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Ferdowsi M, Khabiri B, Buelna G, Jones JP, Heitz M. Prolonged operation of a methane biofilter from acclimation to the failure stage. ENVIRONMENTAL TECHNOLOGY 2024; 45:2589-2598. [PMID: 36789628 DOI: 10.1080/09593330.2023.2179421] [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: 04/13/2022] [Accepted: 02/05/2023] [Indexed: 06/18/2023]
Abstract
Global warming needs immediate attention to reduce major greenhouse gas emissions such as methane (CH4). Bio-oxidation of dilute CH4 emissions in packed-bed bioreactors such as biofilters has been carried out over recent years at laboratory and large scales. However, a big challenge is to keep CH4 biofilters running for a long period. In this study, a packed-bed lab-scale bioreactor with a specialized inorganic-based filter bed was successfully operated over four years for CH4 elimination. The inoculation of the bioreactor was the active leachate of another CH4 biofilter which resulted in a fast acclimation and removal efficiency (RE) reached 80% after seven weeks of operation for CH4 inlet concentrations ranging from 700 to 800 ppmv and an empty bed residence time (EBRT) of 6 min. During four years of operation, the bioreactor often recorded REs higher than 65% for inlet concentrations in the range of 1900-2200 ppmv and an EBRT of 6 min. The rate and interval of the nutrient supply played an important role in maintaining the bioreactor's high performance over the long operation. Forced shutdowns were unavoidable during the 4-year operation and the bioreactor fully tolerated them with a partial recovery within one week and a progressive recovery over time. In the end, the bioreactor's filter bed started to deteriorate due to a long shutdown of twelve weeks and the extended operation of four years when the RE dropped to below 8% with no sign of returning to its earlier performance.
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Affiliation(s)
- Milad Ferdowsi
- Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Bahman Khabiri
- Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Gerardo Buelna
- Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - J Peter Jones
- Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Michèle Heitz
- Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, Sherbrooke, Québec, Canada
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2
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Huang D, Du Y, Xu Q, Ko JH. Quantification and control of gaseous emissions from solid waste landfill surfaces. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 302:114001. [PMID: 34731706 DOI: 10.1016/j.jenvman.2021.114001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 10/18/2021] [Accepted: 10/23/2021] [Indexed: 06/13/2023]
Abstract
Landfilling is the most common option for solid waste disposal worldwide. Landfill sites can emit significant quantities of greenhouse gases (GHGs; e.g., methane, carbon dioxide, and nitrous oxide) and release toxic and odorous compounds (e.g., sulfides). Due to the complex composition and characteristics of landfill surface gas emissions, the quantification and control of landfill emissions are challenging. This review attempts to comprehensively understand landfill emission quantification and control options by primarily focusing on GHGs and odor compounds. Landfill emission quantification was highlighted by combining different emissions monitoring approaches to improve the quality of landfill emission data. Also, landfill emission control requires a specific approach that targets emission compounds or a systematic approach that reduces overall emissions by combining different control methods since the diverse factors dominate the emissions of various compounds and their transformation. This integrated knowledge of emission quantification and control options for GHGs and odor compounds is beneficial for establishing field monitoring campaigns and incorporating mitigation strategies to quantify and control multiple landfill emissions.
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Affiliation(s)
- Dandan Huang
- Key Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, Guangdong, 518055, China; School of Ecology, Sun Yat-sen University, Shenzhen, 518107, China
| | - Yue Du
- Key Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, Guangdong, 518055, China
| | - Qiyong Xu
- Key Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, Guangdong, 518055, China
| | - Jae Hac Ko
- Department of Environmental Engineering, College of Ocean Sciences, Jeju National University, Jeju Special Self-Governing Province, 63243, Republic of Korea.
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Khabiri B, Ferdowsi M, Buelna G, Jones JP, Heitz M. Bioelimination of low methane concentrations emitted from wastewater treatment plants: a review. Crit Rev Biotechnol 2021; 42:450-467. [PMID: 34261394 DOI: 10.1080/07388551.2021.1940830] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Sewage from residents and industries is collected and transported to wastewater treatment plants (WWTPs) with sewer networks. The operation of WWTPs results in emissions of greenhouse gases, such as methane (CH4), mostly due to sludge anaerobic digestion. Amounts of emissions depend on the source of influent, i.e. municipal and industrial wastewater as well as sewer systems (gravity and rising). Wastewater is the fifth-largest source of anthropogenic CH4 emissions in the world and represents 7-9% of total global CH4 emissions into the atmosphere. Global wastewater CH4 emission grew by approximately 20% from 2005 to 2020 and is expected to grow by 8% between 2020 and 2030, which makes wastewater an important CH4 emitter worldwide. This review initially considers the emission of CH4 from WWTPs and sewer networks. In the second part, biotechniques available for biodegradation of low CH4 concentrations (<5% v/v) encountered in WWTPs have been studied. The paper reviews major bioreactor configurations for the treatment of polluted air, i.e. biotrickling filters, bioscrubbers, two-liquid phase bioreactors, biofilters, and hybrid reactor configurations, after which it focuses on CH4 biofiltration systems. Biofiltration represents a simple and efficient approach to bio-oxidize CH4 in waste gases from WWTPs. Major factors influencing a biofilter's performance along with knowledge gaps in relation to its application for treating gaseous emissions from WWTPs are discussed.
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Affiliation(s)
- Bahman Khabiri
- Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, Sherbrooke, Canada
| | - Milad Ferdowsi
- Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, Sherbrooke, Canada
| | - Gerardo Buelna
- Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, Sherbrooke, Canada
| | - J Peter Jones
- Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, Sherbrooke, Canada
| | - Michèle Heitz
- Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, Sherbrooke, Canada
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Huang D, Yang L, Ko JH, Xu Q. Comparison of the methane-oxidizing capacity of landfill cover soil amended with biochar produced using different pyrolysis temperatures. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 693:133594. [PMID: 31377353 DOI: 10.1016/j.scitotenv.2019.133594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 07/08/2019] [Accepted: 07/24/2019] [Indexed: 06/10/2023]
Abstract
The in-situ mitigation of methane (CH4) in landfill gas using landfill cover soil (LCS) is a cost-effective approach, but its efficiency needs to be enhanced. In this study, we incorporated an enriched methane-oxidizing bacteria (MOB) consortium into LCS and established four biochar-amended LCS groups with biochar produced at 300 °C (BC300), 400 °C (BC400), 500 °C (BC500), and 600 °C (BC600). The purpose was to evaluate the CH4 oxidation capacity of biochar-amended LCS after inoculation with MOB and to investigate how the physicochemical properties of biochar that are influenced by the pyrolysis temperature affect the performance and microbial activity of biochar-amended LCS. It was found that a 15% volume ratio (representing a mass ratio of 2.49%-2.78%) for biochar amendment in LCS enhanced CH4 removal efficiency, with the highest removal observed to be 46% for BC400-amended LCS compared to 30% for the original LCS. In addition, CH4 adsorption by the biochar was not observed, and a 15% mass ratio for biochar in the LCS had no or a negative impact. Besides improving the water-holding capacity and gas permeability of LCS, other possible advantages of biochar amendment in terms of CH4 oxidization include greater retention of nutrients, electron acceptors, and exchangeable cations, as well as introducing iron ions. It was also found that CH4 oxidation capacity and the methanotroph activity of biochar-amended LCS did not continue to increase with higher pyrolysis temperatures, even though higher micropore volumes and surface areas were obtained at higher pyrolysis temperatures. From this study, BC400 was identified as the optimal choice for the best performance in terms of enhancing both the CH4 oxidation capacity of the amended LCS and the growth of type II methanotroph Methylocystaceae, which can possibly be attributed to having the highest cation exchange capacity of the four biochars.
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Affiliation(s)
- Dandan Huang
- Shenzhen Engineering Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, University Town, Xili, Nanshan District, Shenzhen 518055, PR China
| | - Luning Yang
- Shenzhen Engineering Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, University Town, Xili, Nanshan District, Shenzhen 518055, PR China
| | - Jae Hac Ko
- Shenzhen Engineering Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, University Town, Xili, Nanshan District, Shenzhen 518055, PR China
| | - Qiyong Xu
- Shenzhen Engineering Laboratory for Eco-efficient Recycled Materials, School of Environment and Energy, Peking University Shenzhen Graduate School, University Town, Xili, Nanshan District, Shenzhen 518055, PR China.
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Liu F, Fiencke C, Guo J, Lyu T, Dong R, Pfeiffer EM. Optimisation of bioscrubber systems to simultaneously remove methane and purify wastewater from intensive pig farms. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:15847-15856. [PMID: 30955200 DOI: 10.1007/s11356-019-04924-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 03/20/2019] [Indexed: 06/09/2023]
Abstract
The use of bioscrubber is attracting increasing attention for exhaust gas treatment in intensive pig farming. However, the challenge is to improve the methane (CH4) removal efficiency as well as the possibility of pig house wastewater treatment. Three laboratory-scale bioscrubbers, each equipped with different recirculation water types, livestock wastewater (10-times-diluted pig house wastewater supernatant), a methanotroph growth medium (10-times-diluted), and tap water, were established to evaluate the performance of CH4 removal and wastewater treatment. The results showed that enhanced CH4 removal efficiency (25%) can be rapidly achieved with improved methanotrophic activity due to extra nutrient support from the wastewater. The majority of the CH4 was removed in the middle to end part of the bioscrubbers, which indicated that CH4 removal could be potentially optimised by extending the length of the reactor. Moreover, 52-86% of the ammonium (NH4+-N), total organic carbon (TOC), and phosphate (PO43--P) removal were simultaneously achieved with CH4 removal in the present study. Based on these results, this study introduces a low-cost and simple-to-operate method to improve CH4 removal and simultaneously treat pig farm wastewater in bioscrubbers.
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Affiliation(s)
- Fang Liu
- College of Engineering, China Agricultural University (Key Laboratory for Clean Renewable Energy Utilization Technology, Ministry of Agriculture), Qinghua East Road 17, Beijing, 100083, China
- Center for Earth System Research and Sustainability, Institute of Soil Science, Universität Hamburg, Allende-Platz 2, 20146, Hamburg, Germany
| | - Claudia Fiencke
- Center for Earth System Research and Sustainability, Institute of Soil Science, Universität Hamburg, Allende-Platz 2, 20146, Hamburg, Germany
| | - Jianbin Guo
- College of Engineering, China Agricultural University (Key Laboratory for Clean Renewable Energy Utilization Technology, Ministry of Agriculture), Qinghua East Road 17, Beijing, 100083, China.
| | - Tao Lyu
- School of Animal Rural & Environmental Sciences, Nottingham Trent University, Nottinghamshire, NG25 0QF, UK.
| | - Renjie Dong
- College of Engineering, China Agricultural University (Key Laboratory for Clean Renewable Energy Utilization Technology, Ministry of Agriculture), Qinghua East Road 17, Beijing, 100083, China
| | - Eva-Maria Pfeiffer
- Center for Earth System Research and Sustainability, Institute of Soil Science, Universität Hamburg, Allende-Platz 2, 20146, Hamburg, Germany
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López JC, Porca E, Collins G, Clifford E, Quijano G, Muñoz R. Ammonium influences kinetics and structure of methanotrophic consortia. WASTE MANAGEMENT (NEW YORK, N.Y.) 2019; 89:345-353. [PMID: 31079748 DOI: 10.1016/j.wasman.2019.04.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Revised: 04/02/2019] [Accepted: 04/12/2019] [Indexed: 06/09/2023]
Abstract
The literature is conflicted on the influence of ammonium on the kinetics and microbial ecology of methanotrophy. In this study, methanotrophic cultures were enriched, under ammonium concentrations ranging from 0 to 200 mM, from an inoculum comprising leachate and top-cover soil from a landfill. Specific CH4 biodegradation rates were highest (7.8 × 10-4 ± 6.0 × 10-5 gCH4 gX-1 h-1) in cultures enriched at 4 mM NH4+, which were mainly dominated by type II methanotrophs belonging to Methylocystis spp. Lower specific CH4 oxidation rates (average values of 1.8-3.6 × 10-4 gCH4 gX-1 h-1) were achieved by cultures enriched at higher NH4+ concentrations (20 and 80 mM), and had higher affinity for CH4 compared to 4 mM enrichments. These lower affinities were attributed to lower diversity dominated by type I methanotrophs, of the Methylosarcina, Methylobacter and Methylomicrobium genera, encountered with increasing concentrations of NH4+. The study indicates that CH4 oxidation biotechnologies applied at low NH4+ concentrations can support efficient abatement of CH4 and high diversity of methanotrophic consortia, whilst enriching type II methanotrophs.
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Affiliation(s)
- Juan C López
- Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain
| | - Estefanía Porca
- Microbial Communities Laboratory, School of Natural Sciences, National University of Ireland Galway, University Road, Galway H91 TK33, Ireland; Ryan Institute, National University of Ireland Galway, University Road, Galway H91 TK33, Ireland
| | - Gavin Collins
- Microbial Communities Laboratory, School of Natural Sciences, National University of Ireland Galway, University Road, Galway H91 TK33, Ireland; Ryan Institute, National University of Ireland Galway, University Road, Galway H91 TK33, Ireland
| | - Eoghan Clifford
- Ryan Institute, National University of Ireland Galway, University Road, Galway H91 TK33, Ireland; College of Engineering and Informatics, National University of Ireland Galway, University Road, Galway H91 F677, Ireland
| | - Guillermo Quijano
- Laboratory for Research on Advanced Processes for Water Treatment, Instituto de Ingeniería, Unidad Académica Juriquilla, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, Querétaro 76230, Mexico
| | - Raúl Muñoz
- Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain; Institute of Sustainable Proceses, University of Valladolid, Spain.
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7
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Liu F, Wienke C, Fiencke C, Guo J, Dong R, Pfeiffer EM. Biofilter with mixture of pine bark and expanded clay as packing material for methane treatment in lab-scale experiment and field-scale implementation. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:31297-31306. [PMID: 30194576 DOI: 10.1007/s11356-018-3102-z] [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: 06/08/2018] [Accepted: 08/28/2018] [Indexed: 06/08/2023]
Abstract
Low methane (CH4) emission reduction efficiency (< 25%) has been prevalent due to inefficient biological exhaust gas treatment facilities in mechanic biological waste treatment plants (MBTs) in Germany. This study aimed to quantify the improved capacity of biofilters composed of a mixture of organic (pine bark) and inorganic (expanded clay) packing materials in reducing CH4 emissions in both a lab-scale experiment and field-scale implementation. CH4 removal performance was evaluated using lab-scale biofilter columns under varied inflow CH4 concentrations (70, 130, and 200 g m-3) and corresponding loading rates of 8.2, 4.76, and 3.81 g m-3 h-1, respectively. The laboratory CH4 removal rates (1.2-2.2 g m-3 h-1) showed positive correlation with the inflow CH4 loading rates (4-8.2 g m-3 h-1), indicating high potential for field-scale implementation. Three field-scale biofilter systems with the proposed mixture packing materials were constructed in an MBT in Neumünster, northern Germany. A relatively stable CH4 removal efficiency of 38-50% was observed under varied inflow CH4 concentrations of 28-39 g m-3 (loading rates of 1120-2340 g m-3 h-1) over a 24-h period. The CH4 removal rate was approximately 500-700 g m-3 h-1, which was significantly higher than relevant previously reported field-scale biofilter systems (16-50 g m-3 h-1). The present study provides a promising configuration of biofilter systems composed of a mixture of organic (pine bark) and inorganic (expanded clay) packing materials to achieve high CH4 emission reduction. Graphic abstract ᅟ.
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Affiliation(s)
- Fang Liu
- College of Engineering (Key Laboratory for Clean Renewable Energy Utilization Technology, Ministry of Agriculture), China Agricultural University, Qinghua East Road 17, Beijing, 100083, China
- Center for Earth System Research and Sustainability, Institute of Soil Science, Universität Hamburg, Allende-Platz 2, 20146, Hamburg, Germany
| | - Cindy Wienke
- Center for Earth System Research and Sustainability, Institute of Soil Science, Universität Hamburg, Allende-Platz 2, 20146, Hamburg, Germany
| | - Claudia Fiencke
- Center for Earth System Research and Sustainability, Institute of Soil Science, Universität Hamburg, Allende-Platz 2, 20146, Hamburg, Germany
| | - Jianbin Guo
- College of Engineering (Key Laboratory for Clean Renewable Energy Utilization Technology, Ministry of Agriculture), China Agricultural University, Qinghua East Road 17, Beijing, 100083, China.
| | - Renjie Dong
- College of Engineering (Key Laboratory for Clean Renewable Energy Utilization Technology, Ministry of Agriculture), China Agricultural University, Qinghua East Road 17, Beijing, 100083, China
| | - Eva-Maria Pfeiffer
- Center for Earth System Research and Sustainability, Institute of Soil Science, Universität Hamburg, Allende-Platz 2, 20146, Hamburg, Germany
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Fedrizzi F, Cabana H, Ndanga ÉM, Cabral AR. Biofiltration of methane from cow barns: Effects of climatic conditions and packing bed media acclimatization. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 78:669-676. [PMID: 32559958 DOI: 10.1016/j.wasman.2018.06.038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 06/17/2018] [Accepted: 06/18/2018] [Indexed: 06/11/2023]
Abstract
The performance of biofiltration to mitigate CH4 emissions from cow barns was investigated in the laboratory using two flow-through columns constructed with an acclimatized packed bed media composed of inexpensive materials and readily available in an agricultural context. The biofilters were fed with artificial exhaust gas at a constant rate of 0.036 m3 h-1 and low inlet CH4 concentration (0.22 g m-3 = 300 ppm). The empty-bed residence time (EBRT) was equal to 0.21 h. Additionally, in order to simulate temperature changes under natural conditions and determine the influence of such cycles on CH4 removal efficiency, the upper part of the biofilters were submitted to temperature oscillations over time. The maximum oxidation rate (1.68 μg CH4 gdw-1h-1) was obtained with the commercial compost mixed with straw. Accordingly, it was considered as packing bed media for the biofilters. The CH4 removal efficiency was affected by the temperature prevailing within the biofilters, by the way in which the cooling-warming cycles were applied and by the acclimatization process. The shorter the cooling-warming cycles, the more oxidation rates varied. With longer cycles, CH4 removal rates stabilized and CH4 removal efficiencies attained nearly 100% in both biofilters, and remained at this level for more than 100 days, irrespective of the temperature at the top of the biofilter, which was - at times - adverse for microbiological activity. The first order rate constant for CH4 oxidation kinetics of the entire system was estimated at 15 h-1. If such rate could be transposed to real field conditions in Canada, home to nearly 945,000 dairy cows, biofiltration may be applied to efficiently abate between 2 × 106 and 3 × 106 t yr-1 of CO2 equivalent (depending on how estimates are performed) from bovine enteric fermentation alone.
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Affiliation(s)
| | - Hubert Cabana
- Environmental Engineering Laboratory, Department of Civil Engineering, Université de Sherbrooke, Sherbrooke J1K 2R1, Canada.
| | - Éliane M Ndanga
- Akvo, 6440, 13e Avenue, Montréal, Québec H1X 2Y7, Canada(1).
| | - Alexandre R Cabral
- Geoenvironmental Group, Department of Civil Engineering, University of Sherbrooke, Sherbrooke, Quebec J1K 2R1, Canada.
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Ferdowsi M, Ramirez AA, Jones JP, Heitz M. Methane biofiltration in the presence of ethanol vapor under steady and transient state conditions: an experimental study. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:20883-20896. [PMID: 28721620 DOI: 10.1007/s11356-017-9634-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 06/26/2017] [Indexed: 06/07/2023]
Abstract
Methane (CH4) removal in the presence of ethanol vapors was performed by a stone-based bed and a hybrid packing biofilter in parallel. In the absence of ethanol, a methane removal efficiency of 55 ± 1% was obtained for both biofilters under similar CH4 inlet load (IL) of 13 ± 0.5 gCH4 m-3 h-1 and an empty bed residence time (EBRT) of 6 min. The results proved the key role of the bottom section in both biofilters for simultaneous removal of CH4 and ethanol. Ethanol vapor was completely eliminated in the bottom sections for an ethanol IL variation between 1 and 11 gethanol m-3 h-1. Ethanol absorption and accumulation in the biofilm phase as well as ethanol conversion to CO2 contributed to ethanol removal efficiency of 100%. In the presence of ethanol vapor, CO2 productions in the bottom section increased almost fourfold in both biofilters. The ethanol concentration in the leachate of the biofilter exceeding 2200 gethanol m-3leachate in both biofilters demonstrated the excess accumulation of ethanol in the biofilm phase. The biofilters responded quickly to an ethanol shock load followed by a starvation with 20% decrease of their performance. The return to normal operations in both biofilters after the transient conditions took less than 5 days. Unlike the hybrid packing biofilter, excess pressure drop (up to 1.9 cmH2O m-1) was an important concern for the stone bed biofilter. The biomass accumulation in the bottom section of the stone bed biofilter contributed to 80% of the total pressure drop. However, the 14-day starvation reduced the pressure drop to 0.25 cmH2O m-1.
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Affiliation(s)
- Milad Ferdowsi
- Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, Sherbrooke, QC, J1K 2R1, Canada
| | - Antonio Avalos Ramirez
- Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, Sherbrooke, QC, J1K 2R1, Canada
- Centre National en Électrochimie et en Technologies Environnementales, 2263, Avenue du Collège, Shawinigan, QC, G9N 6V8, Canada
| | - Joseph Peter Jones
- Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, Sherbrooke, QC, J1K 2R1, Canada
| | - Michèle Heitz
- Department of Chemical Engineering and Biotechnological Engineering, Faculty of Engineering, Université de Sherbrooke, Sherbrooke, QC, J1K 2R1, Canada.
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