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González-Cortés JJ, Lamprea-Pineda PA, Valle A, Ramírez M, Van Langenhove H, Demeestere K, Walgraeve C. Effect of toluene on siloxane biodegradation and microbial communities in biofilters. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 186:119-129. [PMID: 38875913 DOI: 10.1016/j.wasman.2024.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 05/15/2024] [Accepted: 06/05/2024] [Indexed: 06/16/2024]
Abstract
The removal of volatile methyl siloxanes (VMS) from landfill biogas is crucial for clean energy utilization. VMS are usually found together with aromatic compounds in landfill biogas of which toluene is the major representative. In the present study, two biofilters (BFs) packed with either woodchips and compost (WC) or perlite (PER) were used to study the (co-) removal of octamethyltrisiloxane (L3) and octamethylcyclotetrasiloxane (D4) from gas in presence and absence of toluene, used as a representative aromatic compound. The presence of low inlet toluene concentrations (315 ± 19 - 635 ± 80 mg toluene m-3) enhanced the VMS elimination capacity (EC) in both BFs by a factor of 1.8 to 12.6. The highest removal efficiencies for D4 (57.1 ± 1.1 %; EC = 0.12 ± 0.01 gD4 m-3 h-1) and L3 (52.0 ± 0.6 %; EC = 0.23 ± 0.01 gL3 m-3 h-1) were observed in the BF packed with WC. The first section of the BFs (EBRT = 9 min), where toluene was (almost) completely removed, accounted for the majority (87.7 ± 0.6 %) of the total VMS removal. Microbial analysis revealed the impact of VMS and toluene in the activated sludge, showing a clear selection for certain genera in samples influenced by VMS in the presence (X2) or absence (X1) of toluene, such as Pseudomonas (X1 = 0.91 and X2 = 12.0 %), Sphingobium (X1 = 0.09 and X2 = 4.04 %), Rhodococcus (X1 = 0.42 and X2 = 3.91 %), and Bacillus (X1 = 7.15 and X2 = 3.84 %). The significant maximum EC values obtained by the BFs (0.58 gVMS m-3 h-1) hold notable significance in a combined system framework as they could enhance the longevity of traditional physicochemical methods to remove VMS like activated carbon in diverse environmental scenarios.
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Affiliation(s)
- J J González-Cortés
- Department of Chemical Engineering and Food Technologies, Wine and Agrifood Research Institute (IVAGRO), Faculty of Sciences, University of Cadiz, Cádiz, Spain; Research Group Environmental Organic Chemistry and Technology (EnVOC), Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium.
| | - P A Lamprea-Pineda
- Research Group Environmental Organic Chemistry and Technology (EnVOC), Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - A Valle
- Department of Biomedicine, Biotechnology and Public Health-Biochemistry and Molecular Biology, Campus Universitario de Puerto Real, University of Cadiz, Cadiz, Spain
| | - M Ramírez
- Department of Chemical Engineering and Food Technologies, Wine and Agrifood Research Institute (IVAGRO), Faculty of Sciences, University of Cadiz, Cádiz, Spain
| | - H Van Langenhove
- Research Group Environmental Organic Chemistry and Technology (EnVOC), Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - K Demeestere
- Research Group Environmental Organic Chemistry and Technology (EnVOC), Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - C Walgraeve
- Research Group Environmental Organic Chemistry and Technology (EnVOC), Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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Merouani EFO, Ferdowsi M, Buelna G, Jones JP, Benyoussef EH, Malhautier L, Heitz M. Exploring the potential of biofiltration for mitigating harmful gaseous emissions from small or old landfills: a review. Biodegradation 2024; 35:469-491. [PMID: 38748305 DOI: 10.1007/s10532-024-10082-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 04/13/2024] [Indexed: 07/14/2024]
Abstract
Landfills are widely employed as the primary means of solid waste disposal. However, this practice generates landfill gas (LFG) which contains methane (CH4), a potent greenhouse gas, as well as various volatile organic compounds and volatile inorganic compounds. These emissions from landfills contribute to approximately 25% of the total atmospheric CH4, indicating the imperative need to valorize or treat LFG prior to its release into the atmosphere. This review first aims to outline landfills, waste disposal and valorization, conventional gas treatment techniques commonly employed for LFG treatment, such as flares and thermal oxidation. Furthermore, it explores biotechnological approaches as more technically and economically feasible alternatives for mitigating LFG emissions, especially in the case of small and aged landfills where CH4 concentrations are often below 3% v/v. Finally, this review highlights biofilters as the most suitable biotechnological solution for LFG treatment and discusses several advantages and challenges associated with their implementation in the landfill environment.
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Affiliation(s)
- El Farouk Omar Merouani
- Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, Québec, J1K 2R1, Canada
| | - Milad Ferdowsi
- Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, Québec, J1K 2R1, Canada
| | - Gerardo Buelna
- Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, Québec, J1K 2R1, Canada
| | - J Peter Jones
- Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, Québec, J1K 2R1, Canada
| | - El-Hadi Benyoussef
- Laboratoire de Valorisation des Énergies Fossiles, École Nationale Polytechnique, 10 Avenue Hassan Badi El Harrach, BP182, 16200, Algiers, Algeria
| | - Luc Malhautier
- Laboratoire des Sciences des Risques, IMT Mines Alès, 6 avenue de Clavières, 30319, Alès Cedex, France
| | - Michèle Heitz
- Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, Québec, J1K 2R1, Canada.
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Feng F, Yang Y, Liu Q, Wu S, Yun Z, Xu X, Jiang Y. Insights into the characteristics of changes in dissolved organic matter fluorescence components on the natural attenuation process of toluene. JOURNAL OF HAZARDOUS MATERIALS 2024; 476:134952. [PMID: 38944985 DOI: 10.1016/j.jhazmat.2024.134952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 06/10/2024] [Accepted: 06/16/2024] [Indexed: 07/02/2024]
Abstract
Natural attenuation (NA) is of great significance for the remediation of contaminated groundwater, and how to identify NA patterns of toluene in aquifers more quickly and effectively poses an urgent challenge. In this study, the NA of toluene in two typical soils was conducted by means of soil column experiment. Based on column experiments, dissolved organic matter (DOM) was rapidly identified using fluorescence spectroscopy, and the relationship between DOM and the NA of toluene was established through structural equation modeling analysis. The adsorption rates of toluene in clay and sandy soil were 39 % and 26 %, respectively. The adsorption capacity and total NA capacity of silty clay were large. The occurrence of fluorescence peaks of protein-like components and specific products indicated the occurrence of biodegradation. Arenimonas, Acidovorax and Brevundimonas were the main degrading bacteria identified in Column A, while Pseudomonas, Azotobacter and Mycobacterium were the main ones identified in Column B. The pH, ORP, and Fe(II) were the most important factors affecting the composition of microbial communities, which in turn affected the NA of toluene. These results provide a new way to quickly identify NA of toluene.
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Affiliation(s)
- Fan Feng
- College of Water Sciences, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Yu Yang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Qiyuan Liu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Shuxuan Wu
- College of Water Sciences, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Zhichao Yun
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Xiangjian Xu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Yonghai Jiang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
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4
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Shangjie C, Yongqiong W, Fuqing X, Zhilin X, Xiaoping Z, Xia S, Juan L, Tiantao Z, Shibin W. Synergistic effects of vegetation and microorganisms on enhancing of biodegradation of landfill gas. ENVIRONMENTAL RESEARCH 2023; 227:115804. [PMID: 37003556 DOI: 10.1016/j.envres.2023.115804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 03/20/2023] [Accepted: 03/29/2023] [Indexed: 05/08/2023]
Abstract
The uncontrolled release of landfill gas represents a significant hazard to both human health and ecological well-being. However, the synergistic interactions of vegetation and microorganisms can effectively mitigate this threat by removing pollutants. This study provides a comprehensive review of the current status of controlling landfill gas pollution through the process of revegetation in landfill cover. Our survey has identified several common indicator plants such as Setaria faberi, Sarcandra glabra, and Fraxinus chinensis that grow in covered landfill soil. Local herbaceous plants possess stronger tolerance, making them ideal for the establishment of closed landfills. Moreover, numerous studies have demonstrated that cover plants significantly promote methane oxidation, with an average oxidation capacity twice that of bare soil. Furthermore, we have conducted an analysis of the interrelationships among vegetation, landfill gas, landfill cover soil, and microorganisms, thereby providing a detailed understanding of the potential for vegetation restoration in landfill cover. Additionally, we have summarized studies on the rhizosphere effect and have deduced the mechanisms through which plants biodegrade methane and typical non-methane pollutants. Finally, we have suggested future research directions to better control landfill gas using vegetation and microorganisms.
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Affiliation(s)
- Chen Shangjie
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing, 400054, China
| | - Wang Yongqiong
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing, 400054, China
| | - Xu Fuqing
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing, 400054, China
| | - Xing Zhilin
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing, 400054, China.
| | - Zhang Xiaoping
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing, 400054, China
| | - Su Xia
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing, 400054, China
| | - Li Juan
- Chongqing Academy of Chinese Materia Medica, Chongqing, 400060, China
| | - Zhao Tiantao
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing, 400054, China
| | - Wan Shibin
- School of Electrical and Electronic Engineering, Chongqing University of Technology, Chongqing, 400054, China
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5
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Pan Q, Liu QY, Zheng J, Li YH, Xiang S, Sun XJ, He XS. Volatile and semi-volatile organic compounds in landfill gas: Composition characteristics and health risks. ENVIRONMENT INTERNATIONAL 2023; 174:107886. [PMID: 36989764 DOI: 10.1016/j.envint.2023.107886] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 03/11/2023] [Accepted: 03/15/2023] [Indexed: 06/19/2023]
Abstract
Gas emitted from landfills contains a large quantity of volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs), some of which are carcinogenic, teratogenic, and mutagenic, thereby posing a serious threat to the health of landfill workers and nearby residents. However, the global hazards of VOCs and SVOCs in landfill gas to human health remain unclear. To quantify the global risk distributions of these pollutants, we collected the composition and concentration data of VOCs and SVOCs from 72 landfills in 20 countries from the core database of Web of Science and assessed their human health risks as well as analyzed their influencing factors. Organic compounds in landfill gas were found to primarily result from the biodegradation of natural organic waste or the emissions and volatilization of chemical products, with the concentration range of 1 × 10-1-1 × 106 μg/m3. The respiratory system, in particular, lung was the major target organ of VOCs and SVOCs, with additional adverse health impacts ranging from headache and allergies to lung cancer. Aromatic and halogenated compounds were the primary sources of health risk, while ethyl acetate and acetone from the biodegradation of natural organic waste also exceeded the acceptable levels for human health. Overall, VOCs and SVOCs affected residents within 1,000 m of landfills. Air temperature, relative humidity, air pressure, wind direction, and wind speed were the major factors that influenced the health risks of VOCs and SVOCs. Currently, landfill risk assessments of VOCs and SVOCs are primarily based on respiratory inhalation, with health risks due to other exposure routes remaining poorly elucidated. In addition, potential health risks due to the transport and transformation of landfill gas emitted into the atmosphere should be further studied.
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Affiliation(s)
- Qi Pan
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; College of Environmental Science and Engineering, Guilin University of Technology, Guilin 541000, China
| | - Qing-Yu Liu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Jing Zheng
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; College of Environmental Science and Engineering, Guilin University of Technology, Guilin 541000, China
| | - Yan-Hong Li
- College of Environmental Science and Engineering, Guilin University of Technology, Guilin 541000, China
| | - Song Xiang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Xiao-Jie Sun
- College of Environmental Science and Engineering, Guilin University of Technology, Guilin 541000, China
| | - Xiao-Song He
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
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6
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Yasar A, Basit S, Tabinda AUB, Ali A, Naqvi SUEK, Nizami AS, Naqvi SLH, Mahmood S, Tanveer R. Evaluation of operational and financial viability models of combined landfill site for intermediate cities in Pakistan. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:1825-1840. [PMID: 35921015 DOI: 10.1007/s11356-022-22240-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
This study aims to evaluate municipal landfill sites' operational and financial viability, waste amount and characterization, primary and secondary collection systems, revenue generation from MSW, vehicle routing, and age of landfill sites located in Akhtarabad, Sahiwal Division. Three operational and financial models were developed to calculate cost/ton value based on obtained data. The obtained results indicate that the cost/ton values for models are the following: 20.01 USD for Model-1, 8.96 USD Model-2, and Model-3 is about 10.23 USD. The waste characterization represented waste consisting of compostable (57%), recyclable (10%), Refuse Derived Fuel (RDF) (12%), earth fill (20%), and disposable material (1%). Revenue/ton of municipal solid waste was about 19.47 USD, and according to cost-benefit analysis, the cost of Model-1 was higher than the benefit. In contrast, the costs of Model-2 and Model-3 were found to be lower than the revenue/ton. However, the waste collection efficiency of Model-1 was greater than both remaining models. The study concluded that utilizing all generated waste, only 21% of waste is dumped at the landfill site. It will reduce the area required for landfill sites from 431437 to 90602 m2 for the next 10 years and increase the age of landfill sites by over 20 years. It is recommended that the reuse of municipal solid waste and implementation of the no waste to landfill model would surely save money, land, and fuel, and it will also increase the age of landfill sites.
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Affiliation(s)
- Abdullah Yasar
- Sustainable Development Study Centre, Government College University, Lahore, 54000, Pakistan.
| | - Salman Basit
- Sustainable Development Study Centre, Government College University, Lahore, 54000, Pakistan
| | - Amt-Ul Bari Tabinda
- Sustainable Development Study Centre, Government College University, Lahore, 54000, Pakistan
| | | | | | - Abdul-Sattar Nizami
- Sustainable Development Study Centre, Government College University, Lahore, 54000, Pakistan
| | | | - Shakeel Mahmood
- Department of Geography, Government College University, Lahore, 54000, Pakistan
| | - Rameesha Tanveer
- Sustainable Development Study Centre, Government College University, Lahore, 54000, Pakistan
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7
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Doyle MG, Odenkirk MT, Stewart AK, Nelson JP, Baker ES, De La Cruz F. Assessing the Fate of Dissolved Organic Compounds in Landfill Leachate and Wastewater Treatment Systems. ACS ES&T WATER 2022; 2:2502-2509. [PMID: 36911356 PMCID: PMC10002909 DOI: 10.1021/acsestwater.2c00320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Landfill leachate and municipal wastewater are major sources of chemical pollutants that contaminate our drinking water sources. Evaluating the dissolved organic chemical composition in wastewater treatment plants is therefore essential to understand how the discharge impacts the environment, wildlife, and human health. In this study, we utilized a nontargeted analysis method coupling liquid chromatography and tandem mass spectrometry (LC-MS/MS) to analyze chemical features at different points along two landfill leachate treatment plants (LLTPs) and two municipal wastewater treatment plants (WWTPs) in the Southeastern United States. Significant feature differences were observed for the WWTPs where activated sludge clarification was employed versus the LLTPs utilizing reverse osmosis. Specifically, even though both LLTPs had the largest number of features in their influent water, their effluent following reverse osmosis yielded a lower number of features than the WWTPs. Additionally, the clarification processes of each WWTP exhibited different efficiencies as chemical disinfection removed more features than UV disinfection. Feature identification was then made using the LC, MS, and MS/MS information. Analysis of the identified molecules showed that lipids were the most effectively removed from all plants, while alkaloid and organic nitrogen compounds were the most recalcitrant.
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Affiliation(s)
- Michael G Doyle
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Melanie T Odenkirk
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Allison K Stewart
- Department of Chemistry and Molecular Education, Technology, and Research Innovation Center (METRIC), North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Jacob P Nelson
- Department of Chemical and Biomolecular Engineering North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Erin S Baker
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 2769S, United States
| | - Florentino De La Cruz
- Department of Civil, Construction and Environmental Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
- Present Address: Environmental and Ecological Engineering Purdue University Potter Engineering Center, 500 Central Drive, West Lafayette, IN 47907
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8
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Wang Q, Gu X, Tang S, Mohammad A, Singh DN, Xie H, Chen Y, Zuo X, Sun Z. Gas transport in landfill cover system: A critical appraisal. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 321:116020. [PMID: 36104890 DOI: 10.1016/j.jenvman.2022.116020] [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: 05/20/2022] [Revised: 08/10/2022] [Accepted: 08/12/2022] [Indexed: 06/15/2023]
Abstract
Landfill gas (LFG) emission is gaining more attention from the scientific fraternity and policymakers recently due to its threat to the atmosphere and human health of the populace living in surrounding premises. Though landfill cover (LFC) (viz., daily, intermittent and final cover) is widely used by landfill operators to mitigate or reduce these emissions, their overall performance is still under question. A critical analysis of available literature, primarily pertaining to (i) the composition of the landfill gases and their migration in the LFC system, (ii) experimental and mathematical investigations of the transport mechanism of gas and (iii) the impact of additives to cover soils on transport and fate of gas, has been conducted and presented in this manuscript. Investigation of the efficiency of modified soil was mainly focused on laboratory test. More field tests and application of amended cover soils should be conducted and promoted further. Studies on nitrous oxide and emerging pollutants, including poly-fluoroalkyl substances transport in landfill cover system are limited and need further research. The transport mechanisms of these unconventional contaminants should be considered regarding the selection of LFC materials including geomembrane and geosynthetic clay liners. The existing analytical and numerical models can provide a basic understanding of LFG transport mechanisms and are able to predict the migration behaviour of LFG; however, there are still knowledge gaps concerning the interaction between different species of the gas molecule when modeling multi-component gas transport. Gas transport through fractured cover should also be considered when evaluating LFG emission in the future. Simplified design method for landfill cover system regarding LFG emission based on analytical models should be proposed. Overall, mathematical models combined with experiments can facilitate more visualized and intensive insights, which would be instrumental in devising climate adaptive landfill covers.
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Affiliation(s)
- Qiao Wang
- School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, 230009, China; Center for Balance Architecture, Zhejiang University, 148 Tianmushan Road, Hangzhou, 310007, China
| | - Xiting Gu
- College of Civil Engineering and Architecture, Zhejiang University, 866 Yuhangtang Rd., Hangzhou, 310058, China; Architectural Design and Research Institute of Zhejiang University Co. Ltd, 148 Tianmushan Road, Hangzhou, China
| | - Suqin Tang
- Hangzhou Environmental Group, 138-1 Linban Road, Hangzhou, 310022, China
| | - Arif Mohammad
- Department of Civil Engineering, Indian Institute of Technology Bombay, Mumbai, 400076, India
| | - Devendra Narain Singh
- Department of Civil Engineering, Indian Institute of Technology Bombay, Mumbai, 400076, India
| | - Haijian Xie
- Center for Balance Architecture, Zhejiang University, 148 Tianmushan Road, Hangzhou, 310007, China; College of Civil Engineering and Architecture, Zhejiang University, 866 Yuhangtang Rd., Hangzhou, 310058, China.
| | - Yun Chen
- Center for Balance Architecture, Zhejiang University, 148 Tianmushan Road, Hangzhou, 310007, China; Architectural Design and Research Institute of Zhejiang University Co. Ltd, 148 Tianmushan Road, Hangzhou, China
| | - Xinru Zuo
- Center for Balance Architecture, Zhejiang University, 148 Tianmushan Road, Hangzhou, 310007, China; College of Civil Engineering and Architecture, Zhejiang University, 866 Yuhangtang Rd., Hangzhou, 310058, China
| | - Zhilin Sun
- Ocean College, Zhejiang University, Zheda Road, Zhoushan, 316021, China; College of Hydraulic Engineering and Architecture, Tarim University, Alaer, 843300, China
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9
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Wang Y, Chen Z, Ma J, Wang J, Li L. Migration and transformation of main components during perishable waste bio-drying process. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 319:115720. [PMID: 35853308 DOI: 10.1016/j.jenvman.2022.115720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 07/05/2022] [Accepted: 07/09/2022] [Indexed: 06/15/2023]
Abstract
Bio-drying can significantly reduce the moisture content of waste. The factors, functional microorganisms, and the transformation of main components were investigated during bio-drying of perishable waste. This study provides a scientific basis for the improvement of the bio-drying process and the necessity for secondary pollutant control. Reaction temperature and microbial biomass were main factors during the bio-drying process. The ideal bio-drying conditions included an initial temperature above 20 °C, intermittent ventilation, and appropriate microbial inoculation. The main microorganisms included Alcaligenes, Aquamicrobium, and Brevundimonas. From each gram of the carbonaceous, nitrogenous, sulfur-containing compounds, and phosphorus-containing substances in the perishable waste, approximately 0.74 g, 0.66 g, 0.40 g, and 0.94 g, respectively, were transferred as gas-phase products; consisting mainly of ammonia and volatile organic compounds: 2-heptanone, dimethyl heptanone, and benzene. In the leachate, the respective amounts of the carbonaceous, nitrogenous, sulfur-containing compounds, and phosphorus-containing substances were 3.20 × 10-3 g, 4.08 × 10-3 g, 0.33 g, and 9.52 × 10-3 g, while those of the residual substances remaining in solid were 0.26 g, 0.33 g, 0.28 g, and 0.05 g.
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Affiliation(s)
- Ying Wang
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China.
| | - Zexiang Chen
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, PR China.
| | - Jiawei Ma
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China.
| | - Jun Wang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, PR China.
| | - Lin Li
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China; National Engineering Laboratory for VOCs Pollution Control Material & Technology, University of Chinese Academy of Sciences, Beijing, 101408, PR China.
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10
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Xie H, Zuo X, Chen Y, Yan H, Ni J. Numerical model for static chamber measurement of multi-component landfill gas emissions and its application. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:74225-74241. [PMID: 35635673 PMCID: PMC9550682 DOI: 10.1007/s11356-022-20951-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 05/16/2022] [Indexed: 06/02/2023]
Abstract
The quantitative assessment of landfill gas emissions is essential to assess the performance of the landfill cover and gas collection system. The relative error of the measured surface emission of landfill gas may be induced by the static flux chamber technique. This study aims to quantify effects of the size of the chamber, the insertion depth, pressure differential on the relative errors by using an integrated approach of in situ tests, and numerical modeling. A field experiment study of landfill gas emission is conducted by using a static chamber at one landfill site in Xi'an, Northwest China. Additionally, a two-dimensional axisymmetric numerical model for multi-component gas transport in the soil and the static chamber is developed based on the dusty-gas model (DGM). The proposed model is validated by the field data obtained in this study and a set of experimental data in the literature. The results show that DGM model has a better capacity to predict gas transport under a wider range of permeability compared to Blanc's method. This is due to the fact that DGM model can explain the interaction among gases (e.g., CH4, CO2, O2, and N2) and the Knudsen diffusion process while these mechanisms are not included in Blanc's model. Increasing the size and the insertion depth of static chambers can reduce the relative error for the flux of CH4 and CO2. For example, increasing the height of chambers from 0.55 to 1.1 m can decrease relative errors of CH4 and CO2 flux by 17% and 18%, respectively. Moreover, we find that gas emission fluxes for the case with positive pressure differential (∆Pin-out) are greater than that of the case without considering pressure fluctuations. The Monte Carlo method was adopted to carry out the statistical analysis for quantifying the range of relative errors. The agreement of the measured field data and predicted results demonstrated that the proposed model has the capacity to quantify the emission of landfill gas from the landfill cover systems.
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Affiliation(s)
- Haijian Xie
- MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou, 310058, China
- Center for Balance Architecture, Zhejiang University, 148 Tianmushan Road, Hangzhou, 310007, China
| | - Xinru Zuo
- MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou, 310058, China
- Center for Balance Architecture, Zhejiang University, 148 Tianmushan Road, Hangzhou, 310007, China
| | - Yunmin Chen
- MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou, 310058, China
- Center for Balance Architecture, Zhejiang University, 148 Tianmushan Road, Hangzhou, 310007, China
| | - Huaxiang Yan
- MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou, 310058, China.
- Department of Mechanical, Aerospace and Civil Engineering, School of Engineering, The University of Manchester, Manchester, M13 9PL, UK.
| | - Junjun Ni
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, People's Republic of China
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Duan Z, Scheutz C, Kjeldsen P. Mitigation of methane emissions from three Danish landfills using different biocover systems. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 149:156-167. [PMID: 35738145 DOI: 10.1016/j.wasman.2022.05.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 05/02/2022] [Accepted: 05/26/2022] [Indexed: 06/15/2023]
Abstract
The establishment of biocover systems is an emerging methodology in reducing methane (CH4) emissions from landfills. This study investigated the performance of three biocover systems with different designs (biowindow and passively and actively loaded biofilters) in mitigating CH4 emissions from three landfills in Denmark. A series of field tests were carried out to evaluate the functionality of each system, and total CH4 emissions from relevant landfill sections or the entire landfill were measured before and after biocover implementation. Surface CH4 concentration screening and local CH4 fluxes showed generally low emissions from the biowindow/biofilters (mostly < 5 g CH4 m-2 d-1), although some hotspots were identified on two actively loaded biofilters. One passively loaded biofilter exhibited high CH4 emissions, mainly due to gas overloading into the system. Gas concentration profiles measured at different locations suggested uneven gas distribution in the biofilters, and significant CH4 oxidation occurred in both the gas distribution layer (when oxygen was fed into the system) and the CH4 oxidation layer. High CH4 oxidation efficiencies of above 95% were found in all systems except for one biofilter (55%). Whole-site emission measurements showed CH4 reduction efficiencies between 29 and 72% after implementing biocover systems at the three landfills, suggesting that they were efficient in reducing CH4 emissions. The most challenging task for the passively loaded biocover systems was to control gas flow and secure homogenous gas distribution, while for actively loaded biocovers, it might be more important to eliminate emission hotspots for better functionality.
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Affiliation(s)
- Zhenhan Duan
- Department of Environmental Engineering, Building 115, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Charlotte Scheutz
- Department of Environmental Engineering, Building 115, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Peter Kjeldsen
- Department of Environmental Engineering, Building 115, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
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Xie M, Guo X, Liu D. Leachate Pretreatment before Pipe Transportation: Reduction of Leachate Clogging Potential and Upgrading of Landfill Gas. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19106349. [PMID: 35627887 PMCID: PMC9140694 DOI: 10.3390/ijerph19106349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/19/2022] [Accepted: 05/20/2022] [Indexed: 01/27/2023]
Abstract
Leachate and landfill gas are the main contaminants produced by modern sanitary landfills. The leachate easily leads to clogging in the leachate transportation pipe, and the landfill gas can be used as renewable energy after the removal of CO2. The study aims to investigate the removal of the major scale forming ion of Ca2+ in leachate using raw landfill gas before pipe transportation. The research demonstrated that, under the given experimental conditions, the removal rate of Ca2+ in the leachate was positively correlated with the pH value of the leachate, and negatively correlated with the intake flow rate of the landfill gas; the highest removal rate of Ca2+ was achieved when the intake flow rate and volume were 0.05 L/min and 2.0 L, respectively, and the highest removal rate of Ca2+ from the leachate was about 90%. The maximum removal rate of CO2 from landfill gas could reach 95%, and the CO2 content of the post-reaction gas was as low as 1.74% (volume percentage). The scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis showed that the precipitate was spherical and mainly contained inorganic substances such as CaCO3, MgCO3, Ca(OH)2, Mg(OH)2, and SiO2. The study showed that, before the leachate was piped, the Ca2+ could be removed using the raw landfill gas, thereby reducing the potential for the formation of precipitation clogging in the pipeline. This study also provides new ideas for upgrading landfill gas to achieve a renewable-energy utilization plan, and reduces greenhouse gas emissions by reducing CO2 emissions from landfills.
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Affiliation(s)
- Mingde Xie
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 610031, China; (M.X.); (X.G.)
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China
| | - Xi Guo
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 610031, China; (M.X.); (X.G.)
| | - Dan Liu
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 610031, China; (M.X.); (X.G.)
- Correspondence:
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Zuo R, Han K, Xu D, Li Q, Liu J, Xue Z, Zhao X, Wang J. Response of environmental factors to attenuation of toluene in vadose zone. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 302:113968. [PMID: 34689029 DOI: 10.1016/j.jenvman.2021.113968] [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: 09/06/2021] [Revised: 10/08/2021] [Accepted: 10/17/2021] [Indexed: 06/13/2023]
Abstract
Contaminated groundwater migrates in reverse direction under capillary force in vadose zone, and the attenuation process of pollutant adsorption and microbial degradation changes the environment of vadose zone. In this study, the response of toluene to environmental factors during reverse migration and attenuation of toluene from aquifer to vadose zone was studied by column experiment and experimental data analysis. The changes of environmental factors, including potential of hydrogen (pH), dissolved oxygen (DO), and oxidation-reduction potential (ORP), and toluene concentration were monitored by soil column experiment under sterilized and non-sterilized conditions. The 16S rRNA molecular biological detection technology was used to quantitatively analyze the impact of microbial degradation on the environment. Finally, the correlation between environmental factors and concentration in the attenuation process of toluene in the vadose zone was quantitatively studied by Pearson Correlation Coefficient (PCC) and multivariate statistical equation. The results showed that pH was primarily affected by microbial degradation, and DO and ORP were primarily affected by both adsorption and microbial degradation. The attenuation of toluene was divided into two stages: adsorption dominated (0~26 d) and microbial degradation dominated (26~55 d). The degradation amounts of microorganisms at each position in the non-sterilized column from bottom to top were 9.37%, 55.34%, 68.64%, 75.70%, 66.03% and 42.50%. At the same time, the article proposes for the first time that there is an obvious functional relationship between environmental factors (DO, ORP, pH), time (t) and concentration (CToluene):CToluene=C0+A100t+Bα+Cβ+D100γ, (α,β,γ are the pH, DO and ORP of capillary water, respectively; A, B, C and D are all undetermined coefficients), R2 > 0.95. The results of this study may facilitate the use of simple and easy-to-obtain environmental factors to characterize the dynamic process of pollutant concentration changes.
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Affiliation(s)
- Rui Zuo
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing, 100875, China
| | - Kexue Han
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing, 100875, China
| | - Donghui Xu
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing, 100875, China.
| | - Qiao Li
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing, 100875, China
| | - Jiawei Liu
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing, 100875, China
| | - Zhenkun Xue
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing, 100875, China
| | - Xiao Zhao
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing, 100875, China
| | - Jinsheng Wang
- College of Water Sciences, Beijing Normal University, Beijing, 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education, Beijing, 100875, China
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Chu YX, Wang J, Tian G, He R. Reduction in VOC emissions by intermittent aeration in bioreactor landfills with gas-water joint regulation. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 290:118059. [PMID: 34488158 DOI: 10.1016/j.envpol.2021.118059] [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: 06/06/2021] [Revised: 08/17/2021] [Accepted: 08/25/2021] [Indexed: 06/13/2023]
Abstract
Landfill mining and reclamation is a new strategy for addressing the lack of space available for new landfills and realizing the sustainable development of landfills. A gas-water joint bioreactor landfill is regulated by injecting water and/or recirculating leachate, and a blasting aeration system to optimize waste stabilization. In this study, four landfill reactors were constructed to investigate the effects of ventilation methods, including continuous (20 h d-1) and intermittent aeration (4 h d-1 in continuous or 2-h aeration per 12 h, twice a day), on the degradation of organic matter and volatile organic compound (VOC) emissions in comparison with traditional landfills. A total of 62 VOCs were detected in the landfill reactors. Among them, halogenated compounds had the highest abundance (39.8-65.4 %), followed by oxygenated compounds, alkanes and alkenes, and aromatic compounds. Both intermittent and continuous aeration could accelerate the degradation of landfilled waste and increase the volatilization rate of VOCs. Compared with intermittent aeration, the degradation of landfilled waste was more quickly in the landfill reactor with continuous aeration. However, intermittent aeration could create anaerobic-anoxic-aerobic conditions, which were conducive to the growth and metabolism of anaerobic and aerobic microorganisms in landfills and thereby reduced more than 63.4 % of total VOC emissions from the landfill reactor with continuous aeration. Moreover, intermittent aeration could reduce the ventilation rate and decrease the cost of aeration by 80 % relative to continuous aeration. Firmicutes, Bacteroidetes, Proteobacteria and Tenericutes predominated in the landfill reactors. The environmental variables including organic matter and VOCs concentrations had significant influences on microbial community structure in the landfilled waste. These findings indicated that intermittent aeration was an effective way to accelerate the stabilization of landfilled waste and reduce the cost and environmental risks in bioreactor landfills with gas-water joint regulation.
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Affiliation(s)
- Yi-Xuan Chu
- Department of Environmental Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Jing Wang
- Department of Environmental Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Guangming Tian
- Department of Environmental Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Ruo He
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China; College of Environmental and Resource Science, Zhejiang University, Hangzhou, 310058, China.
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Kulig A, Szyłak-Szydłowski M, Wiśniewska M. Application of Chemical Sensors and Olfactometry Method in Ecological Audits of Degraded Areas. SENSORS 2021; 21:s21186190. [PMID: 34577395 PMCID: PMC8468849 DOI: 10.3390/s21186190] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/04/2021] [Accepted: 09/13/2021] [Indexed: 11/16/2022]
Abstract
Mineral excavation is a common process throughout the world. The open pits remaining after the closure of a mine require well-considered and meticulous reclamation activities aimed at restoring the environmental properties of a given area. The inspections carried out in Poland indicate numerous irregularities in implementing the reclamation process. The research in this study was conducted in six measurement series and includes both chemical and olfactometry determinations by devices: multisensor portable gas detector and field olfactometer. Statistical analysis of the results obtained show high concentrations in ambient air of both chemical compounds (NH3, VOCs, H2S, CH3SH) and odour, excluding the possibility of occurrence in the pit of only waste types contained in the administrative decision on reclamation. In addition to the unpleasant odour, the listed compounds can have dangerous effects on the health and life of living organisms. This paper presents a suitable method of control and detection of irregularities in the conducted processes. The main advantage is the relatively low cost of purchasing sensors and field olfactometers compared to other devices, and the possibility to test the polluted air in situ, without the risk of chemical processes occurring during transport of gas samples to the laboratory.
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Duan Z, Hansen POR, Scheutz C, Kjeldsen P. Mitigation of methane and trace gas emissions through a large-scale active biofilter system at Glatved landfill, Denmark. WASTE MANAGEMENT (NEW YORK, N.Y.) 2021; 126:367-376. [PMID: 33813314 DOI: 10.1016/j.wasman.2021.03.023] [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: 12/11/2020] [Revised: 03/08/2021] [Accepted: 03/15/2021] [Indexed: 06/12/2023]
Abstract
Biocover systems are a cost-effective technology utilised to mitigate methane (CH4) and trace gas emissions from landfills. A full-scale biofilter system was constructed at Glatved landfill, Denmark, consisting of three biofilters with a total area of 3950 m2. Landfill gas collected mainly from shredder waste cells was mixed with ambient air and fed actively into the biofilter, resulting in an average load of 60-75 g m-2 d-1 for CH4 and 0.15-0.21 g m-2 d-1 for trace gases (e.g., aromatics, chlorofluorocarbons (CFCs), aliphatic hydrocarbons). The initial CH4 surface screening showed uneven gas distribution into the system, and elevated surface concentrations were observed close to the gas inlet. Both positive and negative CH4 fluxes, ranging from -0.36 to 4.25 g m-2 d-1, were measured across the surface of the biofilter. Total trace gas emissions were between -0.005 and 0.042 g m-2 d-1, and the emission flux of individual compounds were generally small (10-8 to 10-3 g m-2 d-1). Vertical gas concentration profiles showed that the oxidation of CH4 and easily degradable trace compounds such as aromatics and aliphatic hydrocarbons happened in the aerobic zones, while CFCs were degraded in the anaerobic zone inside the compost layer. In addition, oxidation/degradation of CH4 and trace gases also occurred in the gas distribution layer, which contributed significantly to the overall mitigation efficiency of the biofilter system. Overall, the biofilter system showed mitigation efficiencies of nearly 100% for both CH4 and trace gases, and it might have the potential to work under higher loads.
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Affiliation(s)
- Zhenhan Duan
- Department of Environmental Engineering, Building 115, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
| | | | - Charlotte Scheutz
- Department of Environmental Engineering, Building 115, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Peter Kjeldsen
- Department of Environmental Engineering, Building 115, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
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