1
|
Huang D, Chen Y, Bai X, Zhang R, Chen Q, Wang N, Xu Q. Methane removal efficiencies of biochar-mediated landfill soil cover with reduced depth. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 355:120487. [PMID: 38422848 DOI: 10.1016/j.jenvman.2024.120487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 02/15/2024] [Accepted: 02/21/2024] [Indexed: 03/02/2024]
Abstract
Biochar amendment for landfill soil cover has the potential to enhance methane removal efficiency while minimizing the soil depth. However, there is a lack of information on the response of biochar-mediated soil cover to the changes in configuration and operational parameters during the methane transport and transformation processes. This study constructed three biochar-amended landfill soil covers, with reduced soil depths from 75 cm (C2) to 55 cm (C3) and 45 cm (C4), and the control group (C1) with 75 cm and no biochar. Two operation phases were conducted under two soil moisture contents and three inlet methane fluxes in each phase. The methane removal efficiency increased for all columns along with the increase in methane flux. However, increasing moisture content from 10% to 20% negatively influenced the methane removal efficiency due to mass transfer limitation when at a low inlet methane flux, especially for C1; while this adverse effect could be alleviated by a high flux. Except for the condition with low moisture content and flux combination, C3 showed comparable methane removal efficiency to C2, both dominating over C1. As for C4 with only 45 cm, a high moisture content combined with a high methane flux enabled its methane removal efficiency to be competitive with other soil depths. In addition to the geotechnical reasons for gas transport processes, the evolution in methanotroph community structure (mainly type I methanotrophs) induced by biochar amendment and variations in soil properties supplemented the biological reasons for the varying methane removal efficiencies.
Collapse
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, China; School of Ecology, Sun Yat-sen University, No. 66, Gongchang Road, Guangming District, Shenzhen, 0020518107, China
| | - Yuke Chen
- 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, China
| | - Xinyue Bai
- 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, China
| | - Rujie Zhang
- 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, China
| | - Qindong Chen
- 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, China
| | - Ning Wang
- 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, 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, China.
| |
Collapse
|
2
|
Ray S, Jin JO, Choi I, Kim M. Recent trends of biotechnological production of polyhydroxyalkanoates from C1 carbon sources. Front Bioeng Biotechnol 2023; 10:907500. [PMID: 36686222 PMCID: PMC9852868 DOI: 10.3389/fbioe.2022.907500] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 12/06/2022] [Indexed: 01/09/2023] Open
Abstract
Growing concerns over the use of limited fossil fuels and their negative impacts on the ecological niches have facilitated the exploration of alternative routes. The use of conventional plastic material also negatively impacts the environment. One such green alternative is polyhydroxyalkanoates, which are biodegradable, biocompatible, and environmentally friendly. Recently, researchers have focused on the utilization of waste gases particularly those belonging to C1 sources derived directly from industries and anthropogenic activities, such as carbon dioxide, methane, and methanol as the substrate for polyhydroxyalkanoates production. Consequently, several microorganisms have been exploited to utilize waste gases for their growth and biopolymer accumulation. Methylotrophs such as Methylobacterium organophilum produced highest amount of PHA up to 88% using CH4 as the sole carbon source and 52-56% with CH3OH. On the other hand Cupriavidus necator, produced 71-81% of PHA by utilizing CO and CO2 as a substrate. The present review shows the potential of waste gas valorization as a promising solution for the sustainable production of polyhydroxyalkanoates. Key bottlenecks towards the usage of gaseous substrates obstructing their realization on a large scale and the possible technological solutions were also highlighted. Several strategies for PHA production using C1 gases through fermentation and metabolic engineering approaches are discussed. Microbes such as autotrophs, acetogens, and methanotrophs can produce PHA from CO2, CO, and CH4. Therefore, this article presents a vision of C1 gas into bioplastics are prospective strategies with promising potential application, and aspects related to the sustainability of the system.
Collapse
Affiliation(s)
- Subhasree Ray
- Research Institute of Cell Culture, Yeungnam University, Gyeongsan, South Korea,Department of Life Science, School of Basic Science and Research, Sharda University, Greater Noida, India,*Correspondence: Myunghee Kim, ; Subhasree Ray,
| | - Jun-O Jin
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, South Korea,Department of Food Science and Technology, Yeungnam University, Gyeongsan, South Korea
| | - Inho Choi
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, South Korea,Department of Food Science and Technology, Yeungnam University, Gyeongsan, South Korea
| | - Myunghee Kim
- Research Institute of Cell Culture, Yeungnam University, Gyeongsan, South Korea,Department of Food Science and Technology, Yeungnam University, Gyeongsan, South Korea,*Correspondence: Myunghee Kim, ; Subhasree Ray,
| |
Collapse
|
3
|
Cattaneo CR, Rodríguez Y, Rene ER, García-Depraect O, Muñoz R. Biogas bioconversion into poly(3-hydroxybutyrate) by a mixed microbial culture in a novel Taylor flow bioreactor. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 150:364-372. [PMID: 35914413 DOI: 10.1016/j.wasman.2022.07.017] [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: 04/05/2022] [Revised: 07/07/2022] [Accepted: 07/16/2022] [Indexed: 06/15/2023]
Abstract
Biogas-based biopolymer production represents an alternative biogas valorization route with potential to cut down plastic pollution and greenhouse gas emissions. This study investigated for the first time the continuous bioconversion of methane, contained in biogas, into poly(3-hydroxybutyrate) (PHB) by a mixed methanotrophic culture using an innovative high mass-transfer Taylor flow bioreactor. Following a hydrodynamic flow regime mapping, the influence of the gas residence time and the internal gas recirculation on CH4 abatement was assessed under non nutrient limiting conditions. Under optimal operational conditions (gas residence time of 60 min and internal gas recycling ratio of 17), the bioreactor was able to support a CH4 removal efficiency of 63.3%, a robust CH4 elimination capacity (17.2 g-CH4 m-3h-1) and a stable biomass concentration (1.0 g L-1). The simultaneous CH4 abatement and PHB synthesis was investigated under 24-h:24-h nitrogen feast/famine continuous operation. The cyclic nitrogen starvation and the Taylor flow imposed in the bioreactor resulted in a relatively constant biomass concentration of 0.6 g L-1 with PHB contents ranging from 11 to 32% w w-1 (on a dry weight basis), entailing an average PHB productivity of 5.9 g-PHB m-3 d-1 with an associated PHB yield of 19.8 mg-PHB g-CH4-1. Finally, the molecular analysis of the microbial population structure indicated that type II methanotrophs outcompeted non-PHB accumulating type I methanotrophs, with a heterotrophic-methanotrophic consortium enriched in Methylocystis, Hyphomicrobium, Rubinisphaeraceae SH PL14 and Pseudonocardia.
Collapse
Affiliation(s)
- Carlos R Cattaneo
- Institute of Sustainable Processes, Dr. Mergelina s/n, 47011 Valladolid, Spain; Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid, Spain; Department of Water Supply, Sanitation and Environmental Engineering, IHE Delft Institute for Water Education, Westvest 7, 2611AX Delft, the Netherlands
| | - Yadira Rodríguez
- Institute of Sustainable Processes, Dr. Mergelina s/n, 47011 Valladolid, Spain; Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid, Spain
| | - Eldon R Rene
- Department of Water Supply, Sanitation and Environmental Engineering, IHE Delft Institute for Water Education, Westvest 7, 2611AX Delft, the Netherlands
| | - Octavio García-Depraect
- Institute of Sustainable Processes, Dr. Mergelina s/n, 47011 Valladolid, Spain; Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid, Spain
| | - Raúl Muñoz
- Institute of Sustainable Processes, Dr. Mergelina s/n, 47011 Valladolid, Spain; Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina s/n, 47011 Valladolid, Spain.
| |
Collapse
|
4
|
Integrative Genome-Scale Metabolic Modeling Reveals Versatile Metabolic Strategies for Methane Utilization in Methylomicrobium album BG8. mSystems 2022; 7:e0007322. [PMID: 35258342 PMCID: PMC9040813 DOI: 10.1128/msystems.00073-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Methylomicrobium album BG8 is an aerobic methanotrophic bacterium with promising features as a microbial cell factory for the conversion of methane to value-added chemicals. However, the lack of a genome-scale metabolic model (GEM) of M. album BG8 has hindered the development of systems biology and metabolic engineering of this methanotroph. To fill this gap, a high-quality GEM was constructed to facilitate a system-level understanding of the biochemistry of M. album BG8. Flux balance analysis, constrained with time-series data derived from experiments with various levels of methane, oxygen, and biomass, was used to investigate the metabolic states that promote the production of biomass and the excretion of carbon dioxide, formate, and acetate. The experimental and modeling results indicated that M. album BG8 requires a ratio of ∼1.5:1 between the oxygen- and methane-specific uptake rates for optimal growth. Integrative modeling revealed that at ratios of >2:1 oxygen-to-methane uptake flux, carbon dioxide and formate were the preferred excreted compounds, while at ratios of <1.5:1 acetate accounted for a larger fraction of the total excreted flux. Our results showed a coupling between biomass production and the excretion of carbon dioxide that was linked to the ratio between the oxygen- and methane-specific uptake rates. In contrast, acetate excretion was experimentally detected during exponential growth only when the initial biomass concentration was increased. A relatively lower growth rate was also observed when acetate was produced in the exponential phase, suggesting a trade-off between biomass and acetate production. IMPORTANCE A genome-scale metabolic model (GEM) is an integrative platform that enables the incorporation of a wide range of experimental data. It is used to reveal system-level metabolism and, thus, clarify the link between the genotype and phenotype. The lack of a GEM for Methylomicrobium album BG8, an aerobic methane-oxidizing bacterium, has hindered its use in environmental and industrial biotechnology applications. The diverse metabolic states indicated by the GEM developed in this study demonstrate the versatility in the methane metabolic processes used by this strain. The integrative GEM presented here will aid the implementation of the design-build-test-learn paradigm in the metabolic engineering of M. album BG8. This advance will facilitate the development of a robust methane bioconversion platform and help to mitigate methane emissions from environmental systems.
Collapse
|
5
|
Kulkarni PP, Chavan SB, Deshpande MS, Sagotra D, Kumbhar PS, Ghosalkar AR. Enrichment of Methylocystis dominant mixed culture from rice field for PHB production. J Biotechnol 2022; 343:62-70. [PMID: 34838616 DOI: 10.1016/j.jbiotec.2021.11.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/16/2021] [Accepted: 11/20/2021] [Indexed: 11/16/2022]
Abstract
Presence of methanotrophs in diverse environmental habitats helps to reduce emissions of greenhouse gas like methane. Isolation and culture of undiscovered wealth of methanotrophic organisms can help in exploitation of these organisms in value added products. The present study focuses on the enrichment of methanotroph dominated mixed microbial community by use of three stage strategy of revival, proliferation, and segregation. During the enrichment process amplicon sequencing of 16 s rRNA V3-V4 region showed relative abundance of mixed culture comprising single methanotrophic species of Methylocystis genus (88.92%) along with only three other species. Methylocystis dominant mixed culture (MMI-11) was observed to produce polyhydroxyalkanoates (PHA). During studies to identify favourable culture conditions, nitrate was found to be preferred nitrogen source for growth and PHA production. Cell growth ability to produce PHA was also evaluated at 14 L fermentor by supplying gas using continuous bubbling and through pressurization in the headspace. The mixed methanotrophic culture was found to accumulate maximum of 22.20% polyhydroxybutyrate (PHB) under nitrate limited condition. The molecular weight of PHB was found to be 2.221 × 105 g mol-1 with polydispersity of 1.82.
Collapse
Affiliation(s)
- Pranav P Kulkarni
- Department of Technology, Savitribai Phule Pune University, Pune, India; Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India
| | - Sambhaji B Chavan
- Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India
| | - Mandar S Deshpande
- Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India
| | - Dhanishta Sagotra
- Department of Technology, Savitribai Phule Pune University, Pune, India
| | - Pramod S Kumbhar
- Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India
| | - Anand R Ghosalkar
- Department of Technology, Savitribai Phule Pune University, Pune, India; Praj Matrix - R&D Centre, division of Praj Industries Limited, Urawade, Pune, India.
| |
Collapse
|
6
|
Gęsicka A, Oleskowicz-Popiel P, Łężyk M. Recent trends in methane to bioproduct conversion by methanotrophs. Biotechnol Adv 2021; 53:107861. [PMID: 34710553 DOI: 10.1016/j.biotechadv.2021.107861] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 10/11/2021] [Accepted: 10/20/2021] [Indexed: 12/26/2022]
Abstract
Methane is an abundant and low-cost gas with high global warming potential and its use as a feedstock can help mitigate climate change. Variety of valuable products can be produced from methane by methanotrophs in gas fermentation processes. By using methane as a sole carbon source, methanotrophic bacteria can produce bioplastics, biofuels, feed additives, ectoine and variety of other high-value chemical compounds. A lot of studies have been conducted through the years for natural methanotrophs and engineered strains as well as methanotrophic consortia. These have focused on increasing yields of native products as well as proof of concept for the synthesis of new range of chemicals by metabolic engineering. This review shows trends in the research on key methanotrophic bioproducts since 2015. Despite certain limitations of the known production strategies that makes commercialization of methane-based products challenging, there is currently much attention placed on the promising further development.
Collapse
Affiliation(s)
- Aleksandra Gęsicka
- Water Supply and Bioeconomy Division, Faculty of Environmental Engineering and Energy, Poznan University of Technology, Berdychowo 4, 60-965 Poznan, Poland
| | - Piotr Oleskowicz-Popiel
- Water Supply and Bioeconomy Division, Faculty of Environmental Engineering and Energy, Poznan University of Technology, Berdychowo 4, 60-965 Poznan, Poland.
| | - Mateusz Łężyk
- Water Supply and Bioeconomy Division, Faculty of Environmental Engineering and Energy, Poznan University of Technology, Berdychowo 4, 60-965 Poznan, Poland.
| |
Collapse
|
7
|
Karthikeyan OP, Smith TJ, Dandare SU, Parwin KS, Singh H, Loh HX, Cunningham MR, Williams PN, Nichol T, Subramanian A, Ramasamy K, Kumaresan D. Metal(loid) speciation and transformation by aerobic methanotrophs. MICROBIOME 2021; 9:156. [PMID: 34229757 PMCID: PMC8262016 DOI: 10.1186/s40168-021-01112-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 06/09/2021] [Indexed: 05/06/2023]
Abstract
Manufacturing and resource industries are the key drivers for economic growth with a huge environmental cost (e.g. discharge of industrial effluents and post-mining substrates). Pollutants from waste streams, either organic or inorganic (e.g. heavy metals), are prone to interact with their physical environment that not only affects the ecosystem health but also the livelihood of local communities. Unlike organic pollutants, heavy metals or trace metals (e.g. chromium, mercury) are non-biodegradable, bioaccumulate through food-web interactions and are likely to have a long-term impact on ecosystem health. Microorganisms provide varied ecosystem services including climate regulation, purification of groundwater, rehabilitation of contaminated sites by detoxifying pollutants. Recent studies have highlighted the potential of methanotrophs, a group of bacteria that can use methane as a sole carbon and energy source, to transform toxic metal (loids) such as chromium, mercury and selenium. In this review, we synthesise recent advances in the role of essential metals (e.g. copper) for methanotroph activity, uptake mechanisms alongside their potential to transform toxic heavy metal (loids). Case studies are presented on chromium, selenium and mercury pollution from the tanneries, coal burning and artisanal gold mining, respectively, which are particular problems in the developing economy that we propose may be suitable for remediation by methanotrophs. Video Abstract.
Collapse
Affiliation(s)
- Obulisamy Parthiba Karthikeyan
- School of Biological Sciences & Institute for Global Food Security, Queen’s University Belfast, 19 Chlorine Gardens, Belfast, UK
- Civil and Environmental Engineering, University of Michigan, Ann Arbor, MI USA
- Department of Engineering Technology, College of Technology, University of Houston, Houston, TX USA
| | - Thomas J. Smith
- Biomolecular Sciences Research Centre, Sheffield Hallam University, Sheffield, UK
| | - Shamsudeen Umar Dandare
- School of Biological Sciences & Institute for Global Food Security, Queen’s University Belfast, 19 Chlorine Gardens, Belfast, UK
| | - Kamaludeen Sara Parwin
- Department of Environmental Sciences, Tamil Nadu Agricultural University, Coimbatore, India
| | - Heetasmin Singh
- Department of Chemistry, University of Guyana, Georgetown, Guyana
| | - Hui Xin Loh
- School of Biological Sciences & Institute for Global Food Security, Queen’s University Belfast, 19 Chlorine Gardens, Belfast, UK
| | - Mark R Cunningham
- School of Biological Sciences & Institute for Global Food Security, Queen’s University Belfast, 19 Chlorine Gardens, Belfast, UK
| | - Paul Nicholas Williams
- School of Biological Sciences & Institute for Global Food Security, Queen’s University Belfast, 19 Chlorine Gardens, Belfast, UK
| | - Tim Nichol
- Biomolecular Sciences Research Centre, Sheffield Hallam University, Sheffield, UK
| | | | | | - Deepak Kumaresan
- School of Biological Sciences & Institute for Global Food Security, Queen’s University Belfast, 19 Chlorine Gardens, Belfast, UK
| |
Collapse
|
8
|
Fergala A, AlSayed A, Khattab S, Ramirez M, Eldyasti A. Development of Methane-Utilizing Mixed Cultures for the Production of Polyhydroxyalkanoates (PHAs) from Anaerobic Digester Sludge. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:12376-12387. [PMID: 30339372 DOI: 10.1021/acs.est.8b04142] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The fundamental components required for scaling up the production of biogas-based biopolymers can be provided through a single process, that is, anaerobic digestion (AD). In this research, the possibility of enriching methane-utilizing mixed cultures from the AD process was explored as well as their capability to accumulate polyhydroxyalkanoates (PHAs). For almost 70 days of operation in a fed-batch cyclic mode, the specific growth rate was 0.078 ± 0.005 h-1 and the biomass yield was 0.7 ± 0.08 mg-VSS/mg-CH4. Adjusting the nitrogen levels in AD centrate resulted in results comparable to those obtained with a synthetic medium. The enriched culture could accumulate up to 51 ± 2% PHB. On the other hand, when the culturing medium was supplemented with valeric acid, the enriched bacteria were able to produce polyhydroxybutyrate- co-valerate (PHBV) up to 52 ± 6% with an HV percentage of 33 ± 5%. Increasing the valeric acid concentration in the culturing medium above 100 mg/L decreased the overall amount of PHBV by 60%, whereas the number of HV units incorporated was not affected. Changing the methane-to-oxygen ratio (M/O) from 1:1 to 4:1 caused an almost 80% decline in PHB accumulation. In addition, M/O had a significant effect on the fraction composition of PHBV at different valeric acid concentrations.
Collapse
Affiliation(s)
- Ahmed Fergala
- Department of Civil Engineering, Lassonde School of Engineering , York University , Toronto , Ontario Canada M3J 1P3
| | - Ahmed AlSayed
- Department of Civil Engineering, Lassonde School of Engineering , York University , Toronto , Ontario Canada M3J 1P3
| | - Saif Khattab
- Department of Chemical Engineering , Ryerson University , 350 Victoria Street , Toronto , Ontario Canada M5B 2K3
| | - Megan Ramirez
- Department of Environmental Engineering , Universidad International , Cuernavaca , Morelos , Mexico
| | - Ahmed Eldyasti
- Department of Civil Engineering, Lassonde School of Engineering , York University , Toronto , Ontario Canada M3J 1P3
| |
Collapse
|
9
|
La H, Hettiaratchi JPA, Achari G, Dunfield PF. Biofiltration of methane. BIORESOURCE TECHNOLOGY 2018; 268:759-772. [PMID: 30064899 DOI: 10.1016/j.biortech.2018.07.043] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 07/06/2018] [Accepted: 07/08/2018] [Indexed: 06/08/2023]
Abstract
The on-going annual increase in global methane (CH4) emissions can be largely attributed to anthropogenic activities. However, as more than half of these emissions are diffuse and possess a concentration less than 3% (v/v), physical-chemical treatments are inefficient as an abatement technology. In this regard, biotechnologies, such as biofiltration using methane-oxidizing bacteria, or methanotrophs, are a cost-effective and efficient means of combating diffuse CH4 emissions. In this review, a number of abiotic factors including temperature, pH, water content, packing material, empty-bed residence time, inlet gas flow rate, CH4 concentration, as well biotic factors, such as biomass development, are reviewed based on empirical findings on CH4 biofiltration studies that have been performed in the last decades.
Collapse
Affiliation(s)
- Helen La
- Department of Civil Engineering, Center for Environmental Engineering Research and Education (CEERE), University of Calgary, 2500 University Drive, NW, Calgary, Alberta T2N 1N4 Canada
| | - J Patrick A Hettiaratchi
- Department of Civil Engineering, Center for Environmental Engineering Research and Education (CEERE), University of Calgary, 2500 University Drive, NW, Calgary, Alberta T2N 1N4 Canada
| | - Gopal Achari
- Department of Civil Engineering, Center for Environmental Engineering Research and Education (CEERE), University of Calgary, 2500 University Drive, NW, Calgary, Alberta T2N 1N4 Canada.
| | - Peter F Dunfield
- Department of Biological Sciences, University of Calgary, 2500 University Drive, NW, Calgary, Alberta T2N 1N4 Canada
| |
Collapse
|