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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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Verma G, Chetri JK, Reddy KR. Evaluating the efficacy of biogeochemical cover system in mitigating landfill gas emissions: A large-scale laboratory simulation. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024:10.1007/s11356-024-34558-2. [PMID: 39098970 DOI: 10.1007/s11356-024-34558-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 07/26/2024] [Indexed: 08/06/2024]
Abstract
Municipal solid waste (MSW) landfills are a significant source of methane (CH4) emissions in the United States, contributing to global warming. Current landfill gas (LFG) management methods, like the landfill cover system and LFG collection system, do not entirely prevent LFG release. Biocovers have the potential to reduce CH4 emissions through microbial oxidation. However, LFG also contains carbon dioxide (CO2) and trace hydrogen sulfide (H2S) depending on waste composition, temperature, moisture content, and age of waste. An innovative biogeochemical cover (BGCC) was developed to tackle these concerns. This cover comprises a biochar-based biocover layer overlaid with a basic oxygen furnace (BOF) steel slag layer. The biochar-based biocover layer oxidizes CH4 emissions, while the BOF slag layer reduces CO2 and H2S through carbonation and sulfidation reaction mechanisms. The BGCC system's field performance remains unexamined. Therefore, a large-scale tank setup simulating near-field conditions was developed to evaluate the BGCC system's ability to mitigate CH4, CO2, and H2S from LFG simultaneously. Synthetic LFG was passed through the BGCC in five distinct phases, each designed to simulate the varying gas compositions and flux rates typical of MSW landfill. Gas profiles along the depth were monitored during each phase, and gas removal efficiency was measured. After testing, biocover and BOF slag samples were extracted to analyze physico-chemical properties. Batch tests were also conducted on samples extracted from the biocover and BOF slag layers to determine potential CH4 oxidation rates and residual CO2 sequestration capacity. The results showed that the BGCC system's CH4 removal efficiency decreased with higher CH4 flux rates, achieving its highest removal (74.7-79.7%) at moderate influx rates (23.9-25.5 g CH4/m2-day) and reducing to its lowest removal (27.4%) at the highest influx rate (57.5 g CH4/m2-day). Complete H2S removal occurred during Phase 3 in the biocover layer of BGCC system. CH4 oxidation rates were highest near the upper (277.9 µg CH4/g-day) and lowest in the deeper region of the biocover layer. In the tank experiment, CO2 breakthrough occurred after 156 days due to drying of the BOF slag layer, with an average residual carbonation capacity of 46 gCO2/kg slag after moisture adjustment. Overall, the BGCC system effectively mitigated LFG emissions, including CH4, CO2, and H2S, at moderate flux rates, showing promise as a comprehensive solution for LFG management.
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Affiliation(s)
- Gaurav Verma
- Department of Civil, Materials, and Environmental Engineering, University of Illinois Chicago, 842 West Taylor Street, Chicago, IL, 60607, USA
| | - Jyoti K Chetri
- Department of Civil, Materials, and Environmental Engineering, University of Illinois Chicago, 842 West Taylor Street, Chicago, IL, 60607, USA
| | - Krishna R Reddy
- Department of Civil, Materials, and Environmental Engineering, University of Illinois Chicago, 842 West Taylor Street, Chicago, IL, 60607, USA.
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Verma G, Chetri JK, Reddy KR. Spatial variation of methane oxidation and carbon dioxide sequestration in landfill biogeochemical cover. ENVIRONMENTAL TECHNOLOGY 2024:1-17. [PMID: 38955503 DOI: 10.1080/09593330.2024.2372052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 04/25/2024] [Indexed: 07/04/2024]
Abstract
The study investigated the spatial variation of potential methane (CH4) oxidation and residual carbon dioxide (CO2) sequestration in biogeochemical cover (BGCC) system designed to remove CH4, CO2, and hydrogen sulfide (H2S) from landfill gas (LFG) emissions. A 50 cm x 50 cm x 100 cm tank simulated BGCC system, comprising a biochar-amended soil (BAS) layer for CH4 oxidation, a basic oxygen furnace (BOF) slag layer for CO2 and H2S sequestration, and an upper topsoil layer. Synthetic LFG was flushed through the system in five phases, with each corresponding to different compositions and flow rates. Following monitoring, the system was dismantled, and samples were extracted from different depths and locations to analyze spatial variations, focusing on moisture content (MC), organic content (OC), pH, and electrical conductivity (EC). Additionally, batch tests on selected samples from BAS and BOF slag layers were performed to assess potential CH4 oxidation and residual carbonation capacity. The aim of study was to evaluate the BGCC's effectiveness in LFG mitigation, however this study focused on assessing spatial variations in physico-chemical properties, CH4 oxidation in the BAS layer, and residual carbonation in the BOF slag layer. Findings revealed CH4 oxidation in the BAS layer varied between 22.4 and 277.9 µg CH4/g-day, with higher rates in the upper part, and significant spatial variations at 50 cm below ground surface (bgs) compared to 85 cm bgs. The BOF slag layer showed a residual carbonation capacity of 40-49.3 g CO2/kg slag, indicating non-uniform carbonation. Overall, CH4 oxidation and CO2 sequestration capacities varied spatially and with depth in the BGCC system.
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Affiliation(s)
- Gaurav Verma
- Department of Civil, Materials, and Environmental Engineering, University of Illinois Chicago, Chicago, IL, USA
| | - Jyoti K Chetri
- Department of Civil, Materials, and Environmental Engineering, University of Illinois Chicago, Chicago, IL, USA
| | - Krishna R Reddy
- Department of Civil, Materials, and Environmental Engineering, University of Illinois Chicago, Chicago, IL, USA
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Brilli L, Toscano P, Carotenuto F, Di Lonardo S, Di Tommasi P, Magliulo V, Manco A, Vitale L, Zaldei A, Gioli B. Long-term investigation of methane and carbon dioxide emissions in two Italian landfills. Heliyon 2024; 10:e29356. [PMID: 38644898 PMCID: PMC11033122 DOI: 10.1016/j.heliyon.2024.e29356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 04/04/2024] [Accepted: 04/05/2024] [Indexed: 04/23/2024] Open
Abstract
Landfills play a key role as greenhouse gas (GHGs) emitters, and urgently need assessment and management plans development to swiftly reduce their climate impact. In this context, accurate emission measurements from landfills under different climate and management would reduce the uncertainty in emission accounting. In this study, more than one year of long-term high-frequency data of CO2 and CH4 fluxes were collected in two Italian landfills (Giugliano and Case Passerini) with contrasting management (gas recovery VS no management) using eddy covariance (EC), with the aim to i) investigate the relation between climate drivers and CO2 and CH4 fluxes at different time intervals and ii) to assess the overall GHG balances including the biogas extraction and energy recovery components. Results indicated a higher net atmospheric CO2 source (5.7 ± 5.3 g m2 d-1) at Giugliano compared to Case Passerini (2.4 ± 4.9 g m2 d-1) as well as one order of magnitude higher atmospheric CH4 fluxes (6.0 ± 5.7 g m2 d-1 and 0.7 ± 0.6 g m2 d-1 respectively). Statistical analysis highlighted that fluxes were mainly driven by thermal variables, followed by water availability, with their relative importance changing according to the time-interval considered. The rate of change in barometric pressure (dP/dt) influenced CH4 patterns and magnitude in the classes ranging from -1.25 to +1.25 Pa h-1, with reduction when dP/dt > 0 and increase when dP/dt < 0, whilst a clear pattern was not observed when all dP/dt classes were analyzed. When including management, the total atmospheric GHG balance computed for the two landfills of Giugliano and Case Passerini was 174 g m2 d-1 and 79 g m2 d-1 respectively, of which 168 g m2 d-1 and 20 g m2 d-1 constituted by CH4 fluxes.
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Affiliation(s)
- L. Brilli
- National Research Council of Italy, Institute of BioEconomy (CNR-IBE), Firenze, 50145, Italy
| | - P. Toscano
- National Research Council of Italy, Institute of BioEconomy (CNR-IBE), Firenze, 50145, Italy
| | - F. Carotenuto
- National Research Council of Italy, Institute of BioEconomy (CNR-IBE), Firenze, 50145, Italy
| | - S. Di Lonardo
- National Research Council of Italy, Research Institute on Terrestrial Ecosystems (CNR-IRET), Sesto Fiorentino, 50019, Florence, Italy
| | - P. Di Tommasi
- National Research Council of Italy, Institute for Agricultural and Forest Systems in the Mediterranean (CNR-ISAFOM), Ercolano, 80056, Naples, Italy
| | - V. Magliulo
- National Research Council of Italy, Institute for Agricultural and Forest Systems in the Mediterranean (CNR-ISAFOM), Ercolano, 80056, Naples, Italy
| | - A. Manco
- National Research Council of Italy, Institute for Agricultural and Forest Systems in the Mediterranean (CNR-ISAFOM), Ercolano, 80056, Naples, Italy
| | - L. Vitale
- National Research Council of Italy, Institute for Agricultural and Forest Systems in the Mediterranean (CNR-ISAFOM), Ercolano, 80056, Naples, Italy
| | - A. Zaldei
- National Research Council of Italy, Institute of BioEconomy (CNR-IBE), Firenze, 50145, Italy
| | - B. Gioli
- National Research Council of Italy, Institute of BioEconomy (CNR-IBE), Firenze, 50145, Italy
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Dhiman S, Khanna K, Kour J, Singh AD, Bhardwaj T, Devi K, Sharma N, Kumar V, Bhardwaj R. Landfill bacteriology: Role in waste bioprocessing elevated landfill gaseselimination and heat management. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 354:120364. [PMID: 38387351 DOI: 10.1016/j.jenvman.2024.120364] [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: 09/01/2023] [Revised: 01/10/2024] [Accepted: 02/08/2024] [Indexed: 02/24/2024]
Abstract
This study delves into the critical role of microbial ecosystems in landfills, which are pivotal for handling municipal solid waste (MSW). Within these landfills, a complex interplay of several microorganisms (aerobic/anaerobic bacteria, archaea or methanotrophs), drives the conversion of complex substrates into simplified compounds and complete mineralization into the water, inorganic salts, and gases, including biofuel methane gas. These landfills have dominant biotic and abiotic environments where various bacterial, archaeal, and fungal groups evolve and interact to decompose substrate by enabling hydrolytic, fermentative, and methanogenic processes. Each landfill consists of diverse bio-geochemical environments with complex microbial populations, ranging from deeply underground anaerobic methanogenic systems to near-surface aerobic systems. These kinds of landfill generate leachates which in turn emerged as a significant risk to the surrounding because generated leachates are rich in toxic organic/inorganic components, heavy metals, minerals, ammonia and xenobiotics. In addition to this, microbial communities in a landfill ecosystem could not be accurately identified using lab microbial-culturing methods alone because most of the landfill's microorganisms cannot grow on a culture medium. Due to these reasons, research on landfills microbiome has flourished which has been characterized by a change from a culture-dependent approach to a more sophisticated use of molecular techniques like Sanger Sequencing and Next-Generation Sequencing (NGS). These sequencing techniques have completely revolutionized the identification and analysis of these diverse microbial communities. This review underscores the significance of microbial functions in waste decomposition, gas management, and heat control in landfills. It further explores how modern sequencing technologies have transformed our approach to studying these complex ecosystems, offering deeper insights into their taxonomic composition and functionality.
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Affiliation(s)
- Shalini Dhiman
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University Amritsar, 143005, Punjab, India
| | - Kanika Khanna
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University Amritsar, 143005, Punjab, India; Department of Microbiology, DAV University, Sarmastpur, Jalandhar, 144001, Punjab, India
| | - Jaspreet Kour
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University Amritsar, 143005, Punjab, India
| | - Arun Dev Singh
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University Amritsar, 143005, Punjab, India
| | - Tamanna Bhardwaj
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University Amritsar, 143005, Punjab, India
| | - Kamini Devi
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University Amritsar, 143005, Punjab, India
| | - Neerja Sharma
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University Amritsar, 143005, Punjab, India
| | - Vinod Kumar
- Department of Botany, Government College for Women, Gandhi Nagar, Jammu 180004, Jammu & Kashmir, India.
| | - Renu Bhardwaj
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University Amritsar, 143005, Punjab, India
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Mondal T, Choudhury M, Kundu D, Dutta D, Samanta P. Landfill: An eclectic review on structure, reactions and remediation approach. WASTE MANAGEMENT (NEW YORK, N.Y.) 2023; 164:127-142. [PMID: 37054538 DOI: 10.1016/j.wasman.2023.03.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 02/14/2023] [Accepted: 03/24/2023] [Indexed: 06/19/2023]
Abstract
Since the enactment of the Clean Water Act (1972), which was supplemented by increased accountability under Resource Conservation and Recovery Act (RCRA) Subtitle D (1991) and the Clean Air Act Amendments (1996), landfills have indeed been widely used all around the world for treating various wastes. The landfill's biological and biogeochemical processes are believed to be originated about 2 to 4 decades ago. Scopus and web of Science based bibliometric study reveals that there are few papers available in scientific domain. Further, till today not a single paper demonstrated the detailed landfills heterogenicity, chemistry and microbiological processes and their associated dynamics in a combined approach. Accordingly, the paper addresses the recent applications of cutting-edge biogeochemical and biological methods adopted by different countries to sketch an emerging perspective of landfill biological and biogeochemical reactions and dynamics. Additionally, the significance of several regulatory factors controlling the landfill's biogeochemical and biological processes is highlighted. Finally, this article emphasizes the future opportunities for integrating advanced techniques to explain landfill chemistry explicitly. In conclusion, this paper will provide a comprehensive vision of the diverse dimensions of landfill biological and biogeochemical reactions and dynamics to the scientific world and policymakers.
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Affiliation(s)
- Tridib Mondal
- Department of Chemistry, Sukanta Mahavidyalaya, University of North Bengal, Dhupguri 735210, West Bengal, India
| | - Moharana Choudhury
- Environmental Research and Management Division, Voice of Environment (VoE), Guwahati - 781034, Assam, India.
| | - Debajyoti Kundu
- Waste Re-processing Division, CSIR-National Environmental Engineering Research Institute, Nehru Marg, Nagpur 440 020, India
| | - Deblina Dutta
- Department of Environmental Science and Engineering, SRM University-AP, Amaravati, Andhra Pradesh 522 240, India
| | - Palas Samanta
- Department of Environmental Science, Sukanta Mahavidyalaya, University of North Bengal, Dhupguri 735210, West Bengal, India.
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Manheim DC, Newman S, Yeşiller N, Hanson JL, Guha A. Application of cavity ring-down spectroscopy and a novel near surface Gaussian plume estimation approach to inverse model landfill methane emissions. MethodsX 2023; 10:102048. [PMID: 36824994 PMCID: PMC9941205 DOI: 10.1016/j.mex.2023.102048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 01/30/2023] [Indexed: 02/04/2023] Open
Abstract
Fugitive methane emissions from municipal solid waste landfills impact global climate change and reliable emissions quantification is of increasing importance. Ground-based cavity ring-down spectrometer (CRDS) measurements were used to determine methane concentrations and isotopic compositions of carbon in CH4. Then, CH4 oxidation through various cover materials was assessed using the Keeling plot method. A novel inverse modeling approach using Gaussian dispersion analysis, termed near-surface Gaussian plume estimation (NSGPE), was developed to predict whole-site landfill methane emissions. The concentration data obtained around the landfill perimeter with the mobile ground-based CRDS were used. Methane concentration data were integrated to parameterize discretized point source emissions from a Gaussian dispersion model. Post-processing algorithms were applied to refine modeling predictions to account for the influence of topographical and meteorological conditions on methane transport. Results indicate spatially resolved and consistent emissions estimates among multiple optimization simulations, with refinements increasing the resolution and spatial trends of emissions. Post-processing algorithms resolve consistent overestimation of emissions commonly observed using conventional Gaussian dispersion models.•Ground-based CRDS used to obtain methane concentration and oxidation data.•Novel inverse Gaussian dispersion modeling approach developed to predict methane emissions from landfills accounting for site-specific topography and meteorology.•Post-processing algorithms refine emissions estimates.
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Affiliation(s)
- Derek C. Manheim
- Global Waste Research Institute, California Polytechnic State University, 1 Grand Ave, San Luis Obispo, CA 93407, United States of America,Corresponding author.
| | - Sally Newman
- Bay Area Air Quality Management District, 375 Beale St, Suite 600, San Francisco, California 94105, United States of America
| | - Nazli Yeşiller
- Global Waste Research Institute, California Polytechnic State University, 1 Grand Ave, San Luis Obispo, CA 93407, United States of America
| | - James L. Hanson
- Civil and Environmental Engineering Department, California Polytechnic State University, 1 Grand Ave, San Luis Obispo, California 93407, United States of America
| | - Abhinav Guha
- Bay Area Air Quality Management District, 375 Beale St, Suite 600, San Francisco, California 94105, United States of America
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Yeşiller N, Hanson JL, Manheim DC, Newman S, Guha A. Assessment of methane emissions from a California landfill using concurrent experimental, inventory, and modeling approaches. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 154:146-159. [PMID: 36242816 DOI: 10.1016/j.wasman.2022.09.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 09/12/2022] [Accepted: 09/23/2022] [Indexed: 06/16/2023]
Abstract
Methane flux and emissions were obtained at a California landfill concurrently using field measurements, inventory analyses, and modeling. Measured fluxes ranged from -3.7 to 828 g/m2-day and generally decreased from daily to intermediate to final covers. Soil covers with high-plasticity clay had the lowest fluxes. Whole-site emissions ranged from 406 to 47,414 tonnes/year (11,368 to 1,327,592 tonnes CO2-eq./year), and were dominated by intermediate covers with high relative surface area. Emissions estimates from flux chamber tests and California Landfill Methane Inventory Model (CALMIM) with oxidation were similar and low, whereas emissions from aerial measurements and CALMIM without oxidation were similar and high. The inventory analyses provided intermediate emissions and a new Gaussian plume model based on ground cavity ring-down spectrometer measurements provided the highest emissions. The assumptions used and the inherent strengths and limitations of the different approaches resulted in the flux and emissions differences. With varied attributes (experimental/modeling; flux/emissions; whole-site/cover-specific, top-down/bottom-up), the approaches provide envelopes of methane emissions and can be used selectively for the two main purposes of landfill methane emissions analysis: to mechanistically determine the factors that control/limit surface emissions and to provide data for atmospheric methane analysis. To reduce emissions, progression from temporary to permanent cover areas can be accelerated and covers with coarser materials can be amended with plastic fines.
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Affiliation(s)
- Nazli Yeşiller
- Global Waste Research Institute, California Polytechnic State University, 1 Grand Ave, San Luis Obispo, CA 93407, USA.
| | - James L Hanson
- Civil and Environmental Engineering Department, California Polytechnic State University, 1 Grand Ave, San Luis Obispo CA, 93407, USA.
| | - Derek C Manheim
- Global Waste Research Institute, California Polytechnic State University, 1 Grand Ave, San Luis Obispo, CA 93407, USA.
| | - Sally Newman
- Bay Area Air Quality Management District, 375 Beale St, Suite 600, San Francisco, CA 94105, USA.
| | - Abhinav Guha
- Bay Area Air Quality Management District, 375 Beale St, Suite 600, San Francisco, CA 94105, USA.
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9
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Landfill Emissions of Methane Inferred from Unmanned Aerial Vehicle and Mobile Ground Measurements. ATMOSPHERE 2022. [DOI: 10.3390/atmos13060983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Municipal solid waste landfills are significant sources of atmospheric methane, the second most important greenhouse gas after carbon dioxide. Large emissions of methane from landfills contribute not only to global climate change, but also to local ozone formation due to the enhancement of radical chain lengths in atmospheric reactions of volatile organic compounds and nitrogen oxides. Several advanced techniques were deployed to measure methane emissions from two landfills in the Southeast Michigan ozone nonattainment area during the Michigan–Ontario Ozone Source Experiment (MOOSE). These techniques included mobile infrared cavity ringdown spectrometry, drone-mounted meteorological sensors and tunable diode laser spectrometry, estimation of total landfill emissions of methane based on flux plane measurements, and Gaussian plume inverse modeling of distributed methane emissions in the presence of complex landfill terrain. The total methane emissions measured at the two landfills were of the order of 500 kg/h, with an uncertainty of around 50%. The results indicate that both landfill active faces and leaking gas collection systems are important sources of methane emissions.
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Fathinezhad A, Jafari NH, Oldenburg CM, Caldwell MD. Numerical investigation of air intrusion and aerobic reactions in municipal solid waste landfills. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 147:60-72. [PMID: 35623262 DOI: 10.1016/j.wasman.2022.05.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/18/2022] [Accepted: 05/10/2022] [Indexed: 06/15/2023]
Abstract
Air intrusion into municipal solid waste landfills can cause a localized switch from anaerobic to aerobic biodegradation adjacent to the intrusion. The purpose of this study was to explore the effects on temperature and gas composition of air intrusion into an idealized anaerobic landfill. Two scenarios of air intrusion and injection were simulated using a mechanistic landfill model built into TOUGH2. The modeled landfill geometry and properties are based on an actual U.S. landfill. The simulation results show that air intrusion can cause a quick switch from anaerobic to aerobic conditions and as a result, cause a fast increase in temperature of up to 30 °C associated with stimulation of aerobic biodegradation reactions. Associated with the change to aerobic conditions is a decrease in CH4/CO2 (v/v) ratio in the landfill gas. Depending on the air flow rate intruding or injecting into the landfill, localized aerobic biodegradation is stimulated and as a result heat generation rate of 10 to 150 W/m3 leads to temperature increase. Temperature increase near a temporary air intrusion lasts no longer than a few weeks while the high temperatures in deep layers could last up to one year.
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Affiliation(s)
- Alborz Fathinezhad
- Dept. of Civil and Environmental Engineering, Louisiana State University, Baton Rouge, LA 70803, United States.
| | - Navid H Jafari
- Dept. of Civil and Environmental Engineering, Louisiana State University, Baton Rouge, LA 70803, United States.
| | - Curtis M Oldenburg
- Energy Geosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States.
| | - Michael D Caldwell
- Groundwater and Technical Program, Waste Management, Inc., Houston, TX, United States.
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11
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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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12
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Wangyao K, Sutthasil N, Chiemchaisri C. Methane and nitrous oxide emissions from shallow windrow piles for biostabilisation of municipal solid waste. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2021; 71:650-660. [PMID: 33481686 DOI: 10.1080/10962247.2021.1880498] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/17/2020] [Accepted: 01/11/2021] [Indexed: 06/12/2023]
Abstract
Shallow windrow piles were applied as a low-cost option for biostabilisation of municipal solid wastes (MSW) prior to their utilization as refuse-derived fuel (RDF). A considerable amount of greenhouse gas (GHG) emissions can be emitted during the biostabilisation of MSW, especially when in operation under high moisture conditions such as there are in tropical Asia. This study investigated the emission of methane (CH4) and nitrous oxide (N2O) from shallow windrow piles - with heights of 0.5-1.0 m - for the stabilization of MSW at a full-scale facility in Thailand. Measurements of CH4, CO2, and N2O emissions using the static-chamber method revealed high spatial heterogeneity characteristics in all zones with different waste ages. Peak methane emissions were observed after four months of biostabilisation. The average spatial methane emissions from the waste piles ranged from 7.33 to 26.88 g m-2 d-1 (14.86 g m-2 d-1, on average). The CH4 generation-rate constant was within the range of 3.3 to 4.0 yr-1, which is higher than that reported - about 2.20-3.50 yr-1 - from a deep windrow pile (3.5-4.0 m height). The spatial distribution of N2O emissions was in the range of 4.51-199.14 mg N2O t-1dry wt.d-1 (6.6-111.7 mg N2O m-2 d-1), similar to those previously studied from landfill operations. This shallow windrow pile technique can be applied as low-cost technology for biostabilisation of MSW in developing countries, where land area is available.Implications: Shallow windrow pile was applied as a low-cost option for biological treatment of municipal solid waste in developing countries where land area is available. This study evaluated the greenhouse gas emission characteristics during the operation of windrow pile. The findings suggest that the emission rates were varied spatially with waste ages in different zones. Higher methane generation rate constant was derived from shallow window pile as compared to deep windrow pile. The methane and nitrous oxide emission factors were derived.
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Affiliation(s)
- Komsilp Wangyao
- The Joint Graduate School of Energy and Environment, King Mongkut's University of Technology Thonburi, Bangkok, Thailand
- Center of Excellence on Energy Technology and Environment (CEE), PERDO, Ministry of Higher Education, Science, Research and Innovation, Bangkok, Thailand
| | - Noppharit Sutthasil
- Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies, Ibaraki, Japan
| | - Chart Chiemchaisri
- Department of Environmental Engineering, Faculty of Engineering, Kasetsart University, Bangkok, Thailand
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13
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Zhang C, Wang X, Wei L, Wang B, Chen S. Time-resolved characteristics and production pathways of simulated landfilling N 2O emission under different oxygen concentrations. ENVIRONMENT INTERNATIONAL 2021; 149:106396. [PMID: 33524669 DOI: 10.1016/j.envint.2021.106396] [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: 09/26/2020] [Revised: 11/24/2020] [Accepted: 01/09/2021] [Indexed: 06/12/2023]
Abstract
Nitrous oxide (N2O), an important greenhouse gas, is emitted from landfill reservoirs, especially in the working face, where nitrification and denitrification occur under different O2 concentrations. In order to explore the effects of O2 concentration on N2O emissions and production pathways, the production of N2O from simulated fresh waste landfilling under 0%, 5%, 10%, and 21% (vol/vol) O2 concentrations were examined, and 15N isotopes were used as tracers to determine the contributions of nitrification (NF), heterotrophic denitrification (HD), and nitrification-coupled denitrification (NCD) to N2O production over a 72-h incubation period. Equal amounts of total nitrogen consumption occurred for all studied O2 concentration and the simulated waste tended to release more N2O under 0% and 21% O2. Heterotrophic denitrification was the main source of N2O release at the studied oxygen concentrations, contributing 90.51%, 69.04%, 80.75%, and 57.51% of N2O under O2 concentrations of 0%, 5%, 10%, and 21%, respectively. Only denitrification was observed in the simulated fresh waste when the oxygen concentration of the bulk atmosphere was 0%. The nitrate reductase (nirS)-encoding denitrifiers in the simulated landfill were also studied and significant differences were observed in the richness and diversity of the denitrifying community at different taxonomic levels. It was determined that optimising the O2 content is a crucial factor in N2O production that may allow greenhouse gas emissions and N turnover during landfill aeration to be minimised.
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Affiliation(s)
- Chengliang Zhang
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China; Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Xiaojun Wang
- Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Lai Wei
- Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Boguang Wang
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China
| | - Shaohua Chen
- Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
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14
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Yilmaz M, Tinjum JM, Acker C, Marten B. Transport mechanisms and emission of landfill gas through various cover soil configurations in an MSW landfill using a static flux chamber technique. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 280:111677. [PMID: 33243624 DOI: 10.1016/j.jenvman.2020.111677] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 11/09/2020] [Accepted: 11/10/2020] [Indexed: 06/11/2023]
Abstract
This study evaluated the transport mechanisms and emission rates of landfill gas (LFG) from 200- (vegetated with short grass), 300- (vegetated with short grass), and 450-mm-thick (non-vegetated) interim cover soils within a municipal solid waste landfill. LFG emission and diffusion mechanisms were evaluated using static flux chambers and laboratory-scale diffusion columns. Overall, the greatest CH4 and CO2 emissions were consistently observed from the 200-mm-thick cover soil with an average flux rate of 39.2 mg m-2 h-1 and 3.07 × 103 mg m-2 h-1, respectively. In addition to CH4 and CO2, H2S migration through a 450-mm interim cover soil was also evaluated. The H2S emission rate was relatively more uniform at an average of 2.47 × 10-5 mg m-2 h-1. Long-term LFG emission was predicted using an emission model based on a first-order decomposition rate equation and compared with the static flux chamber method. The field-measured CO2, CH4 and H2S emissions were less than the estimated emissions from the emission model, by 22%, 85%, and 91%, respectively. Further, the diffusion coefficients of CH4, CO2, and H2S for the interim cover soils were determined using a laboratory-scale diffusion column test and compared with a three-parameter diffusion model. The measured and estimated diffusion coefficients for the three landfill gases were within the 10% variation limits. Based on these findings, the LFG emission rate varied depending on the physical-chemical properties of the cover soil (e.g., cover thickness, moisture content, compaction ratio, uneven distribution of soil), organic material content and age of buried refuse, and seasonal environmental conditions (such as temperature). Test results showed that fugitive CH4 emissions can be reduced one fourth by utilizing an appropriate cover soil (300-mm to 450-mm, CL) compared to cases with a thinner cover soil.
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Affiliation(s)
- Mehmet Yilmaz
- Civil Engineering, Bitlis Eren University, Bitlis, Turkey.
| | - James M Tinjum
- Civil and Environmental Engineering and Geological Engineering, University of Wisconsin-Madison, Madison, WI, USA.
| | - Connor Acker
- Staff Engineering, Westwood Professional Services, WI, USA.
| | - Brooke Marten
- Environmental Engineering, University of Colorado at Boulder, Boulder, CO, USA.
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15
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Gonzalez-Valencia R, Magana-Rodriguez F, Martinez-Cruz K, Fochesatto GJ, Thalasso F. Spatial and temporal distribution of methane emissions from a covered landfill equipped with a gas recollection system. WASTE MANAGEMENT (NEW YORK, N.Y.) 2021; 121:373-382. [PMID: 33422924 DOI: 10.1016/j.wasman.2020.12.017] [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: 05/13/2020] [Revised: 12/12/2020] [Accepted: 12/13/2020] [Indexed: 06/12/2023]
Abstract
A previously developed surface probe method, which allows for instantaneous methane (CH4) flux measurement, was used to establish CH4 emission maps of a municipal landfill with a final clay cover and equipped with a gas recollection system. In addition to spatial variations, the method was applied at 7 different times over a total timeframe of 65 h and under similar weather conditions to determine the intrinsic temporal variations of CH4 emissions; i.e., the temporal variation related to the dynamic of the landfill rather than the one driven by external factors. Furthermore, continuous CH4 fluxes, with a data acquisition frequency of 1 Hz, were measured during 12 h at a single position, and for one hour at 22 locations of the landfill, spanning a large range of CH4 emission magnitudes. A simple model for the numerical characterization of spatiotemporal variability of the landfill emission was used and allowed us to separately quantify the temporal and spatial variability. This model showed that, in the landfill tested, the temporal distribution of CH4 emissions resulted more homogeneous than the spatial distribution. Other attributes of the temporal and spatial distributions of CH4 emissions were also established including the anisotropic nature of the spatial distribution and, contrastingly, the stochastic temporal variability of such emissions.
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Affiliation(s)
- Rodrigo Gonzalez-Valencia
- Departamento de Biotecnología y Bioingeniería, Cinvestav, Mexico City D.F., Av. IPN 2508, 07360 México DF, Mexico
| | - Felipe Magana-Rodriguez
- Departamento de Biotecnología y Bioingeniería, Cinvestav, Mexico City D.F., Av. IPN 2508, 07360 México DF, Mexico
| | - Karla Martinez-Cruz
- Departamento de Biotecnología y Bioingeniería, Cinvestav, Mexico City D.F., Av. IPN 2508, 07360 México DF, Mexico
| | - Gilberto J Fochesatto
- Department of Atmospheric Sciences, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| | - Frederic Thalasso
- Departamento de Biotecnología y Bioingeniería, Cinvestav, Mexico City D.F., Av. IPN 2508, 07360 México DF, Mexico.
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16
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Li H, Meng B, Yue B, Gao Q, Ma Z, Zhang W, Li T, Yu L. Seasonal CH 4 and CO 2 effluxes in a final covered landfill site in Beijing, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 725:138355. [PMID: 32464750 DOI: 10.1016/j.scitotenv.2020.138355] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 03/24/2020] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
As the main solid waste disposal method in China, landfill sites are considerable sources of methane (CH4) and carbon dioxide (CO2). This study characterized the seasonal variation of CH4 and CO2 effluxes at a large and well-managed final covered landfill site in China. A three-year monitoring program was conducted. There were two different seasonal variation patterns for hotspot and non-hotspot' CH4 and CO2 effluxes. For non-hotspots, the CH4 and CO2 effluxes' seasonal variations were mainly affected by the seasonal change of the landfill's cover soil respiration activity, particularly the CH4 oxidation capability. CH4 had a higher efflux in winter; in other seasons, the CH4 efflux fluctuated around 0; the CO2 effluxes were (1) increased in spring and peaked in summer or early autumn; (2) then, they decreased to a minimum value in late autumn or early winter; and (3) fluctuated with the CH4 efflux in winter. The CH4 emissions in winter account for 60.4-84.4% of the all year outputs. For the hotspots', the CH4 and CO2 effluxes seasonal variations were mainly determined by the seasonal change of the landfill cover's soil gas permeability. The ratio of CH4 emissions in winter to the all year outputs range from 17.4 to 68.7%.
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Affiliation(s)
- Hailing Li
- LAPC, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Bangbang Meng
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Bo Yue
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Qingxian Gao
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Zhanyun Ma
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Wen Zhang
- LAPC, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Tingting Li
- LAPC, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Lijun Yu
- LAPC, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
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17
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Meyer-Dombard DR, Bogner JE, Malas J. A Review of Landfill Microbiology and Ecology: A Call for Modernization With 'Next Generation' Technology. Front Microbiol 2020; 11:1127. [PMID: 32582086 PMCID: PMC7283466 DOI: 10.3389/fmicb.2020.01127] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 05/05/2020] [Indexed: 12/24/2022] Open
Abstract
Engineered and monitored sanitary landfills have been widespread in the United States since the passage of the Clean Water Act (1972) with additional controls under RCRA Subtitle D (1991) and the Clean Air Act Amendments (1996). Concurrently, many common perceptions regarding landfill biogeochemical and microbiological processes and estimated rates of gas production also date from 2 to 4 decades ago. Herein, we summarize the recent application of modern microbiological tools as well as recent metadata analysis using California, USEPA and international data to outline an evolving view of landfill biogeochemical/microbiological processes and rates. We focus on United States landfills because these are uniformly subject to stringent national and state requirements for design, operations, monitoring, and reporting. From a microbiological perspective, because anoxic conditions and methanogenesis are rapidly established after daily burial of waste and application of cover soil, the >1000 United States landfills with thicknesses up to >100 m form a large ubiquitous group of dispersed 'dark' ecosystems dominated by anaerobic microbial decomposition pathways for food, garden waste, and paper substrates. We review past findings of landfill ecosystem processes, and reflect on the potential impact that application of modern sequencing technologies (e.g., high throughput platforms) could have on this area of research. Moreover, due to the ever evolving composition of landfilled waste reflecting transient societal practices, we also consider unusual microbial processes known or suspected to occur in landfill settings, and posit areas of research that will be needed in coming decades. With growing concerns about greenhouse gas emissions and controls, the increase of chemicals of emerging concern in the waste stream, and the potential resource that waste streams represent, application of modernized molecular and microbiological methods to landfill ecosystem research is of paramount importance.
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Affiliation(s)
- D’Arcy R. Meyer-Dombard
- Department of Earth and Environmental Sciences, University of Illinois at Chicago, Chicago, IL, United States
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18
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Fjelsted L, Scheutz C, Christensen AG, Larsen JE, Kjeldsen P. Biofiltration of diluted landfill gas in an active loaded open-bed compost filter. WASTE MANAGEMENT (NEW YORK, N.Y.) 2020; 103:1-11. [PMID: 31862629 DOI: 10.1016/j.wasman.2019.12.005] [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: 01/28/2019] [Revised: 11/27/2019] [Accepted: 12/03/2019] [Indexed: 06/10/2023]
Abstract
Microbial oxidation in a biofilter is a treatment solution for diluted landfill gas (LFG), for instance at old landfills, where LFG recovery is no longer feasible, or from remediation systems designed to cut off laterally migrating LFG. In this study, an actively loaded open-bed compost filter, designed for the treatment of diluted LFG, was tested at an old landfill in Denmark. An 18 m3 biofilter was constructed in a 30 m3 container loaded with LFG mixed with air, in order to obtain diluted LFG. The inlet concentration of methane (CH4) fluctuated between 4.4 and 9.2 vol% during the five tested flow campaigns, resulting in CH4 loads of 106-794 g CH4 m-2 d-1. The maximum identified CH4 oxidation rate was 460 g m-2 d-1, with an overall CH4 oxidation efficiency of 58%. Due to preferential flows, especially along the edges of the filter at the transition points between the compost and the container wall, an overall CH4 oxidation efficiency of 100% was never achieved. However, pore gas profiles in selected areas in the filter material showed oxidation efficiencies close to 100%. The results were supported by tracer gas tests showing average oxidation efficiency in the nine measuring points of 89% at a CH4 load of 487 ± 64 g CH4 m-2 d-1.
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Affiliation(s)
- L Fjelsted
- NIRAS A/S, Sortemosevej 19, DK-3450 Allerød, Denmark; Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
| | - C Scheutz
- Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | | | - J E Larsen
- NIRAS A/S, Sortemosevej 19, DK-3450 Allerød, Denmark
| | - P Kjeldsen
- Department of Environmental Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
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19
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Zhang C, Guo Y, Wang X, Chen S. Temporal and spatial variation of greenhouse gas emissions from a limited-controlled landfill site. ENVIRONMENT INTERNATIONAL 2019; 127:387-394. [PMID: 30954725 DOI: 10.1016/j.envint.2019.03.052] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 03/22/2019] [Accepted: 03/22/2019] [Indexed: 06/09/2023]
Abstract
Landfilling biodegradable waste is an important source of global greenhouse gas (GHG) emissions. Among the several types of landfill, limited-controlled landfill is a common method used to dispose of domestic solid waste, especially in developing countries. However, information about GHG emissions from limited-controlled landfill sites has rarely been reported. In this study, the GHG emissions from a typical limited-controlled landfill site were investigated under a regular period for one year. The number and positions of static chambers were arranged according to the guidance on Monitoring Landfill Gas Surface Emissions by the UK Environment Agency to obtain representative data from the heterogeneous surface of the landfill. Inverse distance weighting (IDW) was applied to evaluate and visualise the GHG emissions from the whole landfill surface based on the measurements of distributed static chambers. As an important GHG source of the landfill site, the emissions from the landfill leachate treatment plant were also measured. The results revealed that CH4 and N2O emission fluxes from the landfill area were 1324.73 ± 2005.17 mg C m-2 d-1 and 2.16 ± 2.33 mg N m-2 d-1, respectively, and the fluxes from the leachate treatment plants were 23.92 ± 29.20 mg C m-2 d-1 and 16.40 ± 16.89 mg N m-2 d-1, respectively. CH4 and N2O releases preferred to present spatial heterogeneity, while temporal heterogeneity was expected to exist in CH4 and CO2 emissions. The annual GHG emissions from the limited-controlled landfill was calculated to be 1.078 Gg CO2-eq yr-1, which was the least among all types of landfill sites. In addition, the GHG emission factor was 0.042 t CO2-eq t-1 waste yr-1 which could not be ignored compared to the sanitary landfills. Therefore, it is advisable to give more attention and determine a potential solution for reducing GHG emissions from limited-controlled landfill sites.
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Affiliation(s)
- Chengliang Zhang
- Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan Guo
- Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaojun Wang
- Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Shaohua Chen
- Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
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20
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Greenhouse Gas Emissions from Landfills: A Review and Bibliometric Analysis. SUSTAINABILITY 2019. [DOI: 10.3390/su11082282] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The landfill is an important method of disposal of municipal solid waste. In particular, the landfill is especially vital in many developing countries, with it being the main biodegradable waste disposal method due to its simple management and ability for mass manipulation. Landfills have recently been shown to be an important source of greenhouse gas (GHG) emissions by researchers in different countries. However, few reviews have been conducted within the related fields, which means that there is still a lack of comprehensive understanding related to relevant study achievements. In this study, a bibliometric analysis of articles published from 1999 to 2018 on landfill GHG emissions was presented to assess the current trends, using the Web of Science (WOS) database. The most productive countries/territories, authors and journals were analyzed. Moreover, the overall research structure was characterized based on co-cited references, emerging keywords and reference citations by means of bibliometric analysis. Due to the increasing amount of attention being paid to the GHG emissions and their mitigation methods, this study provided comprehensive bibliometric information on GHG emissions from landfills over the past two decades and highlighted the importance of the development and dissemination of updated knowledge frameworks.
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21
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Mønster J, Kjeldsen P, Scheutz C. Methodologies for measuring fugitive methane emissions from landfills - A review. WASTE MANAGEMENT (NEW YORK, N.Y.) 2019; 87:835-859. [PMID: 30660403 DOI: 10.1016/j.wasman.2018.12.047] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 12/22/2018] [Accepted: 12/31/2018] [Indexed: 06/09/2023]
Abstract
Fugitive methane (CH4) emissions from landfills are significant global sources of greenhouse gases emitted into the atmosphere; thus, reducing them would be a beneficial way of overall greenhouse gas emissions mitigation. In Europe, landfill owners have to report their annual CH4 emissions, so direct measurements are therefore important for (1) evaluating and improving currently applied CH4 emission models, (2) reporting annual CH4 emissions and (3) quantifying CH4 mitigation initiatives. This paper aims at providing an overview of currently available methodologies used to measure fugitive CH4 emissions escaping from landfills. The measurement methodologies are described briefly, and the advantages and limitations of the different techniques are discussed with reference to published literature on the subject. Examples are given of individual published studies using different methodologies and studies comparing three or more methodologies. This review suggests that accurate, whole-site CH4 emission quantifications are best done using methods measuring downwind of the landfill, such as tracer gas dispersion and differential absorption LiDAR (DIAL). Combining aerial CH4 concentration measurements from aircraft or unmanned aerial vehicles with wind field measurements offers a great future potential for improved and cost-efficient integrated landfill CH4 emission quantification. However, these methods are difficult to apply for longer time periods, so in order to measure temporal CH4 emission changes, e.g. due to the effect of changes in atmospheric conditions (pressure, wind and precipitation), a measurement method that is able to measure continuously is required. Such a method could be eddy covariance or static mass balance, although these procedures are challenged by topography and inhomogeneous spatial emission patterns, and as such they can underestimate emissions significantly. Surface flux chambers have been used widely, but they are likely to underestimate emission rates, due to the heterogeneous nature of most landfill covers resulting in sporadic and localised CH4 emission hotspots being the dominant emission routes. Furthermore, emissions from wells, vents, etc. are not captured by surface flux chambers. The significance of any underestimation depends highly on the configuration of individual landfills, their size and emission patterns.
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Affiliation(s)
- Jacob Mønster
- Department of Environmental Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Peter Kjeldsen
- Department of Environmental Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Charlotte Scheutz
- Department of Environmental Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
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22
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Rees-White TC, Mønster J, Beaven RP, Scheutz C. Measuring methane emissions from a UK landfill using the tracer dispersion method and the influence of operational and environmental factors. WASTE MANAGEMENT (NEW YORK, N.Y.) 2019; 87:870-882. [PMID: 29605306 DOI: 10.1016/j.wasman.2018.03.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 01/30/2018] [Accepted: 03/11/2018] [Indexed: 06/08/2023]
Abstract
The methane emissions from a landfill in south-east, UK were successfully quantified during a six-day measurement campaign using the tracer dispersion method. The fair weather conditions made it necessary to perform measurements in the late afternoon and in the evening when the lower solar flux resulted in a more stable troposphere with a lower inversion layer. This caused a slower mixing of the gasses, but allowed plume measurements up to 6700 m downwind from the landfill. The average methane emission varied between 217 ± 14 and 410 ± 18 kg h-1 within the individual measurement days, but the measured emission rates were higher on the first three days (333 ± 27, 371 ± 42 and 410 ± 18 kg h-1) compared to the last three days (217 ± 14, 249 ± 20 and 263 ± 22 kg h-1). It was not possible to completely isolate the extent to which these variations were a consequence of measuring artefacts, such as wind/measurement direction and measurement distance, or from an actual change in the fugitive emission. Such emission change is known to occur with changes in the atmospheric pressure. The higher emissions measured during the first three days of the campaign were measured during a period with an overall decrease in atmospheric pressure (from approximately 1014 mbar on day 1 to 987 mbar on day 6). The lower emissions measured during the last three days of the campaign were carried out during a period with an initial pressure increase followed by a period of slowly reducing pressure. The average daily methane recovery flow varied between 633 and 679 kg h-1 at STP (1 atm, 0 °C). The methane emitted to the atmosphere accounted for approximately 31% of the total methane generated, assuming that the methane generated is the sum of the methane recovered and the methane emitted to the atmosphere, thus not including a potential methane oxidation in the landfill cover soil.
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Affiliation(s)
- T C Rees-White
- Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, UK
| | - J Mønster
- Department of Environmental Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - R P Beaven
- Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ, UK
| | - C Scheutz
- Department of Environmental Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
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23
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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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24
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Yun J, Jung H, Choi H, Oh KC, Jeon JM, Ryu HW, Cho KS. Performance evaluation of an on-site biocomplex textile as an alternative daily cover in a sanitary landfill, South Korea. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2018; 36:1137-1145. [PMID: 30376763 DOI: 10.1177/0734242x18806996] [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: 06/08/2023]
Abstract
The performance of a biocomplex textile prototype was evaluated as an alternative daily cover at an operational landfill site to mitigate odors and methane. The biocomplex textile prototype consisted of two layers of nonwoven fabric and biocarrier immobilized microorganisms and showed excellent removal of odors and methane compared to landfill cover soil. The complex odor intensity (odor dilution ratio (ODR)) on the surface of landfill cover soil was 1,000-10,000 ODR (average of 4,204 ODR), whereas it was 5-250 ODR (average of 55 ODR) on the surface of biocomplex textile. Hydrogen sulfide, which contributes a significant odor intensity, had an average concentration on the biocomplex textile of 8.64 parts-per-billion (ppb), compared to 1733.21 ppb on the landfill cover soil. The biocomplex textile also showed effective methane removal with methane concentrations of 0-1.2% (average of 0.3%) on the biocomplex textile compared to 0-20% (average of 5.3%) on the landfill cover soil. Bacterial community diversity in the biocomplex textile increased with time until an operating period of 66 days, after which diversity indices were maintained at a constant level. The dominant species were the methanotrophs Methylocaldum and Methylobacter, and the non-methanotrophs Acinetobacter, Serpens, Ohtaekwangia, and Actinophytocola. These results demonstrate that on-site biocomplex textile is a suitable alternative daily cover to mitigate odors and methane in landfills.
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Affiliation(s)
- Jeonghee Yun
- 1 Department of Environmental Science and Engineering, Ewha Womans University, Seodaemun-gu, Seoul, Republic of Korea
| | - Hyekyeng Jung
- 1 Department of Environmental Science and Engineering, Ewha Womans University, Seodaemun-gu, Seoul, Republic of Korea
| | - Hyungjoo Choi
- 1 Department of Environmental Science and Engineering, Ewha Womans University, Seodaemun-gu, Seoul, Republic of Korea
| | - Kyung-Cheol Oh
- 2 Green Environment Complex Center, Suncheon, Republic of Korea
| | - Jun-Min Jeon
- 2 Green Environment Complex Center, Suncheon, Republic of Korea
| | - Hee Wook Ryu
- 3 Department of Chemical Engineering, Soongsil University, Dongjak-gu, Seoul, Republic of Korea
| | - Kyung-Suk Cho
- 1 Department of Environmental Science and Engineering, Ewha Womans University, Seodaemun-gu, Seoul, Republic of Korea
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Shen S, Chen Y, Zhan L, Xie H, Bouazza A, He F, Zuo X. Methane hotspot localization and visualization at a large-scale Xi'an landfill in China: Effective tool for landfill gas management. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2018; 225:232-241. [PMID: 30092550 DOI: 10.1016/j.jenvman.2018.08.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 08/01/2018] [Accepted: 08/03/2018] [Indexed: 06/08/2023]
Abstract
The variation characteristics and influence factors of methane emission at Jiangchungou landfill, one of the largest landfill in China, has been investigated by a one-year field monitoring campaign during 2015-2016. The methane concentration above the landfill surface varied widely from negligible to 33,975 ppm. At least 75% of the methane concentration values of the sampling points are lower than the allowed limit (500 ppm). More than 95% of the high concentration zones (>500 ppm) were located in the temporary cover area (TA). Several environmental factors were found to be related to the variation of the concentration values. A clear correlation was observed between barometric pressure and exceeding-standard areas with a correlation coefficient of -0.743 (p < 0.1). The concentration values in the final cover area (FA) were about one order of magnitude lower than those observed in the TA due to the fact that rapid methane production rate happened in the first 180 days after the high kitchen content wastes were landfilled. The percentages of the measured concentration values exceeding 500 ppm near the gas collection wells in TA zone were 71.5% in November, 2015 and 55.7% in January, 2016 due to the leakage from the sides of gas collection wells. The average methane concentration values on the HDPE geomembrane was higher than those observed on the loess cover due to the fact that the geomembrane was relatively thin (0.5 mm) and can be easily damaged by the operation vehicles. Thicker geomembranes (>1.5 mm) with a good construction quality control are expected to provide better performance at this site.
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Affiliation(s)
- Siliang Shen
- MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Yunmin Chen
- MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Liangtong Zhan
- MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Haijian Xie
- MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China.
| | - Abdelmalek Bouazza
- Department of Civil Engineering, Monash University, Clayton, Melbourne, Vic, 3168, Australia
| | - Feiyu He
- MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Xinru Zuo
- MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
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Krause MJ. Intergovernmental panel on climate change's landfill methane protocol: Reviewing 20 years of application. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2018; 36:827-840. [PMID: 30168388 DOI: 10.1177/0734242x18793935] [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: 06/08/2023]
Abstract
The Intergovernmental Panel on Climate Change (IPCC) protocol for predicting national methane emission inventories from landfills was published 22 years ago in the 1996 Revised Guidelines. There currently exists a broad dataset to review landfill parameters and reported values and their appropriateness in use and application in a range of site-specific, regional, and national estimates. Degradable organic carbon (DOC) content was found to range from 0.0105 to 0.65 g C/g waste, with an average of 0.166 g C/g waste. The fraction of DOC that would anaerobically degrade (DOC f) was reported to range from 50-83%, whereas higher and lower values have been experimentally determined for a variety of waste components, such as wood (0-50%) and food waste (50-75%). Where field validation occurred for the methane correction factor, values were substantially lower than defaults. The fraction of methane in anaerobic landfill gas ( F) default of 50% is almost universally applied and is appropriate for cellulosic wastes. The methane generation rate constant ( k) varied widely from 0.01 to 0.51 y-1, representing half-lives from 1 to 69 years. Methane oxidation (OX) default values of 0 and 10% may be valid, but values greater than 30% have been reported for porous covers at managed sites. The IPCC protocol is a practical tool with uncertainties and limitations that must be addressed when used for purposes other than developing inventories.
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Affiliation(s)
- Max J Krause
- Oak Ridge Institute for Science and Education, Cincinnati, USA
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Obersky L, Rafiee R, Cabral AR, Golding SD, Clarke WP. Methodology to determine the extent of anaerobic digestion, composting and CH 4 oxidation in a landfill environment. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 76:364-373. [PMID: 29798807 DOI: 10.1016/j.wasman.2018.02.029] [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: 07/26/2017] [Revised: 02/10/2018] [Accepted: 02/13/2018] [Indexed: 06/08/2023]
Abstract
An examination of the processes contributing to the production of landfill greenhouse gas (GHG) emissions is required, as the actual level to which waste degrades anaerobically and aerobically beneath covers has not been differentiated. This paper presents a methodology to distinguish between the rate of anaerobic digestion (rAD), composting (rCOM) and CH4 oxidation (rOX) in a landfill environment, by means of a system of mass balances developed for molecular species (CH4, CO2) and stable carbon isotopes (δ13C-CO2 and δ13C-CH4). The technique was applied at two sampling locations on a sloped area of landfill. Four sampling rounds were performed over an 18 month period after a 1.0 m layer of fresh waste and 30-50 cm of silty clay loam had been placed over the area. Static chambers were used to measure the flux of the molecular and isotope species at the surface and soil gas probes were used to collect gas samples at depths of approximately 0.5, 1.0 and 1.5 m. Mass balances were based on the surface flux and the concentration of the molecular and isotopic species at the deepest sampling depth. The sensitivity of calculated rates was considered by randomly varying stoichiometric and isotopic parameters by ±5% to generate at least 500 calculations of rOX, rAD and rCOM for each location in each sampling round. The resulting average value of rAD and rCOM indicated anaerobic digestion and composting were equally dominant at both locations. Average values of rCOM: ranged from 9.8 to 44.5 g CO2 m-2 d-1 over the four sampling rounds, declining monotonically at one site and rising then falling at the other. Average values of rAD: ranged from 10.6 to 45.3 g CO2 m-2 d-1. Although the highest average rAD value occurred in the initial sampling round, all subsequent rAD values fell between 10 and 20 g CO2 m-2 d-1. rOX had the smallest activity contribution at both sites, with averages ranging from 1.6 to 8.6 g CO2 m-2 d-1. This study has demonstrated that for an interim cover, composting and anaerobic digestion of shallow landfill waste can occur simultaneously.
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Affiliation(s)
- Lizanne Obersky
- Centre for Solid Waste Bioprocessing, Schools of Civil and Chemical Engineering, The University of Queensland, St. Lucia, Queensland 4072, Australia.
| | - Reza Rafiee
- Centre for Solid Waste Bioprocessing, Schools of Civil and Chemical Engineering, The University of Queensland, St. Lucia, Queensland 4072, Australia; Department of Environmental Sciences, Faculty of Natural Resources, University of Tehran, Karaj, 31536, Iran
| | - Alexandre R Cabral
- Geoenvironmental Group, Dept. of Civil Engineering, University of Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada
| | - Suzanne D Golding
- Earth and Environmental Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - William P Clarke
- Centre for Solid Waste Bioprocessing, Schools of Civil and Chemical Engineering, The University of Queensland, St. Lucia, Queensland 4072, Australia.
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Rafiee R, Obersky L, Xie S, Clarke WP. Pilot scale evaluation of a model to distinguish the rates of simultaneous anaerobic digestion, composting and methane oxidation in static waste beds. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 71:156-163. [PMID: 29126823 DOI: 10.1016/j.wasman.2017.11.003] [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: 07/15/2017] [Revised: 10/30/2017] [Accepted: 11/01/2017] [Indexed: 06/07/2023]
Abstract
The aim of this paper was to apply and validate a model for measuring the rate and extent of anaerobic digestion, composting and CH4 oxidation in laboratory scale beds. Degradation studies were performed in four reactors each packed with shredded unsorted municipal solid waste, with one bed covered with a 100 mm layer of soil. The rates of production of CH4, CO2, 13C-CO2 and the rate of consumption of O2 were measured and used as inputs to a mass balance expressions for these components to calculate the rates of anaerobic digestion, composting and CH4 oxidation. The results showed that anaerobic digestion, composting and CH4 oxidation occurred simultaneously in both the covered and uncovered beds. The analysis showed that 50 ± 4% of the solids (COD basis) in the uncovered beds degraded anaerobically, with the generated CH4 subsequently oxidized, and that 32 ± 4% of the solids degraded aerobically in the covered bed.
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Affiliation(s)
- Reza Rafiee
- Centre for Solid Waste Bioprocessing, Schools of Civil and Chemical Engineering, The University of Queensland, Brisbane 4072, Australia; Department of Environmental Sciences, Faculty of Natural Resources, University of Tehran, Karaj, Iran(1).
| | - Lizanne Obersky
- Centre for Solid Waste Bioprocessing, Schools of Civil and Chemical Engineering, The University of Queensland, Brisbane 4072, Australia
| | - Sihuang Xie
- Centre for Solid Waste Bioprocessing, Schools of Civil and Chemical Engineering, The University of Queensland, Brisbane 4072, Australia
| | - William P Clarke
- Centre for Solid Waste Bioprocessing, Schools of Civil and Chemical Engineering, The University of Queensland, Brisbane 4072, Australia.
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Wang X, Jia M, Zhang H, Pan S, Kao CM, Chen S. Quantifying N 2O emissions and production pathways from fresh waste during the initial stage of disposal to a landfill. WASTE MANAGEMENT (NEW YORK, N.Y.) 2017; 63:3-10. [PMID: 27523711 DOI: 10.1016/j.wasman.2016.08.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 07/21/2016] [Accepted: 08/05/2016] [Indexed: 06/06/2023]
Abstract
Intensive nitrous oxide (N2O) emissions usually occur at the working face of landfills. However, the specific amounts and contributions of the multiple pathways to N2O emissions are poorly understood. N2O emissions and the mutual conversions of N-species in both open and sealed simulated landfill reactors filled with fresh refuse were examined during a 100-h incubation period, and N2O sources were calculated using 15N isotope labelling. N2O peak fluxes were above 70μgNkg-1 waste h-1 for both treatments. The sealed incubation reactors became a N2O sink when N2O in the ambient environment was sufficient. The total amount of N2O emissions under sealed conditions was 2.15±0.56mgNkg-1 waste, which was higher than that under open conditions (1.91±0.34mgNkg-1 waste). The NO2- peak appeared prior to the peak in N2O flux. The degree and duration of total nitrogen reduction in open incubations were larger and longer than those of sealed incubations and could possibly be due to oxygen supplementation. Denitrification (DF) was a major source of N2O generation during these incubations. The contribution of the DF pathway decreased from 89.2% to 61.3% during the open incubations. The effects of nitrification (NF) and nitrification-coupled denitrification (NCD) increased during the increasing phase and the decreasing phase of N2O flux, contributing 24.1-37.4% and 31.7-34.4% of total N2O emissions, respectively. In sealed treatments, the DF pathway accounted for more than 90% of the total N2O emission during the entire incubation.
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Affiliation(s)
- Xiaojun Wang
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
| | - Mingsheng Jia
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
| | - Han Zhang
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
| | - Songqing Pan
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
| | - Chih Ming Kao
- Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan.
| | - Shaohua Chen
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
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30
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Rafiee R, Obersky L, Xie S, Clarke WP. A mass balance model to estimate the rate of composting, methane oxidation and anaerobic digestion in soil covers and shallow waste layers. WASTE MANAGEMENT (NEW YORK, N.Y.) 2017; 63:196-202. [PMID: 28089399 DOI: 10.1016/j.wasman.2016.12.025] [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: 06/01/2016] [Revised: 12/02/2016] [Accepted: 12/17/2016] [Indexed: 06/06/2023]
Abstract
Although CH4 oxidation in landfill soil covers is widely studied, the extent of composting and CH4 oxidation in underlying waste layers has been speculated but not measured. The objective of this study was to develop and validate a mass balance model to estimate the simultaneous rates of anaerobic digestion (rAD), CH4 oxidation (rOX) and composting (rCOM) in environments where O2 penetration is variable and zones of aerobic and anaerobic activity are intermingled. The modelled domain could include, as an example, a soil cover and the underlying shallow waste to a nominated depth. The proposed model was demonstrated on a blend of biogas from three separate known sources of gas representing the three reaction processes: (i) a bottle of laboratory grade 50:50% CH4:CO2 gas representing anaerobic digestion biogas; (ii) an aerated 250mL bottle containing food waste that represented composting activity; and (iii) an aerated 250mL bottle containing non-degradable graphite granules inoculated with methanotrophs and incubated with CH4 and O2 to represent methanotrophic activity. CO2, CH4, O2 and the stable isotope 13C-CO2 were chosen as the components for the mass balance model. The three reaction rates, r (=rAD, rOX, rCOM) were calculated as fitting parameters to the overdetermined set of 4mass balance equations with the net flux of these components from the bottles q (= [Formula: see text] , [Formula: see text] , [Formula: see text] and [Formula: see text] ) as inputs to the model. The coefficient of determination (r2) for observed versus modelled values of r were 1.00, 0.97, 0.98 when the stoichiometry of each reaction was based on gas yields measured in the individual bottles and q was calculated by summing yields from the three bottles. r2 deteriorated to 0.95, 0.96, 0.87 when using an average stoichiometry from 11 incubations of each of the composting and methane oxidation processes. The significant deterioration in the estimation of rCOM showed that this output is highly sensitive to the evaluated stoichiometry coefficients for the reactions. r2 deteriorated further to 0.86, 0.77, 0.74 when using the average stoichiometry and experimental measurement of the composition and volume of the blended biogas to determine q. This was primarily attributed to average errors of 8%, 7%, 11% and 14% in the measurement of [Formula: see text] , [Formula: see text] , [Formula: see text] and [Formula: see text] relative to the measurement of the same quantities from the individual bottles.
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Affiliation(s)
- Reza Rafiee
- Centre for Solid Waste Bioprocessing, Schools of Civil and Chemical Engineering, The University of Queensland, Brisbane 4072, Australia
| | - Lizanne Obersky
- Centre for Solid Waste Bioprocessing, Schools of Civil and Chemical Engineering, The University of Queensland, Brisbane 4072, Australia
| | - Sihuang Xie
- Centre for Solid Waste Bioprocessing, Schools of Civil and Chemical Engineering, The University of Queensland, Brisbane 4072, Australia
| | - William P Clarke
- Centre for Solid Waste Bioprocessing, Schools of Civil and Chemical Engineering, The University of Queensland, Brisbane 4072, Australia.
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31
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Wang X, Jia M, Lin X, Xu Y, Ye X, Kao CM, Chen S. A comparison of CH 4, N 2O and CO 2 emissions from three different cover types in a municipal solid waste landfill. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2017; 67:507-515. [PMID: 27996634 DOI: 10.1080/10962247.2016.1268547] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Accepted: 11/21/2016] [Indexed: 06/06/2023]
Abstract
UNLABELLED High-density polyethylene (HDPE) membranes are commonly used as a cover component in sanitary landfills, although only limited evaluations of its effect on greenhouse gas (GHG) emissions have been completed. In this study, field GHG emission were investigated at the Dongbu landfill, using three different cover systems: HDPE covering; no covering, on the working face; and a novel material-Oreezyme Waste Cover (OWC) material as a trial material. Results showed that the HDPE membrane achieved a high CH4 retention, 99.8% (CH4 mean flux of 12 mg C m-2 h-1) compared with the air-permeable OWC surface (CH4 mean flux of 5933 mg C m-2 h-1) of the same landfill age. Fresh waste at the working face emitted a large fraction of N2O, with average fluxes of 10 mg N m-2 h-2, while N2O emissions were small at both the HDPE and the OWC sections. At the OWC section, CH4 emissions were elevated under high air temperatures but decreased as landfill age increased. N2O emissions from the working face had a significant negative correlation with air temperature, with peak values in winter. A massive presence of CO2 was observed at both the working face and the OWC sections. Most importantly, the annual GHG emissions were 4.9 Gg yr-1 in CO2 equivalents for the landfill site, of which the OWC-covered section contributed the most CH4 (41.9%), while the working face contributed the most N2O (97.2%). HDPE membrane is therefore, a recommended cover material for GHG control. IMPLICATIONS Monitoring of GHG emissions at three different cover types in a municipal solid waste landfill during a 1-year period showed that the working face was a hotspot of N2O, which should draw attention. High CH4 fluxes occurred on the permeable surface covering a 1- to 2-year-old landfill. In contrast, the high-density polyethylene (HDPE) membrane achieved high CH4 retention, and therefore is a recommended cover material for GHG control.
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Affiliation(s)
- Xiaojun Wang
- a CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen , People's Republic of China
| | - Mingsheng Jia
- a CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen , People's Republic of China
| | - Xiangyu Lin
- a CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen , People's Republic of China
| | - Ying Xu
- a CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen , People's Republic of China
| | - Xin Ye
- a CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen , People's Republic of China
| | - Chih Ming Kao
- b Institute of Environmental Engineering , National Sun Yat-Sen University , Kaohsiung , Taiwan, Republic of China
| | - Shaohua Chen
- a CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen , People's Republic of China
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32
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Nagamori M, Mowjood MIM, Watanabe Y, Isobe Y, Ishigaki T, Kawamoto K. Characterization of temporal variations in landfill gas components inside an open solid waste dump site in Sri Lanka. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2016; 66:1257-1267. [PMID: 27575846 DOI: 10.1080/10962247.2016.1212746] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 07/08/2016] [Indexed: 06/06/2023]
Abstract
UNLABELLED A long-term monitoring of composition of landfill gases in the region with high rainfall was conducted using an argon assay in order to discuss air intrusion into the dump site. Gas samples were taken from vertical gas monitoring pipes installed along transects at two sections (called new and old) of an abandoned waste dump site in Sri Lanka. N2O concentrations varied especially widely, by more than three orders of magnitude (0.046-140 ppmv). The nitrogen/argon ratio of landfill gas was normally higher than that of fresh air, implying that denitrification occurred in the dump site. Argon assays indicate that both N2 and N2O production occurred inside waste and more significantly in the old section. The Ar assay would help for evaluations of N2O emission in developing countries. IMPLICATIONS A long-term monitoring of composition of landfill gases in the region with high rainfall was conducted using an argon assay in order to discuss air intrusion into the dump site. Argon assays indicate that both N2 and N2O production occurred inside waste and more significantly in the old section.
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Affiliation(s)
- Masanao Nagamori
- a Center for Environmental Science in Saitama , Kazo , Saitama , Japan
| | - M I M Mowjood
- b Department of Agricultural Engineering, Faculty of Agriculture , University of Peradeniya , Peradeniya , Sri Lanka
| | - Youichi Watanabe
- a Center for Environmental Science in Saitama , Kazo , Saitama , Japan
| | - Yugo Isobe
- a Center for Environmental Science in Saitama , Kazo , Saitama , Japan
| | - Tomonori Ishigaki
- c Center for Material Cycles and Waste Management, National Institute for Environmental Studies , Tsukuba , Ibaraki , Japan
| | - Ken Kawamoto
- d Graduate School of Science and Engineering, Saitama University , Sakura-ku, Saitama , Saitama , Japan
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Long XE, Wang J, Huang Y, Yao H. Microbial community structures and metabolic profiles response differently to physiochemical properties between three landfill cover soils. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:15483-15494. [PMID: 27117156 DOI: 10.1007/s11356-016-6681-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 04/11/2016] [Indexed: 06/05/2023]
Abstract
Landfills are always the most important part of solid waste management and bear diverse metabolic activities involved in element biogeochemical cycling. There is an increasing interest in understanding the microbial community and activities in landfill cover soils. To improve our knowledge of landfill ecosystems, we determined the microbial physiological profiles and communities in three landfill cover soils (Ninghai: NH, Xiangshan: XS, and Fenghua: FH) of different ages using the MicroResp(TM), phospholipid fatty acid (PLFA), and high-throughput sequencing techniques. Both total PLFAs and glucose-induced respiration suggested more active microorganisms occurred in intermediate cover soils. Microorganisms in all landfill cover soils favored L-malic acid, ketoglutarate, and citric acid. Gram-negative bacterial PLFAs predominated in all samples with the representation of 16:1ω7, 18:1ω7, and cy19:0 in XS and NH sites. Proteobacteria dominated soil microbial phyla across different sites, soil layers, and season samples. Canonical correspondence analysis showed soil pH, dissolved organic C (DOC), As, and total nitrogen (TN) contents significantly influenced the microbial community but TN affected the microbial physiological activities in both summer and winter landfill cover soils.
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Affiliation(s)
- Xi-En Long
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, No. 1799 Jimei Road, Xiamen, 361021, China
- Ningbo Key Lab of Urban Environment Process and Pollution Control, Ningbo Urban Environment Observation and Research Station-NUEORS, Chinese Academy of Sciences, No. 88 Zhong Ke Road, Ningbo, 315830, China
| | - Juan Wang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, No. 1799 Jimei Road, Xiamen, 361021, China
- Ningbo Key Lab of Urban Environment Process and Pollution Control, Ningbo Urban Environment Observation and Research Station-NUEORS, Chinese Academy of Sciences, No. 88 Zhong Ke Road, Ningbo, 315830, China
| | - Ying Huang
- Nanjing Institute of Agricultural Sciences in Jiangsu Hilly Area, No. 6 Xianyin South Road, Qixia District, Nanjing, Jiangsu Province, 210046, China
| | - Huaiying Yao
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, No. 1799 Jimei Road, Xiamen, 361021, China.
- Ningbo Key Lab of Urban Environment Process and Pollution Control, Ningbo Urban Environment Observation and Research Station-NUEORS, Chinese Academy of Sciences, No. 88 Zhong Ke Road, Ningbo, 315830, China.
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Wei XM, Su Y, Zhang HT, Chen M, He R. Responses of methanotrophic activity, community and EPS production to CH4 and O2 concentrations in waste biocover soils. WASTE MANAGEMENT (NEW YORK, N.Y.) 2015; 42:118-127. [PMID: 25921582 DOI: 10.1016/j.wasman.2015.04.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 03/17/2015] [Accepted: 04/05/2015] [Indexed: 06/04/2023]
Abstract
Biocover soils are known to be a good alternative material to mitigate CH4 emissions from landfills to the atmosphere. In this study, 16 treatments with four O2 concentrations (∼0%, 5%, 10% and 21%) and four CH4 concentrations (i.e. 1%, 10%, 20% and 50%) were conducted to estimate extracellular polymeric substances (EPS) production, methanotrophic activity and community in response to CH4 and O2 concentrations in waste biocover soil (WBS). When the CH4 concentration was saturated for CH4 oxidation in the WBS, the continuous exposure of CH4 above the saturated concentrations could not obviously enhance CH4 oxidation activity. In the WBS, extracellular protein (ECP) production was negatively related with the tested CH4 concentrations, while both ECP and extracellular polysaccharides (ECPS) productions were positively related with the tested O2 concentrations. Cloning and terminal restriction fragment length polymorphism analyses showed that type I methanotrophs (Methylocaldum, Methylococcaceae, Methylomicrobium and Methylobacter) and type II methanotrophs (Methylosinus) dominated in the WBS. Among them, Methylocaldum and/or Methylococcaceae were sensitive to low O2 concentrations of ∼0%. Methylobacter had propensity to grow at low O2 concentrations of ∼0% and 5%, while Methylosinus preferred environments with high concentrations of CH4 (⩾10%) and O2 (21%). In the tested five environmental variables of ECPS, O2, EPS, CH4 and ECP, only ECPS and O2 concentrations had significant effect on the methanotrophic communities. These results suggested that O2 concentration in landfill covers should be paid more attention to optimize and sustain CH4 oxidation for mitigating CH4 emission from landfills.
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Affiliation(s)
- Xiao-Meng Wei
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China
| | - Yao Su
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China
| | - Hong-Tao Zhang
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China
| | - Min Chen
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China
| | - Ruo He
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China.
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Eskandari M, Homaee M, Mahmoodi S, Pazira E, Van Genuchten MT. Optimizing landfill site selection by using land classification maps. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:7754-7765. [PMID: 25666474 DOI: 10.1007/s11356-015-4182-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Accepted: 01/28/2015] [Indexed: 06/04/2023]
Abstract
Municipal solid waste disposal is a major environmental concern throughout the world. Proper landfill siting involves many environmental, economic, technical, and sociocultural challenges. In this study, a new quantitative method for landfill siting that reduces the number of evaluation criteria, simplifies siting procedures, and enhances the utility of available land evaluation maps was proposed. The method is demonstrated by selecting a suitable landfill site near the city of Marvdasht in Iran. The approach involves two separate stages. First, necessary criteria for preliminary landfill siting using four constraints and eight factors were obtained from a land classification map initially prepared for irrigation purposes. Thereafter, the criteria were standardized using a rating approach and then weighted to obtain a suitability map for landfill siting, with ratings in a 0-1 domain and divided into five suitability classes. Results were almost identical to those obtained with a more traditional environmental landfill siting approach. Because of far fewer evaluation criteria, the proposed weighting method was much easier to implement while producing a more convincing database for landfill siting. The classification map also considered land productivity. In the second stage, the six best alternative sites were evaluated for final landfill siting using four additional criteria. Sensitivity analyses were furthermore conducted to assess the stability of the obtained ranking. Results indicate that the method provides a precise siting procedure that should convince all pertinent stakeholders.
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Affiliation(s)
- M Eskandari
- Young Researchers and Elites Club, Science and Research Branch, Islamic Azad University, Tehran, Iran
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Mei C, Yazdani R, Han B, Mostafid ME, Chanton J, VanderGheynst J, Imhoff P. Performance of green waste biocovers for enhancing methane oxidation. WASTE MANAGEMENT (NEW YORK, N.Y.) 2015; 39:205-215. [PMID: 25792440 DOI: 10.1016/j.wasman.2015.01.042] [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: 11/25/2014] [Revised: 01/13/2015] [Accepted: 01/30/2015] [Indexed: 06/04/2023]
Abstract
Green waste aged 2 and 24months, labeled "fresh" and "aged" green waste, respectively, were placed in biocover test cells and evaluated for their ability to oxidize methane (CH4) under high landfill gas loading over a 15-month testing period. These materials are less costly to produce than green waste compost, yet satisfied recommended respiration requirements for landfill compost covers. In field tests employing a novel gas tracer to correct for leakage, both green wastes oxidized CH4 at high rates during the first few months of operation - 140 and 200g/m(2)/day for aged and fresh green waste, respectively. Biocover performance degraded during the winter and spring, with significant CH4 generated from anaerobic regions in the 60-80cm thick biocovers. Concurrently, CH4 oxidation rates decreased. Two previously developed empirical models for moisture and temperature dependency of CH4 oxidation in soils were used to test their applicability to green waste. Models accounted for 68% and 79% of the observed seasonal variations in CH4 oxidation rates for aged green waste. Neither model could describe similar seasonal changes for the less stable fresh green waste. This is the first field application and evaluation of these empirical models using media with high organic matter. Given the difficulty of preventing undesired CH4 generation, green waste may not be a viable biocover material for many climates and landfill conditions.
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Affiliation(s)
- Changgen Mei
- Faculty of Geoscience and Environmental Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China; Department of Civil and Environmental Engineering, University of Delaware, Newark, DE 19716, USA
| | - Ramin Yazdani
- Yolo County Planning & Public Works Department, Division of Integrated Waste Management, Woodland, CA 95776, USA; Air Quality Research Center, University of California, Davis, CA 95616, USA
| | - Byunghyun Han
- Department of Civil and Environmental Engineering, University of Delaware, Newark, DE 19716, USA
| | - M Erfan Mostafid
- Department of Civil and Environmental Engineering, University of Delaware, Newark, DE 19716, USA; Now at Terra Pacific Group, Irvine, CA 92618, USA
| | - Jeff Chanton
- Department of Oceanography, Florida State University, Tallahassee, FL 32306, USA
| | - Jean VanderGheynst
- Department of Biological and Agricultural Engineering, University of California, Davis, CA 95616, USA
| | - Paul Imhoff
- Department of Civil and Environmental Engineering, University of Delaware, Newark, DE 19716, USA
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McKain K, Down A, Raciti SM, Budney J, Hutyra LR, Floerchinger C, Herndon SC, Nehrkorn T, Zahniser MS, Jackson RB, Phillips N, Wofsy SC. Methane emissions from natural gas infrastructure and use in the urban region of Boston, Massachusetts. Proc Natl Acad Sci U S A 2015; 112:1941-6. [PMID: 25617375 PMCID: PMC4343086 DOI: 10.1073/pnas.1416261112] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Methane emissions from natural gas delivery and end use must be quantified to evaluate the environmental impacts of natural gas and to develop and assess the efficacy of emission reduction strategies. We report natural gas emission rates for 1 y in the urban region of Boston, using a comprehensive atmospheric measurement and modeling framework. Continuous methane observations from four stations are combined with a high-resolution transport model to quantify the regional average emission flux, 18.5 ± 3.7 (95% confidence interval) g CH4 ⋅ m(-2) ⋅ y(-1). Simultaneous observations of atmospheric ethane, compared with the ethane-to-methane ratio in the pipeline gas delivered to the region, demonstrate that natural gas accounted for ∼ 60-100% of methane emissions, depending on season. Using government statistics and geospatial data on natural gas use, we find the average fractional loss rate to the atmosphere from all downstream components of the natural gas system, including transmission, distribution, and end use, was 2.7 ± 0.6% in the Boston urban region, with little seasonal variability. This fraction is notably higher than the 1.1% implied by the most closely comparable emission inventory.
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Affiliation(s)
- Kathryn McKain
- School of Engineering and Applied Sciences and Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138;
| | - Adrian Down
- Nicholas School of the Environment and Center on Global Change, Duke University, Durham, NC 27708
| | - Steve M Raciti
- Department of Earth and Environment, Boston University, Boston, MA 02215; Department of Biology, Hofstra University, Hempstead, NY 11549
| | - John Budney
- School of Engineering and Applied Sciences and
| | - Lucy R Hutyra
- Department of Earth and Environment, Boston University, Boston, MA 02215
| | | | | | - Thomas Nehrkorn
- Atmospheric and Environmental Research, Inc., Lexington, MA 02421; and
| | | | - Robert B Jackson
- Nicholas School of the Environment and Center on Global Change, Duke University, Durham, NC 27708; School of Earth Sciences, Stanford Woods Institute for the Environment, and Precourt Institute for Energy, Stanford University, Stanford, CA 94305
| | - Nathan Phillips
- Department of Earth and Environment, Boston University, Boston, MA 02215
| | - Steven C Wofsy
- School of Engineering and Applied Sciences and Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138
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Meirhofer M, Piringer G, Rixrath D, Sommer M, Ragossnig AM. Implementing an advanced waste separation step in an MBT plant: assessment of technical, economic and environmental impacts. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2013; 31:35-45. [PMID: 23797300 DOI: 10.1177/0734242x13493958] [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
Heavy fractions resulting from mechanical treatment stages of mechanical-biological waste treatment plants are posing very specific demands with regard to further treatment (large portions of inert and high-caloric components). Based on the current Austrian legal situation such a waste stream cannot be landfilled and must be thermally treated. The aim of this research was to evaluate if an inert fraction generated from this waste stream with advanced separation technologies, two sensor-based [near-infrared spectroscopy (NIR), X-ray transmission (XRT)] and two mechanical systems (wet and dry) is able to be disposed of. The performance of the treatment options for separation was evaluated by characterizing the resulting product streams with respect to purity and yield. Complementing the technical evaluation of the processing options, an assessment of the economic and global warming effects of the change in waste stream routing was conducted. The separated inert fraction was evaluated with regard to landfilling. The remaining high-caloric product stream was evaluated with regard to thermal utilization. The results show that, in principal, the selected treatment technologies can be used to separate high-caloric from inert components. Limitations were identified with regard to the product qualities achieved, as well as to the economic expedience of the treatment options. One of the sensor-based sorting systems (X-ray) was able to produce the highest amount of disposeable heavy fraction (44.1%), while having the lowest content of organic (2.0% C biogenic per kg waste input) components. None of the high-caloric product streams complied with the requirements for solid recovered fuels as defined in the Austrian Ordinance on Waste Incineration. The economic evaluation illustrates the highest specific treatment costs for the XRT (€ 23.15 per t), followed by the NIR-based sorting system (€ 15.67 per t), and the lowest costs for the air separation system (€ 10.79 per t). Within the ecological evaluation it can be shown that the results depend strongly on the higher heating value of the high caloric light fraction and on the content of C biogenic of the heavy fraction. Therefore, the XRT system had the best results for the overall GWP [-14 kg carbon dioxide equivalents (CO2 eq) per t of input waste] and the NIR-based the worst (193 kg CO2 eq per t of input waste). It is concluded that three of the treatment options would be suitable under the specific conditions considered here. Of these, sensor-based sorting is preferable owing to its flexibility.
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Harborth P, Fuss R, Münnich K, Flessa H, Fricke K. Spatial variability of nitrous oxide and methane emissions from an MBT landfill in operation: strong N2O hotspots at the working face. WASTE MANAGEMENT (NEW YORK, N.Y.) 2013; 33:2099-2107. [PMID: 23453435 DOI: 10.1016/j.wasman.2013.01.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 01/16/2013] [Accepted: 01/23/2013] [Indexed: 06/01/2023]
Abstract
Mechanical biological treatment (MBT) is an effective technique, which removes organic carbon from municipal solid waste (MSW) prior to deposition. Thereby, methane (CH4) production in the landfill is strongly mitigated. However, direct measurements of greenhouse gas emissions from full-scale MBT landfills have not been conducted so far. Thus, CH4 and nitrous oxide (N2O) emissions from a German MBT landfill in operation as well as their concentrations in the landfill gas (LFG) were measured. High N2O emissions of 20-200gCO2eq.m(-2)h(-1) magnitude (up to 428mgNm(-2)h(-1)) were observed within 20m of the working face. CH4 emissions were highest at the landfill zone located at a distance of 30-40m from the working face, where they reached about 10gCO2eq.m(-2)h(-1). The MBT material in this area has been deposited several weeks earlier. Maximum LFG concentration for N2O was 24.000ppmv in material below the emission hotspot. At a depth of 50cm from the landfill surface a strong negative correlation between N2O and CH4 concentrations was observed. From this and from the distribution pattern of extractable ammonium, nitrite, and nitrate it has been concluded that strong N2O production is associated with nitrification activity and the occurrence of nitrite and nitrate, which is initiated by oxygen input during waste deposition. Therefore, CH4 mitigation measures, which often employ aeration, could result in a net increase of GHG emissions due to increased N2O emissions, especially at MBT landfills.
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Affiliation(s)
- Peter Harborth
- Department of Waste and Resource Management, Leichtweiß-Institute for Hydraulic Engineering and Water Resources, Technische Universität Braunschweig, Braunschweig, Germany.
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Duan YF, Elsgaard L, Petersen SO. Inhibition of methane oxidation in a slurry surface crust by inorganic nitrogen: an incubation study. JOURNAL OF ENVIRONMENTAL QUALITY 2013; 42:507-515. [PMID: 23673843 DOI: 10.2134/jeq2012.0230] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Livestock slurry is an important source of methane (CH). However, depending on the dry matter content of the slurry, a floating crust may form where methane-oxidizing bacteria (MOB) and CH oxidation activity have been found, suggesting that surface crusts may reduce CH emissions from slurry. However, it is not known how MOB in this environment interact with inorganic nitrogen (N). We studied inhibitory effects of ammonium (NH), nitrate (NO), and nitrite (NO) on potential CH oxidation in a cattle slurry surface crust. At headspace concentrations of 100 and 10,000 ppmv, CH oxidation was assayed at salt concentrations up to 500 mM. First-order rate constants were used to evaluate the strength of inhibition. Nitrite was the most potent inhibitor, reducing methanotrophic activity by up to 70% at only 1 mM NO. Methane-oxidizing bacteria were least sensitive to NO, tolerating up to 30 mM NO at 100 ppmv CH and 50 mM NO at 10,000 ppmv CH without any decline in activity. The inhibition by NH increased progressively, and no range of tolerance was observed. Methane concentrations of 10,000 ppmv resulted in 50- to 100-fold higher specific CH uptake rates than 100 ppmv CH but did not change the inhibition patterns of N salts. In slurry surface crusts, MOB maintained activity at higher concentrations of NH and NO than reported for MOB in soils and sediments, possibly showing adaptation to high N concentrations in the slurry environment. Yet it appears that the effectiveness of surface crusts as CH sinks will depend on inorganic N concentrations.
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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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Lu X, Jordan B, Berge ND. Thermal conversion of municipal solid waste via hydrothermal carbonization: comparison of carbonization products to products from current waste management techniques. WASTE MANAGEMENT (NEW YORK, N.Y.) 2012; 32:1353-1365. [PMID: 22516099 DOI: 10.1016/j.wasman.2012.02.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 02/08/2012] [Accepted: 02/27/2012] [Indexed: 05/31/2023]
Abstract
Hydrothermal carbonization (HTC) is a novel thermal conversion process that may be a viable means for managing solid waste streams while minimizing greenhouse gas production and producing residual material with intrinsic value. HTC is a wet, relatively low temperature (180-350 °C) thermal conversion process that has been shown to convert biomass to a carbonaceous residue referred to as hydrochar. Results from batch experiments indicate HTC of representative waste materials is feasible, and results in the majority of carbon (45-75% of the initially present carbon) remaining within the hydrochar. Gas production during the batch experiments suggests that longer reaction periods may be desirable to maximize the production of energy-favorable products. If using the hydrochar for applications in which the carbon will remain stored, results suggest that the gaseous products from HTC result in fewer g CO(2)-equivalent emissions than the gases associated with landfilling, composting, and incineration. When considering the use of hydrochar as a solid fuel, more energy can be derived from the hydrochar than from the gases resulting from waste degradation during landfilling and anaerobic digestion, and from incineration of food waste. Carbon emissions resulting from the use of the hydrochar as a fuel source are smaller than those associated with incineration, suggesting HTC may serve as an environmentally beneficial alternative to incineration. The type and extent of environmental benefits derived from HTC will be dependent on hydrochar use/the purpose for HTC (e.g., energy generation or carbon storage).
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Affiliation(s)
- Xiaowei Lu
- Department of Civil and Environmental Engineering, University of South Carolina, 300 Main Street, Columbia, SC 29208, USA
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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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Adams BL, Besnard F, Bogner J, Hilger H. Bio-tarp alternative daily cover prototypes for methane oxidation atop open landfill cells. WASTE MANAGEMENT (NEW YORK, N.Y.) 2011; 31:1065-1073. [PMID: 21354776 DOI: 10.1016/j.wasman.2011.01.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Revised: 12/11/2010] [Accepted: 01/04/2011] [Indexed: 05/30/2023]
Abstract
Final landfill covers are highly engineered to prevent methane release into the atmosphere. However, methane production begins soon after waste placement and is an unaddressed source of emissions. The methane oxidation capacity of methanotrophs embedded in a "bio-tarp" was investigated as a means to mitigate methane release from open landfill cells. The bio-tarp would also serve as an alternative daily cover during routine landfill operation. Evaluations of nine synthetic geotextiles identified two that would likely be suitable bio-tarp components. Pilot tarp prototypes were tested in continuous flow systems simulating landfill gas conditions. Multilayered bio-tarp prototypes consisting of alternating layers of the two geotextiles were found to remove 16% of the methane flowing through the bio-tarp. The addition of landfill cover soil, compost, or shale amendments to the bio-tarp increased the methane removal up to 32%. With evidence of methane removal in a laboratory bioreactor, prototypes were evaluated at a local landfill using flux chambers installed atop intermediate cover at a landfill. The multilayered bio-tarp and amended bio-tarp configurations were all found to decrease landfill methane flux; however, the performance efficacy of bio-tarps was not significantly different from controls without methanotrophs. Because highly variable methane fluxes at the field site likely confounded the test results, repeat field testing is recommended under more controlled flux conditions.
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Affiliation(s)
- Bryn L Adams
- Department of Biology, University of North Carolina at Charlotte, NC, USA
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