4 reduction.
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Affiliation(s)
- Yongli Qin
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin, China.,School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, China.,Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin, China
| | - Beidou Xi
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin, China.,State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Xiaojie Sun
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin, China.,Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin, China
| | - Hongxia Zhang
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin, China.,Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin, China
| | - Chennan Xue
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin, China.,Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin, China
| | - Beibei Wu
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin, China.,Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin, China
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5
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Anshassi M, Smallwood T, Townsend TG. Life cycle GHG emissions of MSW landfilling versus Incineration: Expected outcomes based on US landfill gas collection regulations. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 142:44-54. [PMID: 35176598 DOI: 10.1016/j.wasman.2022.01.040] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 01/27/2022] [Accepted: 01/30/2022] [Indexed: 06/14/2023]
Abstract
From a GHG perspective, most LCA studies find incineration (MSWI) to be preferred over landfilling because of high energy recovery offsets. In some studies, however, landfilling results in less greenhouse gases (GHG) emissions than MSWI. We investigated using LCA, the landfill gas (LFG) collection efficiencies and waste composition that led to landfills resulting in less GHG emissions. Then, we explored what theoretical minimum lifetime gas collection efficiencies can be expected when following US LFG regulations. Only landfills with high LFG collection efficiencies (at least 81%) and recovery of methane for energy resulted in less GHG emissions compared to the management of the same waste stream in MSWI; required efficiency increased to 93% without LFG energy recovery. Expected theoretical lifetime LFG collection efficiencies were modeled in the range of 30-80%, with the lower rates associated with landfills having smaller input masses, high decay rates, and low concentrations of nonmethane organic compounds (CNMOC). Our modeling found that only under a limited combination of conditions (e.g., high CNMOC, high waste input rate, low decay rate) could a landfill expect to achieve a LFG collection efficiency as high as 80%, and that this value falls just under the 81-93% collection efficiency threshold needed for a landfill to result in less GHG emissions than MSWI. When exploring the influence of higher oxidation rates, changing decay rates, varying electricity grids, and inclusion of nonferrous metals recovery offsets the collection effciency range needed increased in nearly all cases; the electricity grid and nonferrous metals offsets had the greatest influence.
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Affiliation(s)
- Malak Anshassi
- Department of Environmental Engineering Sciences, University of Florida, P. O. Box 116450, Gainesville, FL 32611-6450, USA
| | - Thomas Smallwood
- Department of Environmental Engineering Sciences, University of Florida, P. O. Box 116450, Gainesville, FL 32611-6450, USA
| | - Timothy G Townsend
- Department of Environmental Engineering Sciences, University of Florida, P. O. Box 116450, Gainesville, FL 32611-6450, USA.
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6
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Chi Z, Zhu Y, Yin Y. Insight into SO 4(-II)- dependent anaerobic methane oxidation in landfill: Dual-substrates dynamics model, microbial community, function and metabolic pathway. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 141:115-124. [PMID: 35114562 DOI: 10.1016/j.wasman.2022.01.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/18/2021] [Accepted: 01/20/2022] [Indexed: 06/14/2023]
Abstract
In anaerobic landfill, SO42- could serve as electron receptor for methane oxidation. In theory, concentrations of both methane and SO42- should be related to methane oxidation rate. However, the dynamics process has yet to be discovered, and the understanding of metabolic pathways of the sulfate-dependent anaerobic methane oxidation (S-DAMO) process in landfill remains limited. In this study, S-DAMO dynamics was investigated by observing the CH4 oxidation rates under different CH4/ SO42-counter-gradients. The CH4-SO42- dual-substrate model based on MichaeliseMenten equation was got (maximum substrate degradation rate Vmax [22.9 ± 1.31] µmol/[kg·d], half-saturation constants [Formula: see text] , and [Formula: see text] ). High-throughput sequencing analysis indicated Methanobacterials, Methanosarcinales, and Soil Crenarchaeotic were the main functional microorganisms for S-DAMO in landfill. The metabolic pathway of S-DAMO was speculated as the reverse methanogenesis pathway through Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUST) analysis, while methanogenesis was the methyl nutrition way based on methanol. The enzymes related to the carbon and sulfur cycles and their relative abundances in the microcosms were analyzed to graph the methane metabolic pathway and the sulfur metabolic pathway. The findings provide important parameters for CH4 mitigation in landfills, and give a new insight for understanding S-DAMO metabolic pathway in landfill.
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Affiliation(s)
- Zifang Chi
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, PR China.
| | - Yuhuan Zhu
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, PR China
| | - Ying Yin
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, PR China
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7
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Huang D, Du Y, Xu Q, Ko JH. Quantification and control of gaseous emissions from solid waste landfill surfaces. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 302:114001. [PMID: 34731706 DOI: 10.1016/j.jenvman.2021.114001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 10/18/2021] [Accepted: 10/23/2021] [Indexed: 06/13/2023]
Abstract
Landfilling is the most common option for solid waste disposal worldwide. Landfill sites can emit significant quantities of greenhouse gases (GHGs; e.g., methane, carbon dioxide, and nitrous oxide) and release toxic and odorous compounds (e.g., sulfides). Due to the complex composition and characteristics of landfill surface gas emissions, the quantification and control of landfill emissions are challenging. This review attempts to comprehensively understand landfill emission quantification and control options by primarily focusing on GHGs and odor compounds. Landfill emission quantification was highlighted by combining different emissions monitoring approaches to improve the quality of landfill emission data. Also, landfill emission control requires a specific approach that targets emission compounds or a systematic approach that reduces overall emissions by combining different control methods since the diverse factors dominate the emissions of various compounds and their transformation. This integrated knowledge of emission quantification and control options for GHGs and odor compounds is beneficial for establishing field monitoring campaigns and incorporating mitigation strategies to quantify and control multiple landfill emissions.
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Affiliation(s)
- Dandan Huang
- Key Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, Guangdong, 518055, China; School of Ecology, Sun Yat-sen University, Shenzhen, 518107, China
| | - Yue Du
- Key Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, Guangdong, 518055, China
| | - Qiyong Xu
- Key Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, Guangdong, 518055, China
| | - Jae Hac Ko
- Department of Environmental Engineering, College of Ocean Sciences, Jeju National University, Jeju Special Self-Governing Province, 63243, Republic of Korea.
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8
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Bakkaloglu S, Lowry D, Fisher RE, France JL, Nisbet EG. Carbon isotopic characterisation and oxidation of UK landfill methane emissions by atmospheric measurements. WASTE MANAGEMENT (NEW YORK, N.Y.) 2021; 132:162-175. [PMID: 34352589 DOI: 10.1016/j.wasman.2021.07.012] [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: 01/19/2021] [Revised: 06/15/2021] [Accepted: 07/11/2021] [Indexed: 06/13/2023]
Abstract
Biological oxidation of methane in landfill cover material can be calculated from the carbon isotopic signature (δ13CCH4) of emitted CH4. Enhanced microbial consumption of methane in the aerobic portion of the landfill cover is indicated by a shift to heavier (less depleted) isotopic values in the residual methane emitted to air. This study was conducted at four landfill sites in southwest England. Measurement of CH4 using a mobile vehicle mounted instrument at the four sites was coupled with Flexfoil bag sampling of ambient air for high-precision isotope analysis. Gas well collection systems were sampled to estimate landfill oxidised proportion. Closed or active status, seasonal variation, cap stripping and site closure impact on landfill isotopic signature were also assessed. The δ13CCH4 values ranged from -60 to -54‰, with an average value of -57 ± 2‰. Methane emissions from active cells are more depleted in 13C than closed sites. Methane oxidation, estimated from the isotope fractionation, ranged from 2.6 to 38.2%, with mean values of 9.5% for active and 16.2% for closed landfills, indicating that oxidised proportion is highly site specific.
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Affiliation(s)
- Semra Bakkaloglu
- Department of Earth Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK; Sustainable Gas Institute, Imperial College London, London SW7 1NA, UK.
| | - Dave Lowry
- Department of Earth Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - Rebecca E Fisher
- Department of Earth Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - James L France
- Department of Earth Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK; British Antarctic Survey, High Cross, Madingley Rd, Cambridge CB3 0ET, UK
| | - Euan G Nisbet
- Department of Earth Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
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9
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Manheim DC, Yeşiller N, Hanson JL. Gas Emissions from Municipal Solid Waste Landfills: A Comprehensive Review and Analysis of Global Data. J Indian Inst Sci 2021. [DOI: 10.1007/s41745-021-00234-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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10
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Zhan LT, Wu T, Feng S, Li GY, He HJ, Lan JW, Chen YM. Full-scale experimental study of methane emission in a loess-gravel capillary barrier cover under different seasons. WASTE MANAGEMENT (NEW YORK, N.Y.) 2020; 107:54-65. [PMID: 32276126 DOI: 10.1016/j.wasman.2020.03.026] [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: 06/05/2019] [Revised: 02/01/2020] [Accepted: 03/18/2020] [Indexed: 06/11/2023]
Abstract
The methane emission in a loess-gravel capillary barrier cover (CBC) in winter and summer was investigated by constructing a full-scale testing facility (20 m × 30 m) with a slope angle of 14.5° at a landfill in Xi'an, China. Weather conditions, methane emission, gas concentration, temperature, and volumetric water content (VWC) in the CBC were measured. The temperature and moisture in the CBC showed a typical seasonal pattern of warm and dry in summer and cold and wet in winter. Accordingly, the maximum methane oxidation rate and methane emission were higher in summer. The mean methane influx and methane emission decreased significantly as the VWC increased beyond 40% (i.e., a degree of saturation 0.85) at a depth of 0.85 m, which was near the loess/gravel interface. At this depth, more water was presented in the loess layer in the downslope direction due to capillary barrier effects, which increased the upslope methane emission. More dominant methane emission in the middle- and upper-section of the CBC occurred in summer than in winter as there was less soil moisture to facilitate methane transfer. The LFG balance showed that a significant fraction of the loaded LFG was not accounted in the flux chamber measurements due to the preferential flow along the edges of the CBC. The maximum methane oxidation rate was 93.3 g CH4 m-2 d-1, indicating the loess-gravel CBC could mitigate methane emissions after landfill closure.
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Affiliation(s)
- Liang-Tong Zhan
- MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Department of Civil Engineering, Zhejiang University, Hangzhou 310058, China
| | - Tao Wu
- MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Department of Civil Engineering, Zhejiang University, Hangzhou 310058, China
| | - Song Feng
- MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Department of Civil Engineering, Zhejiang University, Hangzhou 310058, China; College of Civil Engineering, Fuzhou University, China.
| | - Guang-Yao Li
- MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Department of Civil Engineering, Zhejiang University, Hangzhou 310058, China
| | - Hai-Jie He
- College of Civil and Architectural Engineering, Taizhou University, Taizhou 318000, China
| | - Ji-Wu Lan
- MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Department of Civil Engineering, Zhejiang University, Hangzhou 310058, China
| | - Yun-Min Chen
- MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Department of Civil Engineering, Zhejiang University, Hangzhou 310058, China
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11
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Parsaeifard N, Sattler M, Nasirian B, Chen VCP. Enhancing anaerobic oxidation of methane in municipal solid waste landfill cover soil. WASTE MANAGEMENT (NEW YORK, N.Y.) 2020; 106:44-54. [PMID: 32182561 DOI: 10.1016/j.wasman.2020.03.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 03/07/2020] [Accepted: 03/09/2020] [Indexed: 06/10/2023]
Abstract
Landfills are the third largest anthropogenic source of the greenhouse gas methane worldwide. In the upper portions of landfill covers, methane is oxidized aerobically by microorganisms to form the less-potent greenhouse gas carbon dioxide; however, because of the low permeability of oxygen, no aerobic oxidation occurs in deeper portions of the cover. Therefore, the goal of this study was to enhance anaerobic oxidation of methane (AOM) in the deeper parts of landfill covers, to increase overall methane removal, via addition of electron acceptors besides oxygen. In batch tests, landfill cover soil was amended using five alternate electron acceptors: iron(III), nitrate, nitrite, sulfate, and manganese. AOM was then measured via column tests, which included realistic conditions of gas flow, cover thickness, and compaction. In the batch tests, soils amended with nitrate, sulfate, and the combination of sulfate + hematite removed more methane compared to control soil. Methane generation inhibitor had no impact on net methane removal. Adding nutrients to the soil significantly enhanced methane removal only for the case of soil without electron acceptors. Greater methane removal was observed for reactors with higher initial methane concentration. Results of the column tests showed that soil amended with sulfate + iron had the highest (around 10%) removal of methane in the anoxic zone, followed by soil amended with sulfate. Hydrogen sulfide (H2S) gas was measured in the headspace of these two columns, which indicated that sulfate-reducing bacteria were likely responsible for methane removal.
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Affiliation(s)
- Niloofar Parsaeifard
- Department of Civil Engineering, University of Texas at Arlington, Box 19308, Arlington, TX 76019, United States.
| | - Melanie Sattler
- Department of Civil Engineering, University of Texas at Arlington, Box 19308, Arlington, TX 76019, United States
| | - Bahareh Nasirian
- Department of Industrial, Manufacturing, and Systems Engineering, University of Texas at Arlington, Box 19017, Arlington, TX 76019, United States
| | - Victoria C P Chen
- Department of Industrial, Manufacturing, and Systems Engineering, University of Texas at Arlington, Box 19017, Arlington, TX 76019, United States
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12
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Bian R, Shi W, Chai X, Sun Y. Effects of plant radial oxygen loss on methane oxidation in landfill cover soil: A simulative study. WASTE MANAGEMENT (NEW YORK, N.Y.) 2020; 102:56-64. [PMID: 31669675 DOI: 10.1016/j.wasman.2019.10.033] [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: 12/10/2018] [Revised: 10/15/2019] [Accepted: 10/16/2019] [Indexed: 06/10/2023]
Abstract
Radial oxygen loss (ROL) by the spreading root systems of vegetation can improve soil aeration for subsequent oxidation of methane (CH4) by microbes in landfill cover soils. This study proposes a theoretical model that elucidated the effects of ROL on microbial oxidation of CH4 to understand landfill gas transportation and oxidation in landfill cover soils. Parametric analyses were conducted to investigate the effects of root depth, root architecture, and ROL rate on the CH4 oxidation efficiency of landfill cover soils. The simulation results suggested that disregarding O2 emissions by plants root systems could underestimate the CH4 oxidation efficiency, especially when the water content ranged from 20% to 35%. Additionally, plants with a parabolic root architecture indicated 7-13% higher CH4 oxidation efficiency than other root architectures, i.e., uniform, triangular, and exponential. The CH4 oxidation efficiency increased rapidly at root depths less than 0.25 m. Therefore, plants characterized by a parabolic root architecture, longer root length, and higher ROL capacity should be selected as the preferred species for mitigating CH4 emissions from landfills in humid areas.
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Affiliation(s)
- Rongxing Bian
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China
| | - Wei Shi
- Xi'an Solid Waste Administration, Xi'an 710038, China
| | - Xiaoli Chai
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China.
| | - Yingjie Sun
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266033, China
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13
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Barometric-pumping controls fugitive gas emissions from a vadose zone natural gas release. Sci Rep 2019; 9:14080. [PMID: 31575969 PMCID: PMC6773692 DOI: 10.1038/s41598-019-50426-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 09/11/2019] [Indexed: 11/08/2022] Open
Abstract
Subsurface natural gas release from leaking oil and gas wells is a major environmental concern. Gas migration can cause aquifer contamination, explosive conditions in soil gas, and greenhouse gas emissions. Gas migration is controlled by complex interacting processes, thus constraining the distribution and magnitude of “fugitive gas” emissions remains a challenge. We simulated wellbore leakage in the vadose zone through a controlled release experiment and demonstrate that fugitive gas emissions can be directly influenced by barometric pressure changes. Decreases in barometric-pressure led to surface gas breakthroughs (>20-fold increase in <24 hours), even in the presence of low-permeability surficial soils. Current monitoring strategies do not consider the effect of barometric pressure changes on gas migration and may not provide adequate estimates of fugitive gas emissions. Frequent or continuous monitoring is needed to accurately detect and quantify fugitive gas emissions at oil and gas sites with a deep water table.
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Sparrow KJ, Chanton JP, Green RB, Scheutz C, Hater GR, Wilson LC, Abichou T. Stable isotopic determination of methane oxidation: When smaller scales are better. WASTE MANAGEMENT (NEW YORK, N.Y.) 2019; 97:82-87. [PMID: 31447030 DOI: 10.1016/j.wasman.2019.07.032] [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: 05/29/2019] [Revised: 07/20/2019] [Accepted: 07/22/2019] [Indexed: 06/10/2023]
Abstract
Stable isotope measurements are an effective tool for evaluating methane (CH4) consumption in landfill soils. However, determining the extent of CH4 oxidation in soils using this approach can be inherently biased, depending on characteristics of the study site and the sampling strategy that is employed. In this study, we establish the unusual case that sampling at smaller scales captures a better representation of the degree of oxidation occurring in landfill cover soils. We did this by comparing three techniques (Plume, Probe, and Transect) that vary in the location of sampling within a site and in the areal footprint of each sample. The Plume method yielded estimates of CH4 oxidation that were 13-16% lower than the Transect and Probe methods, respectively. The Probe and Transect methods, two relatively small-scale and high resolution methods, the latter of which has not been previously described, are best suited to quantify CH4 oxidation in landfill soils as they demonstrably overcome the tendency of stable isotope methods to underestimate CH4 oxidation at the landfill scale. We recommend the use of these two sampling methods for monitoring the efficacy of landfill CH4 reduction strategies that are desired to help meet the goals of the Paris Agreement.
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Affiliation(s)
- Katy J Sparrow
- Department of Earth, Ocean, and Atmospheric Science, Florida State University, 1017 Academic Way, Tallahassee, FL 32301, United States.
| | - Jeffrey P Chanton
- Department of Earth, Ocean, and Atmospheric Science, Florida State University, 1017 Academic Way, Tallahassee, FL 32301, United States.
| | - Roger B Green
- Waste Management, 4228 Airport Road, Cincinnati, OH 45226, United States
| | - Charlotte Scheutz
- Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Gary R Hater
- Waste Management, 4228 Airport Road, Cincinnati, OH 45226, United States
| | - L Claire Wilson
- Department of Earth, Ocean, and Atmospheric Science, Florida State University, 1017 Academic Way, Tallahassee, FL 32301, United States
| | - Tarek Abichou
- Department of Civil and Environmental Engineering, FAMU-FSU College of Engineering, 2525 Pottsdamer St, Tallahassee, FL 32310, United States
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Bian R, Xin D, Chai X. Methane emissions from landfill: influence of vegetation and weather conditions. ENVIRONMENTAL TECHNOLOGY 2019; 40:2173-2181. [PMID: 29421946 DOI: 10.1080/09593330.2018.1439109] [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: 11/17/2017] [Accepted: 02/06/2018] [Indexed: 06/08/2023]
Abstract
Vegetation plays an important role in CH4 transport and oxidation in landfill cover soil. This study investigated CH4 emission fluxes in two landfills with different surface coverage conditions and it found that the CH4 emission fluxes presented spatial and temporal disparities. A significant discrepancy in CH4 emission flux between day and night in areas covered with Kochia sieversiana indicated that enhanced diffusion induced by rising temperature was the main mechanism for CH4 transport during daytime. A significant increase of CH4 emission flux after the K. sieversiana and Suaeda glauca plants were cut indicated that these plants provide greater contributions to CH4 oxidation than to CH4 transport. Diel CH4 emission flux was found closely correlated with the climatic conditions. Diffusion was determined as the main mechanism for CH4 transport at daytime in bare area, mediated by solar radiation and air temperature. Diffusion and plant-mediated transport by convection was established as the main transport mechanism in areas covered with K. sieversiana. Our results further the understanding of both the CH4 emission mechanism and the impact of vegetation on CH4 oxidation, transport, and emission, which will benefit the development of a reliable model for landfill CH4 emissions.
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Affiliation(s)
- Rongxing Bian
- a State Key Laboratory of Pollution Control and Resource Reuse, Tongji University , Shanghai , People's Republic of China
| | - Danhui Xin
- a State Key Laboratory of Pollution Control and Resource Reuse, Tongji University , Shanghai , People's Republic of China
- b Department of Civil and Environmental Engineering, University of Delaware , Newark , DE , USA
| | - Xiaoli Chai
- a State Key Laboratory of Pollution Control and Resource Reuse, Tongji University , Shanghai , People's Republic of China
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Bian R, Shi W, Duan Y, Chai X. Effect of soil types and ammonia concentrations on the contribution of ammonia-oxidizing bacteria to CH 4 oxidation. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2019; 37:698-705. [PMID: 31023154 DOI: 10.1177/0734242x19843988] [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] [Indexed: 06/09/2023]
Abstract
Irrigation of stabilized landfill leachate to landfill cover soil is a cost-effective operation for leachate treatment. The contribution of ammonia-oxidizing bacteria (AOB) in the cover soil to CH4 oxidation, however, is unclear, because AOB and methane-oxidizing bacteria (MOB) can co-oxidize CH4 and NH4+-N. Thus, the contribution of AOB and the inhibitory effect of NH4+-N to CH4 oxidation were determined by using an acetylene pretreatment discrimination method. The results showed that the contributions of AOB to CH4 oxidation varied with the soil type and the concentration of NH4+-N addition. The relative contribution of AOB to CH4 oxidation for compost without NH4+-N addition was the highest (65.0%), and was 2.5 and 3.4 times higher than the corresponding values for aged refuse and landfill cover soil, respectively. The inhibitory effect of NH4+-N was enhanced by increasing the concentration of NH4+-N addition for all the soil samples. At equal NH4+-N addition concentrations, the inhibitory effect was always the lowest for the compost sample. The abundances of particulate methane monooxygenase (pmoA) and ammonia monooxygenase (amoA) genes were key factors influencing the CH4 oxidation rate and contribution of AOB to CH4 oxidation. The higher abundance of pmoA and lower abundance of amoA in landfill cover soil could explain the higher CH4 oxidation rate and lower contribution of AOB to CH4 oxidation in this soil type. Meanwhile, the higher contribution of AOB to CH4 oxidation for compost could be attributed to the higher abundance of the amoA gene and lower abundance of pmoA.
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Affiliation(s)
- Rongxing Bian
- 1 State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, China
| | - Wei Shi
- 2 Xi'an Solid Waste Administration, China
| | | | - Xiaoli Chai
- 1 State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, China
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17
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Morris JWF, Caldwell MD, Obereiner JM, O'Donnell ST, Johnson TR, Abichou T. Modeling methane oxidation in landfill cover soils as indicator of functional stability with respect to gas management. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2019; 69:13-22. [PMID: 30010508 DOI: 10.1080/10962247.2018.1500403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 04/27/2018] [Accepted: 07/10/2018] [Indexed: 06/08/2023]
Abstract
A performance-based method for evaluating methane (CH4) oxidation as the best available control technology (BACT) for passive management of landfill gas (LFG) was applied at a municipal solid waste (MSW) landfill in central Washington, USA, to predict when conditions for functional stability with respect to LFG management would be expected. The permitted final cover design at the subject landfill is an all-soil evapotranspirative (ET) cover system. Using a model, a correlation between CH4 loading flux and oxidation was developed for the specific ET cover design. Under Washington's regulations, a MSW landfill is functionally stable when it does not present a threat to human health or the environment (HHE) at the relevant point of exposure (POE), which was conservatively established as the cover surface. Approaches for modeling LFG migration and CH4 oxidation are discussed, along with comparisons between CH4 oxidation and biodegradation of non-CH4 organic compounds (NMOCs). The modeled oxidation capacity of the ET cover design is 15 g/m2/day under average climatic conditions at the site, with 100% oxidation expected on an annual average basis for fluxes up to 8 g/m2/day. This translates to a sitewide CH4 generation rate of about 260 m3/hr, which represents the functional stability target for allowing transition to cover oxidation as the BACT (subject to completion of a confirmation monitoring program). It is recognized that less than 100% oxidation might occur periodically if climate and/or cover conditions do not precisely match the model, but that residual emissions during such events would be de minimis in comparison with published limit values. Accordingly, it is also noted that nonzero net emissions may not represent a threat to HHE at a POE (i.e., a target flux between 8 and 15 g/m2/day might be appropriate for functional stability) depending on the site reuse plan and distance to potential receptors.Implications: This study provides a scientifically defensible method for estimating when methane oxidation in landfill cover soils may represent the best available control technology for residual landfill gas (LFG) emissions. This should help operators and regulators agree on the process of safely eliminating active LFG controls in favor of passive control measures once LFG generation exhibits asymptotic trend behavior below the oxidation capacity of the soil. It also helps illustrate the potential benefits of evolving landfill designs to include all-soil vegetated evapotranspirative (ET) covers that meet sustainability objectives as well as regulatory performance objectives for infiltration control.
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Affiliation(s)
| | | | | | | | | | - Tarek Abichou
- Department of Civil & Environmental Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL, USA
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18
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Harnessing fungi to mitigate CH 4 in natural and engineered systems. Appl Microbiol Biotechnol 2018; 102:7365-7375. [PMID: 29982927 DOI: 10.1007/s00253-018-9203-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 06/26/2018] [Accepted: 06/26/2018] [Indexed: 12/13/2022]
Abstract
Methane (CH4) is a powerful greenhouse gas emitted from natural and anthropogenic sources, and its emission rates vary among sources as a function of environment, microbial respiration, and feedbacks. Biological CH4 flux from natural and engineered systems is typically represented simply as generation of CH4 by methanogens minus oxidation by methanotrophs. In many cases, however, CH4 flux is modulated by transport and solubility mechanisms that occur before oxidation or other chemical transformation. The ability of fungi to directly oxidize CH4 remains unclear; however, their hydrophobic growths extending above microbial biofilms can improve surface area and sorption of hydrophobic gases. This can improve overall oxidation rates in a biofilm simply by improving phase transfer dynamics and bioavailability to bacterial or archaeal associates. This indirect facilitation is not necessarily intuitive, but there has been a recent emerging interest in harnessing these fungal abilities in engineering bioreactors and filtration systems designed to capture and oxidize CH4. These dynamics may be playing a similar facilitative role in natural CH4 oxidation, where fungi may indirectly influence carbon mineralization and methanogen/methanotroph communities, and/or directly oxidize and dissolve gaseous CH4. This review highlights these unique roles for fungi in determining net CH4 oxidation rates, and it summarizes the potential to harness fungi to mitigate CH4 emissions.
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19
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Bian R, Xin D, Chai X. A Simulation model for estimating methane oxidation and emission from landfill cover soils. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 77:426-434. [PMID: 29709311 DOI: 10.1016/j.wasman.2018.04.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 04/14/2018] [Accepted: 04/18/2018] [Indexed: 06/08/2023]
Abstract
Quantification of methane (CH4) oxidation and emission from landfill cover soils is important for evaluating measures to mitigate anthropogenic greenhouse gas emissions. In this study, a model that combines the multicomponent diffusive equation and Darcy's law, coupled with the dual Monod kinetic equation, was established to simulate CH4 transport, oxidation and emission in landfill cover soils. Sensitivity analysis was performed to illustrate the influence of model parameters on CH4 transport, oxidation and emission. The model was then applied to predict CH4 emissions from several column experiments. The results of the sensitivity analysis showed that a high CH4 oxidation rate can be obtained with a high Vmax of cover soil, even for a low cover soil thickness, and that oxidation efficiency is constant when the thickness of the cover soil becomes greater than a threshold value. The simulated results fitted well with the measured values, confirming that the new model provides a reliable method for estimating CH4 emissions from landfills.
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Affiliation(s)
- Rongxing Bian
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China
| | - Danhui Xin
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China; Department of Civil and Environmental Engineering, University of Delaware, Newark, DE 19716, United States
| | - Xiaoli Chai
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China.
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20
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O'Donnell ST, Caldwell MD, Barlaz MA, Morris JWF. Case study comparison of functional vs. organic stability approaches for assessing threat potential at closed landfills in the USA. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 75:415-426. [PMID: 29429871 DOI: 10.1016/j.wasman.2018.02.001] [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: 08/28/2017] [Revised: 01/31/2018] [Accepted: 02/01/2018] [Indexed: 06/08/2023]
Abstract
Municipal solid waste (MSW) landfills in the USA are regulated under Subtitle D of the Resource Conservation and Recovery Act (RCRA), which includes the requirement to protect human health and the environment (HHE) during the post-closure care (PCC) period. Several approaches have been published for assessment of potential threats to HHE. These approaches can be broadly divided into organic stabilization, which establishes an inert waste mass as the ultimate objective, and functional stability, which considers long-term emissions in the context of minimizing threats to HHE in the absence of active controls. The objective of this research was to conduct a case study evaluation of a closed MSW landfill using long-term data on landfill gas (LFG) production, leachate quality, site geology, and solids decomposition. Evaluations based on both functional and organic stability criteria were compared. The results showed that longer periods of LFG and leachate management would be required using organic stability criteria relative to an approach based on functional stability. These findings highlight the somewhat arbitrary and overly stringent nature of assigning universal stability criteria without due consideration of the landfill's hydrogeologic setting and potential environmental receptors. This supports previous studies that advocated for transition to a passive or inactive control stage based on a performance-based functional stability framework as a defensible mechanism for optimizing and ending regulatory PCC.
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Affiliation(s)
- Sean T O'Donnell
- Geosyntec Consultants, 10211 Wincopin Circle, 4th Floor, Columbia, MD 21044, USA.
| | - Michael D Caldwell
- Groundwater and Technical Programs, Waste Management, 3623 Wilson Road, Humble, TX 77396, USA.
| | - Morton A Barlaz
- Department of Civil, Construction, and Environmental Engineering, Campus Box 7908, North Carolina State University, Raleigh, NC 27695-7908, USA.
| | - Jeremy W F Morris
- Geosyntec Consultants, 1220 19th Street NW, Washington, D.C. 20036, USA.
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21
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Starostina V, Damgaard A, Eriksen MK, Christensen TH. Waste management in the Irkutsk region, Siberia, Russia: An environmental assessment of alternative development scenarios. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2018; 36:373-385. [PMID: 29475411 DOI: 10.1177/0734242x18757627] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The current waste management system, handling around 500,000 t of household, commercial, and institutional waste annually in the Irkutsk region, Siberia, is based on landfilling in an old landfill with no controls of leachate and gas. Life-cycle assessment modelling of the current system shows that it is a major load on the environment, while the simulation of seven alternative systems results in large savings in many impact categories. With respect to climate change, it is estimated that a saving of about 1200 kg CO2 equivalents is possible per year, per inhabitant, which is a significant reduction in greenhouse gas emissions. The best alternatives involve efficient energy recovery from waste and recycling by source separation for commercial and institutional waste, the major waste type in the Irkutsk region. Recycling of household waste seems less attractive, and it is therefore recommended only to consider this option after experience has been gained with the commercial and institutional waste. Sensitivity analysis shows that recovery of energy - in particular electricity, heat, and steam - from waste is crucial to the environmental performance of the waste management system. This relates to the efficiencies of energy recovery as well as what the recovered energy substitutes, that is, the 'dirtier' the off-set energy, the higher the environmental savings for the waste management system. Since recovered energy may be utilised by only a few energy grids or industrial users, it is recommended to perform additional local assessments of the integration of the waste energy into existing systems and facilities.
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Affiliation(s)
- Vlada Starostina
- 1 Department of Mineral Processing and Environmental Protection, Irkutsk National Research Technical University, Irkutsk, Russia
| | - Anders Damgaard
- 2 Department of Environmental Engineering, Technical University of Denmark, Lyngby, Denmark
| | - Marie K Eriksen
- 2 Department of Environmental Engineering, Technical University of Denmark, Lyngby, Denmark
| | - Thomas H Christensen
- 2 Department of Environmental Engineering, Technical University of Denmark, Lyngby, Denmark
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22
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Xing Z, Zhao T, Gao Y, He Z, Zhang L, Peng X, Song L. Real-time monitoring of methane oxidation in a simulated landfill cover soil and MiSeq pyrosequencing analysis of the related bacterial community structure. WASTE MANAGEMENT (NEW YORK, N.Y.) 2017; 68:369-377. [PMID: 28532620 DOI: 10.1016/j.wasman.2017.05.007] [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: 10/27/2016] [Revised: 04/30/2017] [Accepted: 05/03/2017] [Indexed: 06/07/2023]
Abstract
Real-time CH4 oxidation in a landfill cover soil was studied using automated gas sampling that determined biogas (CH4 and CO2) and O2 concentrations at various depths in a simulated landfill cover soil (SLCS) column reactor. The real-time monitoring system obtained more than 10,000 biogas (CH4 and CO2) and O2 data points covering 32 steady states of CH4 oxidation with 32 different CH4 fluxes (0.2-125mol·m-2·d-1). The kinetics of CH4 oxidation at different depths (0-20cm, 20-40cm, and 40-60cm) of SLCS were well fit by a CH4-O2 dual-substrate model based on 32 values (averaged, n=5-15) of equilibrated CH4 concentrations. The quality of the fit (R2 ranged from 0.90 to 0.96) was higher than those reported in previous studies, which suggests that real time monitoring is beneficial for CH4 oxidation simulations. MiSeq pyrosequencing indicated that CH4 flux events changed the bacterial community structure (e.g., increased the abundance of Bacteroidetes and Methanotrophs) and resulted in a relative increase in the amount of type I methanotrophs (Methylobacter and Methylococcales) and a decrease in the amount of type II methanotrophs (Methylocystis).
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Affiliation(s)
- Zhilin Xing
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China; Faculty of Urban Construction and Environment Engineering, Chongqing University, Chongqing 400045, China
| | - Tiantao Zhao
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China; Faculty of Urban Construction and Environment Engineering, Chongqing University, Chongqing 400045, China.
| | - Yanhui Gao
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China; Faculty of Urban Construction and Environment Engineering, Chongqing University, Chongqing 400045, China
| | - Zhi He
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China
| | - Lijie Zhang
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China
| | - Xuya Peng
- Faculty of Urban Construction and Environment Engineering, Chongqing University, Chongqing 400045, China
| | - Liyan Song
- Environmental Microbiology and Ecology Research Center, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Science (CAS), Chongqing 400714, China.
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Xing ZL, Zhao TT, Gao YH, Yang X, Liu S, Peng XY. Methane oxidation in a landfill cover soil reactor: Changing of kinetic parameters and microorganism community structure. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2017; 52:254-264. [PMID: 27901632 DOI: 10.1080/10934529.2016.1253394] [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] [Indexed: 06/06/2023]
Abstract
Changing of CH4 oxidation potential and biological characteristics with CH4 concentration was studied in a landfill cover soil reactor (LCSR). The maximum rate of CH4 oxidation reached 32.40 mol d-1 m-2 by providing sufficient O2 in the LCSR. The kinetic parameters of methane oxidation in landfill cover soil were obtained by fitting substrate diffusion and consumption model based on the concentration profile of CH4 and O2. The values of [Formula: see text] (0.93-2.29%) and [Formula: see text] (140-524 nmol kgsoil-DW-1·s-1) increased with CH4 concentration (9.25-20.30%), while the values of [Formula: see text] (312.9-2.6%) and [Formula: see text] (1.3 × 10-5 to 9.0 × 10-3 nmol mL-1 h-1) were just the opposite. MiSeq pyrosequencing data revealed that Methylobacter (the relative abundance was decreased with height of LCSR) and Methylococcales_unclassified (the relative abundance was increased expect in H 80) became the key players after incubation with increasing CH4 concentration. These findings provide information for assessing CH4 oxidation potential and changing of biological characteristics in landfill cover soil.
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Affiliation(s)
- Zhi L Xing
- a Faculty of Urban Construction and Environment Engineering, Chongqing University , Chongqing , China
- b School of Chemistry and Chemical Engineering, Chongqing University of Technology , Chongqing , China
| | - Tian T Zhao
- a Faculty of Urban Construction and Environment Engineering, Chongqing University , Chongqing , China
- b School of Chemistry and Chemical Engineering, Chongqing University of Technology , Chongqing , China
| | - Yan H Gao
- a Faculty of Urban Construction and Environment Engineering, Chongqing University , Chongqing , China
- b School of Chemistry and Chemical Engineering, Chongqing University of Technology , Chongqing , China
| | - Xu Yang
- b School of Chemistry and Chemical Engineering, Chongqing University of Technology , Chongqing , China
| | - Shuai Liu
- b School of Chemistry and Chemical Engineering, Chongqing University of Technology , Chongqing , China
| | - Xu Y Peng
- a Faculty of Urban Construction and Environment Engineering, Chongqing University , Chongqing , China
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Obulisamy PK, Sim Yan May J, Rajasekar B. Gradient packing bed bio-filter for landfill methane mitigation. BIORESOURCE TECHNOLOGY 2016; 217:205-209. [PMID: 26883060 DOI: 10.1016/j.biortech.2016.01.059] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 01/18/2016] [Accepted: 01/19/2016] [Indexed: 06/05/2023]
Abstract
We assessed the suitability of various biogenic materials for development of a gradient packed bed bio-filter to mitigate the methane (CH4) emission from landfills. Five different biogenic materials (windrow compost-WC; vermicompost-VC; landfill top cover-LTC; landfill bottom soil-LBS; and river soil sediment-SS) were screened. Among these materials, the VC showed a better CH4 oxidation potential (MOP) of 12.6μg CH4 gdw(-1)h(-1). Subsequently, the VC was used as a packing material along with wood chips in proto-type bio-filters. Wood chips were mixed at 5-15% to form three distinct gradients in a test bio-filter. Under the three different CH4 loading rates of 33, 44 and 55 gCH4 m(-3)h(-1), the achieved MOPs were 31, 41, and 47gCH4 m(-3)h(-1), respectively. The gradient packed bed bio-filter is effective for landfill CH4 mitigation than the conventional bio-filter as the latter shows gas channeling effects with poor MOPs.
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Affiliation(s)
- Parthiba Karthikeyan Obulisamy
- Sino-Forest Applied Research Centre for Pearl River Delta Environment (ARCPE), Department of Biology, Hong Kong Baptist University, Hong Kong, China; College of Marine and Environmental Sciences, James Cook University, Townsville, Queensland, Australia.
| | - Jane Sim Yan May
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore
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De la Cruz FB, Green RB, Hater GR, Chanton JP, Thoma ED, Harvey TA, Barlaz MA. Comparison of Field Measurements to Methane Emissions Models at a New Landfill. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:9432-9441. [PMID: 27455372 DOI: 10.1021/acs.est.6b00415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Estimates of methane emissions from landfills rely primarily on models due to both technical and economic limitations. While models are easy to implement, there is uncertainty due to the use of parameters that are difficult to validate. The objective of this research was to compare modeled emissions using several greenhouse gas (GHG) emissions reporting protocols including: (1) Intergovernmental Panel on Climate Change (IPCC); (2) U.S. Environmental Protection Agency Greenhouse Gas Reporting Program (EPA GHGRP); (3) California Air Resources Board (CARB); and (4) Solid Waste Industry for Climate Solutions (SWICS), with measured emissions data collected over three calendar years from a young landfill with no gas collection system. By working with whole landfill measurements of fugitive methane emissions and methane oxidation, the collection efficiency could be set to zero, thus eliminating one source of parameter uncertainty. The models consistently overestimated annual methane emissions by a factor ranging from 4-31. Varying input parameters over reasonable ranges reduced this range to 1.3-8. Waste age at the studied landfill was less than four years and the results suggest the need for measurements at additional landfills to evaluate the accuracy of the tested models to young landfills.
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Affiliation(s)
- Florentino B De la Cruz
- Department of Civil, Construction, and Environmental Engineering, Campus Box 7908, North Carolina State University , Raleigh, North Carolina 27695-7908, United States
| | - Roger B Green
- Waste Management, Inc., 2956 Montana Avenue, Cincinnati, Ohio 45211, United States
| | - Gary R Hater
- Waste Management, Inc., 2956 Montana Avenue, Cincinnati, Ohio 45211, United States
| | - Jeffrey P Chanton
- Department of Earth, Ocean, and Atmospheric Science, Florida State University , Tallahassee, Florida 32306, United States
| | - Eben D Thoma
- U.S. EPA, Office of Research and Development, National Risk Management Research Laboratory, Research Triangle Park, North Carolina 27711, United States
| | - Tierney A Harvey
- Department of Engineering and Physics, University of Central Oklahoma , Edmond, Oklahoma 73034, United States
| | - Morton A Barlaz
- Department of Civil, Construction, and Environmental Engineering, Campus Box 7908, North Carolina State University , Raleigh, North Carolina 27695-7908, United States
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Moreira JML, Candiani G. Assessment of methane generation, oxidation, and emission in a subtropical landfill test cell. ENVIRONMENTAL MONITORING AND ASSESSMENT 2016; 188:464. [PMID: 27406209 DOI: 10.1007/s10661-016-5460-7] [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: 04/03/2016] [Accepted: 06/27/2016] [Indexed: 06/06/2023]
Abstract
This paper presents results of a methane balance assessment in a test cell built in a region with a subtropical climate near São Paulo, Brazil. Measurements and calculations were carried out to obtain the total methane emission to the atmosphere, the methane oxidation rate in the cover, and the total methane generation rate in the test cell. The oxidation rate was obtained through a calculation scheme based on a vertical one-dimensional methane transport in the cover region. The measured maximum and mean methane fluxes to the atmosphere were 124.4 and 15.87 g m(-2) d(-1), respectively. The total methane generation rate obtained for the test cell was 0.0380 ± 0.0075 mol s(-1). The results yielded that 69 % of the emitted methane occurred through the central well and 31 % through the cover interface with the atmosphere. The evaluations of the methane oxidation fraction for localized conditions in the lateral embankment of the test cell yielded 0.36 ± 0.11, while for the whole test cell yielded 0.15 ± 0.10. These results conciliate localized and overall evaluations reported in the literature. The specific methane generation rate obtained for the municipal solid waste with an age of 410 days was 317 ± 62 mol year(-1) ton(-1). This result from the subtropical São Paulo region is lower than reported figures for tropical climates and higher than reported figures for temperate climates.
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Affiliation(s)
- João M L Moreira
- Centro de Engenharia, Modelagem e Ciências Sociais Aplicadas, Universidade Federal do ABC, Av. dos Estados 5001, Santo André, SP, 09210-580, Brazil.
| | - Giovano Candiani
- Departamento de Ciências Biológicas, Universidade Federal de São Paulo, Rua Antônio Doll de Moraes, 105, Diadema, SP, 09920-540, Brazil
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Bajar S, Singh A, Kaushik CP, Kaushik A. Evaluation and statistical optimization of methane oxidation using rice husk amended dumpsite soil as biocover. WASTE MANAGEMENT (NEW YORK, N.Y.) 2016; 53:136-143. [PMID: 26452424 DOI: 10.1016/j.wasman.2015.09.023] [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: 03/18/2015] [Revised: 09/16/2015] [Accepted: 09/17/2015] [Indexed: 06/05/2023]
Abstract
A laboratory scale study was conducted to investigate the effect of rice husk amended biocover to mitigate the CH4 emission from landfills. Various physico-chemical and environmental variables like proportion of amended biocover material (rice husk), temperature, moisture content, CH4 concentration, CO2 concentration, O2 concentration and incubation time were considered in the study which affect the CH4 bio-oxidation. For the present study, sequential statistical approach with Placket Burman Design (PBD) was used to identify significant variables, having influential role on CH4 bio-oxidation, from all variables. Further, interactive effect of four selected variables including rice husk proportion, temperature, CH4 concentration and incubation time was studied with Box-Behnken Design (BBD) adopting Response Surface Methodology (RSM) to optimize the conditions for CH4 oxidation. In this study, the maximum CH4 oxidation potential of 76.83μgCH4g(-1)dwh(-1) was observed under optimum conditions with rice husk amendment of 6% (w/w), 5h incubation time at 40°C temperature with 40% (v/v) initial CH4 concentration. The results for CH4 oxidation potential also advocated the suitability of rice husk amendment in biocover system to curb emitted CH4 from landfills/open dumpsite over conventional clay or sand cover on supplying CH4 and O2 to microbes on maintaining proper aeration.
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Affiliation(s)
- Somvir Bajar
- Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology, Hisar 125001, Haryana, India; School of Public Health, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India.
| | - Anita Singh
- Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology, Hisar 125001, Haryana, India; Department of Environmental Sciences, Central University of Jammu, Jammu & Kashmir 180011, India
| | - C P Kaushik
- Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology, Hisar 125001, Haryana, India
| | - Anubha Kaushik
- Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology, Hisar 125001, Haryana, India; University School of Environment Management, Guru Gobind Singh Indraprastha University, Dwarka, New Delhi 110075, India
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Qasaimeh A, Abdallah/Q MR, Hani FB. A Review on Biogas Interception Processes in Municipal Landfill. ACTA ACUST UNITED AC 2015. [DOI: 10.3923/jest.2016.1.25] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Sadasivam BY, Reddy KR. Adsorption and transport of methane in biochars derived from waste wood. WASTE MANAGEMENT (NEW YORK, N.Y.) 2015; 43:218-29. [PMID: 26005190 DOI: 10.1016/j.wasman.2015.04.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 03/21/2015] [Accepted: 04/21/2015] [Indexed: 05/16/2023]
Abstract
Mitigation of landfill gas (LFG) is among the critical aspects considered in the design of a landfill cover in order to prevent atmospheric pollution and control global warming. In general, landfill cover soils can partially remove methane (CH4) through microbial oxidation carried out by methanotrophic bacteria present within them. The oxidizing capacity of these landfill cover soils may be improved by adding organic materials, such as biochar, which increase adsorption and promote subsequent or simultaneous oxidation of CH4. In this study, seven wood-derived biochars and granular activated carbon (GAC) were characterized for their CH4 adsorption capacity by conducting batch and small-scale column studies. The effects of influential factors, such as exposed CH4 concentration, moisture content and temperature on CH4 adsorption onto biochars, were determined. The CH4 transport was modeled using a 1-D advection-dispersion equation that accounted for sorption. The effects of LFG inflow rates and moisture content on the combined adsorption and transport properties of biochars were determined. The maximum CH4 adsorption capacity of GAC (3.21mol/kg) was significantly higher than that of the biochars (0.05-0.9mol/kg). The CH4 gas dispersion coefficients for all of the biochars ranged from 1×10(-3) to 3×10(-3)m(2)s(-1). The presence of moisture significantly suppressed the extent of methane adsorption onto the biochars and caused the methane to break through within shorter periods of time. Overall, certain biochar types have a high potential to enhance CH4 adsorption and transport properties when used as a cover material in landfills. However, field-scale studies need to be conducted in order to evaluate the performance of biochar-based cover system under a more dynamic field condition that captures the effect of seasonal and temporal changes.
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Affiliation(s)
- Bala Yamini Sadasivam
- University of Illinois at Chicago, Department of Civil and Materials Engineering, 842 West Taylor Street, Chicago, IL 60607, USA.
| | - Krishna R Reddy
- University of Illinois at Chicago, Department of Civil and Materials Engineering, 842 West Taylor Street, Chicago, IL 60607, USA.
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Abichou T, Kormi T, Yuan L, Johnson T, Francisco E. Modeling the effects of vegetation on methane oxidation and emissions through soil landfill final covers across different climates. WASTE MANAGEMENT (NEW YORK, N.Y.) 2015; 36:230-240. [PMID: 25475118 DOI: 10.1016/j.wasman.2014.11.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 10/24/2014] [Accepted: 11/03/2014] [Indexed: 06/04/2023]
Abstract
Plant roots are reported to enhance the aeration of soil by creating secondary macropores which improve the diffusion of oxygen into soil as well as the supply of methane to bacteria. Therefore, methane oxidation can be improved considerably by the soil structuring processes of vegetation, along with the increase of organic biomass in the soil associated with plant roots. This study consisted of using a numerical model that combines flow of water and heat with gas transport and oxidation in soils, to simulate methane emission and oxidation through simulated vegetated and non-vegetated landfill covers under different climatic conditions. Different simulations were performed using different methane loading flux (5-200 g m(-2) d(-1)) as the bottom boundary. The lowest modeled surface emissions were always obtained with vegetated soil covers for all simulated climates. The largest differences in simulated surface emissions between the vegetated and non-vegetated scenarios occur during the growing season. Higher average yearly percent oxidation was obtained in simulations with vegetated soil covers as compared to non-vegetated scenario. The modeled effects of vegetation on methane surface emissions and percent oxidation were attributed to two separate mechanisms: (1) increase in methane oxidation associated with the change of the physical properties of the upper vegetative layer and (2) increase in organic matter associated with vegetated soil layers. Finally, correlations between percent oxidation and methane loading into simulated vegetated and non-vegetated covers were proposed to allow decision makers to compare vegetated versus non-vegetated soil landfill covers. These results were obtained using a modeling study with several simplifying assumptions that do not capture the complexities of vegetated soils under field conditions.
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Affiliation(s)
- Tarek Abichou
- Dept of Civil and Environmental Engineering, Florida State University, 2525 Pottsdamer Street, Tallahassee, FL 32311, USA.
| | - Tarek Kormi
- Ecole Nationale d'Ingénieurs de Gabès, University of Gabès, Rue Omar Ibn-Elkhattab 6029, Gabès, Tunisia; LASMAP, Ecole Polytechnique de Tunisie, University of Carthage, B.P. 743, La Marsa 2078, Tunisia
| | - Lei Yuan
- Geosyntec Consultants, Columbia, MD 21046, USA
| | | | - Escobar Francisco
- Dept of Civil and Environmental Engineering, Florida State University, 2525 Pottsdamer Street, Tallahassee, FL 32311, USA
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Henneberger R, Chiri E, Bodelier PEL, Frenzel P, Lüke C, Schroth MH. Field-scale tracking of active methane-oxidizing communities in a landfill cover soil reveals spatial and seasonal variability. Environ Microbiol 2014; 17:1721-37. [PMID: 25186436 DOI: 10.1111/1462-2920.12617] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 08/31/2014] [Indexed: 01/11/2023]
Abstract
Aerobic methane-oxidizing bacteria (MOB) in soils mitigate methane (CH4 ) emissions. We assessed spatial and seasonal differences in active MOB communities in a landfill cover soil characterized by highly variable environmental conditions. Field-based measurements of CH4 oxidation activity and stable-isotope probing of polar lipid-derived fatty acids (PLFA-SIP) were complemented by microarray analysis of pmoA genes and transcripts, linking diversity and function at the field scale. In situ CH4 oxidation rates varied between sites and were generally one order of magnitude lower in winter compared with summer. Results from PLFA-SIP and pmoA transcripts were largely congruent, revealing distinct spatial and seasonal clustering. Overall, active MOB communities were highly diverse. Type Ia MOB, specifically Methylomonas and Methylobacter, were key drivers for CH4 oxidation, particularly at a high-activity site. Type II MOB were mainly active at a site showing substantial fluctuations in CH4 loading and soil moisture content. Notably, Upland Soil Cluster-gamma-related pmoA transcripts were also detected, indicating concurrent oxidation of atmospheric CH4 . Spatial separation was less distinct in winter, with Methylobacter and uncultured MOB mediating CH4 oxidation. We propose that high diversity of active MOB communities in this soil is promoted by high variability in environmental conditions, facilitating substantial removal of CH4 generated in the waste body.
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Affiliation(s)
- Ruth Henneberger
- Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, 8092, Zurich, Switzerland
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32
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Lizik W, Im J, Semrau JD, Barcelona MJ. A field trial of nutrient stimulation of methanotrophs to reduce greenhouse gas emissions from landfill cover soils. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2013; 63:300-309. [PMID: 23556240 DOI: 10.1080/10962247.2012.755137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
UNLABELLED Landfills are among the major sources of anthropogenic methane (CH4) estimated to reach 40 x 10(9) kg per year worldwide by 2015 (IPCC, 2007). A 2 1/2-year field experiment was conducted at a closed landfill in western Michigan where methanotrophs, methane-consuming bacteria, were stimulated by nutrient addition to the soil without significantly increasing biogenic nitrous oxide (N2O) production. The effects of the nitrogen amendments (KNO3 and NH4Cl), phenylacetylene (a selective inhibitor of nitrifying bacteria that contribute to N2O production), and a canopy (to reduce direct water infiltration) on the vertical soil gas profiles of CH4, CO2, and O2 were measured in the top meter of the soil. Methane and nitrous oxide fluxes were calculated from the corresponding soil gas concentration gradients with respect to depth and a Millington-Quirk diffusivity coefficient in soil derived empirically from soil porosity, water content, and diffusivity coefficients in air from the literature. Methane flux estimates were as high as 218.4 g m(-2) day(-1) in the fall and 12.8 g/m(-2) day(-1) in the summer. During the spring and summer CH4 fluxes were reduced by more than half by adding KNO3 and NH4Cl into the soil as compared to control plots, while N2O fluxes increased substantially. The concurrent addition of phenylacetylene to the amendment decreased peak N2O production by half and the rate of peak methane oxidation by about one-third. The seasonal average methane and N2O flux data were extrapolated to estimate the reduction of CH4 and N2O fluxes into the atmosphere by nitrogen and inhibitor addition to the cover soils. The results suggest that such additions coupled with soil moisture management may provide a potential strategy to significantly reduce greenhouse gas emissions from landfills. IMPLICATIONS The results of a 2 1/2-year study of effects of nutrient stimulation on methane oxidation in landfill cover soils demonstrates that nutrient addition does decrease methane emissions. The work further underscores the control which soil moisture exerts on methane oxidation. Water management is critical to the success of methane oxidation strategies.
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Affiliation(s)
- William Lizik
- US. Defense Logistics Agency, Richmond, Virginia, USA
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33
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Morris JWF, Crest M, Barlaz MA, Spokas KA, Kerman A, Yuan L. Improved methodology to assess modification and completion of landfill gas management in the aftercare period. WASTE MANAGEMENT (NEW YORK, N.Y.) 2012; 32:2364-2373. [PMID: 22884579 DOI: 10.1016/j.wasman.2012.07.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 07/06/2012] [Accepted: 07/12/2012] [Indexed: 06/01/2023]
Abstract
Municipal solid waste landfills represent the dominant option for waste disposal in many parts of the world. While some countries have greatly reduced their reliance on landfills, there remain thousands of landfills that require aftercare. The development of cost-effective strategies for landfill aftercare is in society's interest to protect human health and the environment and to prevent the emergence of landfills with exhausted aftercare funding. The Evaluation of Post-Closure Care (EPCC) methodology is a performance-based approach in which landfill performance is assessed in four modules including leachate, gas, groundwater, and final cover. In the methodology, the objective is to evaluate landfill performance to determine when aftercare monitoring and maintenance can be reduced or possibly eliminated. This study presents an improved gas module for the methodology. While the original version of the module focused narrowly on regulatory requirements for control of methane migration, the improved gas module also considers best available control technology for landfill gas in terms of greenhouse gas emissions, air quality, and emissions of odoriferous compounds. The improved module emphasizes the reduction or elimination of fugitive methane by considering the methane oxidation capacity of the cover system. The module also allows for the installation of biologically active covers or other features designed to enhance methane oxidation. A methane emissions model, CALMIM, was used to assist with an assessment of the methane oxidation capacity of landfill covers.
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Affiliation(s)
- Jeremy W F Morris
- Geosyntec Consultants, 10220 Old Columbia Road, Suite A, Columbia, MD 21046, USA.
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34
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Widory D, Proust E, Bellenfant G, Bour O. Assessing methane oxidation under landfill covers and its contribution to the above atmospheric CO₂ levels: the added value of the isotope (δ¹³C and δ¹⁸O CO₂; δ¹³C and δD CH₄) approach. WASTE MANAGEMENT (NEW YORK, N.Y.) 2012; 32:1685-1692. [PMID: 22608681 DOI: 10.1016/j.wasman.2012.04.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 04/04/2012] [Accepted: 04/16/2012] [Indexed: 06/01/2023]
Abstract
We are presenting here a multi-isotope approach (δ¹³C and δ¹⁸O of CO₂; δ¹³C and δD of CH₄) to assess (i) the level(s) of methane oxidation during waste biodegradation and its migration through a landfill cover in Sonzay (France), and (ii) its contribution to the atmospheric CO₂ levels above the surface. The isotope approach is compared to the more conventional mass balance approach. Results from the two techniques are comparable and show that the CH₄ oxidation under the landfill cover is heterogenous, with low oxidation percentages in samples showing high biogas fluxes, which was expected in clay covers presenting fissures, through which CH₄ is rapidly transported. At shallow depth, more immobile biogas pockets show a higher level of CH₄ oxidation by the methanotrophic bacteria. δ¹³C of CO₂ samples taken at different heights (from below the cover up to 8m above the ground level) were also used to identify and assess the relative contributions of its main sources both under the landfill cover and in the surrounding atmosphere.
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Affiliation(s)
- D Widory
- BRGM, 3 ave Claude Guillemin, 45000 Orléans, France.
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35
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Laner D, Fellner J, Brunner PH. Site-specific criteria for the completion of landfill aftercare. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2012; 30:88-99. [PMID: 22993138 DOI: 10.1177/0734242x12453610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Municipal solid waste (MSW) landfills need to be managed after closure to assure long-term environmental compatibility. Aftercare can be completed when the authorities consider the landfill not likely to pose a threat to humans and the environment. In this work, a methodology for deriving site-specific aftercare completion criteria is presented and its application is illustrated via a case study. The evaluation method combines models addressing waste emission behavior, long-term barrier performance, and pollutant migration to assess the potential impact of landfill emissions on the environment. Based on the definition of acceptable impact levels at certain points of compliance, scenario- and pollutant-specific aftercare completion criteria are derived. The methodology was applied to a closed MSW landfill in Austria and potential aftercare durations were determined. While landfill gas emissions may become environmentally tolerable within decades at the site, leachate-related aftercare measures were expected to be necessary for centuries (primarily as a result of ammonium). Although the evaluation comes with large uncertainties, it allows for linking aftercare intensity and duration with respect to an environmentally compatible state of the landfill in the absence of aftercare. However, further case studies including regulatory review and acceptance are needed to use the methodology in a decision support tool on aftercare completion.
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Affiliation(s)
- David Laner
- Institute for Water Quality, Resource and Waste Management, Vienna University of Technology, Vienna, Austria.
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Schroth MH, Eugster W, Gómez KE, Gonzalez-Gil G, Niklaus PA, Oester P. Above- and below-ground methane fluxes and methanotrophic activity in a landfill-cover soil. WASTE MANAGEMENT (NEW YORK, N.Y.) 2012; 32:879-889. [PMID: 22143049 DOI: 10.1016/j.wasman.2011.11.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 10/28/2011] [Accepted: 11/08/2011] [Indexed: 05/31/2023]
Abstract
Landfills are a major anthropogenic source of the greenhouse gas methane (CH(4)). However, much of the CH(4) produced during the anaerobic degradation of organic waste is consumed by methanotrophic microorganisms during passage through the landfill-cover soil. On a section of a closed landfill near Liestal, Switzerland, we performed experiments to compare CH(4) fluxes obtained by different methods at or above the cover-soil surface with below-ground fluxes, and to link methanotrophic activity to estimates of CH(4) ingress (loading) from the waste body at selected locations. Fluxes of CH(4) into or out of the cover soil were quantified by eddy-covariance and static flux-chamber measurements. In addition, CH(4) concentrations at the soil surface were monitored using a field-portable FID detector. Near-surface CH(4) fluxes and CH(4) loading were estimated from soil-gas concentration profiles in conjunction with radon measurements, and gas push-pull tests (GPPTs) were performed to quantify rates of microbial CH(4) oxidation. Eddy-covariance measurements yielded by far the largest and probably most representative estimates of overall CH(4) emissions from the test section (daily mean up to ∼91,500μmolm(-2)d(-1)), whereas flux-chamber measurements and CH(4) concentration profiles indicated that at the majority of locations the cover soil was a net sink for atmospheric CH(4) (uptake up to -380μmolm(-2)d(-1)) during the experimental period. Methane concentration profiles also indicated strong variability in CH(4) loading over short distances in the cover soil, while potential methanotrophic activity derived from GPPTs was high (v(max)∼13mmolL(-1)(soil air)h(-1)) at a location with substantial CH(4) loading. Our results provide a basis to assess spatial and temporal variability of CH(4) dynamics in the complex terrain of a landfill-cover soil.
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Affiliation(s)
- M H Schroth
- Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, Universitätstrasse 16, 8092 Zürich, Switzerland.
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Response of Community Structure and Activity of Methanotroph to Different CH4/O2 Ratios. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.proenv.2012.10.096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Spokas K, Bogner J, Chanton J. A process-based inventory model for landfill CH4emissions inclusive of seasonal soil microclimate and CH4oxidation. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011jg001741] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Levis JW, Barlaz MA. Is biodegradability a desirable attribute for discarded solid waste? Perspectives from a national landfill greenhouse gas inventory model. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:5470-5476. [PMID: 21615182 DOI: 10.1021/es200721s] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
There is increasing interest in the use of biodegradable materials because they are believed to be "greener". In a landfill, these materials degrade anaerobically to form methane and carbon dioxide. The fraction of the methane that is collected can be utilized as an energy source and the fraction of the biogenic carbon that does not decompose is stored in the landfill. A landfill life-cycle model was developed to represent the behavior of MSW components and new materials disposed in a landfill representative of the U.S. average with respect to gas collection and utilization over a range of environmental conditions (i.e., arid, moderate wet, and bioreactor). The behavior of materials that biodegrade at relatively fast (food waste), medium (biodegradable polymer) and slow (newsprint and office paper) rates was studied. Poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) (PHBO) was selected as illustrative for an emerging biodegradable polymer. Global warming potentials (GWP) of 26, 720, -1000, 990, and 1300 kg CO(2)e wet Mg(-1) were estimated for MSW, food waste, newsprint, office paper, and PHBO, respectively in a national average landfill. In a state-of-the-art landfill with gas collection and electricity generation, GWP's of -250, 330, -1400, -96, and -420 kg CO(2)e wet Mg(-1) were estimated for MSW, food waste, newsprint, office paper and PHBO, respectively. Additional simulations showed that for a hypothetical material, a slower biodegradation rate and a lower extent of biodegradation improve the environmental performance of a material in a landfill representative of national average conditions.
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Affiliation(s)
- James W Levis
- Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Campus Box 7908, Raleigh, North Carolina 27695-7908, United States.
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