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Liang CW, Zheng ZC, Chen TN. Monitoring landfill volatile organic compounds emissions by an uncrewed aerial vehicle platform with infrared and visible-light cameras, remote monitoring, and sampling systems. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 365:121575. [PMID: 38959775 DOI: 10.1016/j.jenvman.2024.121575] [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: 05/10/2024] [Revised: 06/20/2024] [Accepted: 06/21/2024] [Indexed: 07/05/2024]
Abstract
An uncrewed aerial vehicle (UAV) platform equipped with dual imaging cameras, a gas sampling system, and a remote synchronous monitoring system was developed to sample and analyze volatile organic compounds (VOCs) emitted from landfills. The remote synchronous monitoring system provided real-time video to administrators with specific permissions to assist in identifying sampling sites within extensive landfill areas. The sampling system included four kits capable of collecting samples from different locations during a single flight mission. Each kit comprised a 1 L Tedlar bag for measuring landfill VOC concentrations according to the TO-15 method prescribed by the US Environmental Protection Agency. The air sample was introduced into a Tedlar bag via pumping. A known volume of the sample was subsequently concentrated using a solid multisorbent concentrator. Following this, the sample underwent cold trap concentration and thermal desorption. The concentrated sample was then transferred to a chromatography-mass spectrometry system for separation and analysis. Since the anaerobic catabolism of organic waste is exothermic and emits VOCs, this study employed UAV thermal imaging to locate principal emission sources for sampling. Visible-light imaging helped identify newer or older landfill sections, aiding in the selection of appropriate sampling sites, particularly when surfaces were thermally disturbed by solar radiation. Field measurements were conducted under three meteorological conditions: sunny morning, cirrus morning, and thin cloud evening (2 h after sunset), identifying 119, 122, and 111 chemical species respectively. The sequence of total VOC concentrations measured correlated with the meteorological conditions as follows: cirrus morning > thin cloud evening > sunny morning. The results indicated that ambient temperature and global solar radiation significantly influenced daytime gas emissions from landfills. Evening thermal images, unaffected by solar heating, facilitated more accurate identification of major VOC emission points, resulting in higher VOC concentrations compared to those recorded in the sunny morning. VOCs from the landfill were categorized into nine organic groups: alkanes, alkenes, carbonyls, aromatics, alcohols, esters, ethers, organic oxides, and others. The classification was based on carbon-containing compounds (Cn, where the compound contains n carbon atoms). Alkanes were predominant in terms of Cn presence, followed by alcohols and carbonyls. Among the organic groups, organic oxides, particularly 2-heptyl-1,3-dioxolane, exhibited the highest concentrations, succeeded by alkenes. Sampling under cloudy conditions or in the evening is recommended to minimize the effects of surface temperature anomalies caused by solar radiation, which vary due to differences in land composition.
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Affiliation(s)
- Chen-Wei Liang
- Master Program in UAV Application and Precision Agriculture, National Ilan University, Yilan, Taiwan; Department of Biomechatronic Engineering, National Ilan University, Yilan, Taiwan.
| | - Zhong-Chun Zheng
- Department of Biomechatronic Engineering, National Ilan University, Yilan, Taiwan
| | - Ting-Nong Chen
- Master Program in UAV Application and Precision Agriculture, National Ilan University, Yilan, Taiwan
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Xie Y, Wang H, Chen Y, Guo Y, Wang C, Cui H, Xue J. Water retention and hydraulic properties of a natural soil subjected to microplastic contaminations and leachate exposures. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 901:166502. [PMID: 37619730 DOI: 10.1016/j.scitotenv.2023.166502] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/20/2023] [Accepted: 08/21/2023] [Indexed: 08/26/2023]
Abstract
The influences of microplastics (MPs) contamination on soils have been extensively studied recently. Most of previous studies focus on saturated hydraulic conductivities and water retention of loose soils under laboratory conditions. The effects of MPs on the hydraulic properties of compacted soils for engineering purposes have not been well understood. This paper presents the laboratory investigation of water retention capacity, saturated (ksat) and unsaturated (kθ) hydraulic conductivities of a compacted natural soil contaminated by MPs and exposed to fresh, medium-aged, and stabilized leachates. The saturated (kg) and unsaturated air conductivities (kgθ) are calculated. The MPs with maximum particle sizes of 500, 150 and 50 μm were added to soils to obtain samples with mass ratios of 0.5, 1.0, 2.0, and 5.0 %, respectively. Under similar ranges of dry densities, permeation of fresh leachates decreases ksat of the compacted soils by 30 % while exposure to stabilized leachates increases ksat by 10 %, due to the viscosities of liquids. The flow channel properties of the compacted soils contaminated with different sizes and concentrations of MPs vary. The most complex flow channel can be found in samples with 5 % 50 μm MPs. The inclusions of MPs decrease residual moisture contents of the compacted soils regardless of MP sizes and percentages. The effects of MPs on air-entry pressures and parameter n depend on the sizes of MPs. The kθ (kgθ) of compacted soils with MPs depend on the combined effects of ksat (kg) and tortuosity parameter (l). Though l ranges from -0.85 to 2.12 with different levels of MP exposures, it does not have a significant influence on the relative hydraulic (kθ/ksat) and air conductivities (kgθ/kg) of the compacted soils. Future studies can focus on the long-term hydraulic properties of soils under MP contamination.
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Affiliation(s)
- Yuekai Xie
- School of Engineering and Technology, University of New South Wales, Canberra, ACT 2612, Australia
| | - Hongxu Wang
- School of Engineering and Technology, University of New South Wales, Canberra, ACT 2612, Australia
| | - Yue Chen
- School of Engineering and Technology, University of New South Wales, Canberra, ACT 2612, Australia
| | - Yingying Guo
- Civil Branch, Infrastructure Delivery Partner, Major Projects Canberra, Canberra, ACT 2606, Australia
| | - Chenman Wang
- Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, College of Civil and Transportation Engineering, Shenzhen University, Shenzhen 518060, Guangdong, China
| | - Hanwen Cui
- School of Engineering and Technology, University of New South Wales, Canberra, ACT 2612, Australia; Queensland Department of Transport and Main Roads, South Coast Region, Nerang, QLD 4211, Australia
| | - Jianfeng Xue
- School of Engineering and Technology, University of New South Wales, Canberra, ACT 2612, Australia.
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Malmir T, Héroux M, Lagos D, Eicker U. Assessment of landfill gas storage and application regarding energy management: A case study in the province of Quebec, Canada. WASTE MANAGEMENT (NEW YORK, N.Y.) 2023; 171:155-162. [PMID: 37659122 DOI: 10.1016/j.wasman.2023.08.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 08/18/2023] [Accepted: 08/23/2023] [Indexed: 09/04/2023]
Abstract
Landfills are extensively applied to dispose of municipal solid wastes in developed and developing countries. Landfill gas generation from biodegradable organic wastes can be collected and converted to energy. When the gas collection system is shutdown, some of this gas can accumulate and be stored inside the landfill. Using the gas storage capacity of the landfill gets a better management of the landfill site because the collected stored gas could transform the landfill into a cheap gas storage system to provide short-term energy and use the energy when needed. This novel study analyzes the stored methane using the gas collection data of a landfill in Quebec province, Canada, for modulating energy production from landfill gas. Twenty episodes of the gas collection system's shutdown and restart as well as different gas flow durations were studied. The results showed that the collected stored methane is accumulated in an average of 2.5 h. Additionally, the collected stored methane represents 10.5% of landfill gas flow. Although the results are site-specific, the methodology of this paper can be used on other landfill sites with similar size and collection conditions. Designing new landfills could take into consideration some elements to enhance gas storage capacity. For instance, designing landfill daily covers with more granular materials and higher porosities can be the next step to enhance the landfill as a gas storage system during shutdowns.
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Affiliation(s)
- Tahereh Malmir
- Canada Excellence Research Chair Next Generation Cities, Gina Cody School of Engineering and Computer Science, Concordia University, H3G 1M8 Montreal, Canada; Department of Building, Civil and Environmental Engineering, Concordia University, H3G 1M8 Montreal, Canada.
| | - Martin Héroux
- Biothermica Technologies Inc., H2L 1J6 Montreal, Canada.
| | - Daniel Lagos
- Biothermica Technologies Inc., H2L 1J6 Montreal, Canada.
| | - Ursula Eicker
- Canada Excellence Research Chair Next Generation Cities, Gina Cody School of Engineering and Computer Science, Concordia University, H3G 1M8 Montreal, Canada; Department of Building, Civil and Environmental Engineering, Concordia University, H3G 1M8 Montreal, Canada.
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Wang YN, Wang Q, Li Y, Wang H, Gao Y, Sun Y, Wang B, Bian R, Li W, Zhan M. Impact of incineration slag co-disposed with municipal solid waste on methane production and methanogens ecology in landfills. BIORESOURCE TECHNOLOGY 2023; 377:128978. [PMID: 36990329 DOI: 10.1016/j.biortech.2023.128978] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/24/2023] [Accepted: 03/26/2023] [Indexed: 06/19/2023]
Abstract
Co-landfill of incineration slag and municipal solid waste (MSW) is a main method for disposal of slag, and it has the potential of promoting methane (CH4) production and accelerating landfill stabilization. Four simulated MSW landfill columns loaded with different amount of slag (A, 0%; B, 5%; C, 10%; D, 20%) were established, and the CH4 production characteristics and methanogenic mechanisms were investigated. The maximum CH4 concentration in columns A, B, C and D was 10.8%, 23.3%, 36.3% and 34.3%, respectively. Leachate pH and refuse pH were positively correlated with CH4 concentration. Methanosarcina was the dominant genus with abundance of 35.1%∼75.2% and it was positively correlated with CH4 concentration. CO2-reducing and acetoclastic methanogenesis were the main types of methanogenesis pathway, and the methanogenesis functional abundance increased with slag proportion during stable methanogenesis process. This research can help understanding the impact of slag on CH4 production characteristics and microbiological mechanisms in landfills.
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Affiliation(s)
- Ya-Nan Wang
- Qingdao Solid Waste Pollution Control and Resource Engineering Research Center, Qingdao University of Technology, School of Environmental and Municipal Engineering, Qingdao, China
| | - Qingzhao Wang
- Qingdao Solid Waste Pollution Control and Resource Engineering Research Center, Qingdao University of Technology, School of Environmental and Municipal Engineering, Qingdao, China
| | - Yahui Li
- Qingdao Solid Waste Pollution Control and Resource Engineering Research Center, Qingdao University of Technology, School of Environmental and Municipal Engineering, Qingdao, China
| | - Huawei Wang
- Qingdao Solid Waste Pollution Control and Resource Engineering Research Center, Qingdao University of Technology, School of Environmental and Municipal Engineering, Qingdao, China.
| | - Ying Gao
- Qingdao Solid Waste Pollution Control and Resource Engineering Research Center, Qingdao University of Technology, School of Environmental and Municipal Engineering, Qingdao, China
| | - Yingjie Sun
- Qingdao Solid Waste Pollution Control and Resource Engineering Research Center, Qingdao University of Technology, School of Environmental and Municipal Engineering, Qingdao, China
| | - Bingpeng Wang
- Qingdao Solid Waste Pollution Control and Resource Engineering Research Center, Qingdao University of Technology, School of Environmental and Municipal Engineering, Qingdao, China
| | - Rongxing Bian
- Qingdao Solid Waste Pollution Control and Resource Engineering Research Center, Qingdao University of Technology, School of Environmental and Municipal Engineering, Qingdao, China
| | - Weihua Li
- Qingdao Solid Waste Pollution Control and Resource Engineering Research Center, Qingdao University of Technology, School of Environmental and Municipal Engineering, Qingdao, China
| | - Meili Zhan
- Qingdao Solid Waste Disposal Co LTD, China
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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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