Evaluation of Methane Oxidation Efficiency of Two Biocovers: Field and Laboratory Results

Roncato, Camila D.L.; Cabral, Alexandre R.

doi:10.1061/(asce)ee.1943-7870.0000475

Cited by 32 publications

(24 citation statements)

References 28 publications

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“…Biological cover that has been recommended by the authors of [10] can solve the above-mentioned problems. It optimizes the environmental conditions of the cover, enhances the CH 4 oxidation rates, and reduces the CH 4 fluxes emitted from landfills [11][12][13]. Biochar is a porous, organic material produced by the pyrolysis or gasification of waste biomass, and the increased presence of micropores makes it highly preferable for gas adsorption purposes [14].…”

Section: Introductionmentioning

confidence: 99%

Methane Emission Reduction Enhanced by Hydrophobic Biochar-Modified Soil Cover

et al. 2020

Processes

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The microbial oxidation of CH4 in biochar-modified soil cover is considered a potent option for the mitigation of emissions from old landfills or sites containing wastes full of low CH4 generation rates. The mechanism of methane oxidizing bacteria (MOB) can be enhanced by amending the landfill cover soil with biochar, which is recalcitrant to biological degradation and can adsorb CH4 while facilitating the growth and activity of MOB within its porous structure. However, the increase in the permeability coefficient and water content of the cover due to the addition of biochar also affects the methane removal efficiency. A hydrophobic biochar modified by KH-570 was employed to reduce the water content and to promote the diffusion and oxidation of CH4 in the cover. Several series of small-scale column tests were conducted to quantify the CH4 oxidation properties of the landfill cover soil amended with biochar and hydrophobic biochar under different levels of exposed CH4 concentrations (5% and 15%), heights (10–66 cm), and temperatures (15–40 °C). After 30 days of domestication, the removal rate of the hydrophobic biochar-modified soil cover reached 98.8%. The water holding capacity of the cover and the CH4 oxidation efficiency under different moisture contents were investigated in different columns. The hydrophobic biochar-modified soil cover has a weak water holding capacity, low saturated water content, and optimal CH4 oxidation efficiency at this time.

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Section: Introductionmentioning

confidence: 99%

Methane Emission Reduction Enhanced by Hydrophobic Biochar-Modified Soil Cover

et al. 2020

Processes

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“…Several studies have shown that a passive biosystem (where the biogas passes through the cover naturally, without pumping it) installed in the cover system (interim or fi-nal) can be a very effective complement to active systems in reducing fugitive emissions of methane and odorous substances (Abichou et al, 2006a;Cabral et al, 2010a;Capanema et al, 2013;Capanema et al, 2014;Geck et al, 2016;Lucernoni et al, 2016;Roncato and Cabral, 2012;Sadasivam and Reddy, 2014;Scheutz et al, 2009). Most of these studies documented the performance of passive biosystems in temperate climates, while (to the authors' knowledge) no field-scale studies have been performed to document the performance of passive biosystems in Brazil (a tropical country) and employing residual soils.…”

Section: Introductionmentioning

confidence: 99%

Fugitive Methane Emissions From Two Experimental Biocovers Constructed With Tropical Residual Soils: Field Study Using a Large Flux Chamber

et al. 2019

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This study aimed at assessing the response of two experimental passive methane oxidation biocovers (PMOB) installed in a Brazilian landfill located in Guarapuava, State of Paraná. The PMOBs covered an area of 18 m² each, and were 0.70-m-thick. The first PMOB (control subarea) was constructed using the same soil used to cover closed landfill cells, i.e. a typical residual soil. The second PMOB (enriched subarea) was constructed with a mixture of the residual soil and mature compost, with a resulting organic matter content equal to 4.5%. CH 4 and CO 2 surface fluxes were measured in a relatively large (4.5 m²) static chamber. CH 4 , CO 2 and O 2 concentrations were also measured at different depths (0.10, 0.20, 0.25 and 0.30 m) within PMOBs. The concentrations from the raw biogas were also measured. Methane oxidation efficiencies (Eff ox) were estimated based on the CO 2 /CH 4 ratio. The average CH 4 and CO 2 concentrations in the raw biogas (42% and 32%, respectively) for the 16 campaigns corroborated those typically found in Brazilian landfills. Lower CH 4 fluxes were obtained within the enriched subarea (average of 20 g.m-2 .d-1), while the fluxes in the control subarea averaged 34 g.m-2 .d-1. Eff ox values averaged 42% for the control subarea and 80% for the enriched one. The results indicate that there is a great potential to reduce landfill gas (LFG) emissions by using passive methane oxidation biosystems composed of enriched substrates (with a higher content of organic matter).

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“…To date, extensive research conducted in this field highlights the importance of employing organic rich biocover materials to improve the microbial methane oxidation capacity of landfill cover systems (Park et al, 2004;Stern et al, 2007;Huber-Humer et al, 2008Scheutz et al, 2011;Roncato and Cabral, 2011). However, researchers have not yet explored the process of methane adsorption within landfill cover systems that can also contribute to methane mitigation.…”

Section: Introductionmentioning

confidence: 99%