“…These findings indicate that the domestication of MOB over a period of time has gradually adapted to the new environment. Similar results were observed by Sadasivam and Reddy [18,19], that the CH 4 oxidation efficiency would be highly shown in landfill cover soil amended with biochar. In addition, landfill cover soil amended with hydrophobic biochar also has the same good CH 4 oxidation capacity.…”
Section: Ch 4 Oxidation In the Columnssupporting
confidence: 88%
“…When the influx CH 4 concentration was 5%, Col. 2 had the lowest CH 4 concentration and Col. 3 had the highest one in the beginning. The increased levels of phosphorus, potassium, and organic matter in the soil are conducive to the growth and reproduction of CH 4 oxidizing bacteria due to the biochar addition; biochar also has an excellent adsorption effect [17][18][19]. However, the residual toxicity of the modifier in the biochar may affect the activity of the methane oxidizing bacteria (MOB).…”
Section: Ch 4 Oxidation In the Columnsmentioning
confidence: 99%
“…Compared with the environmental impact of burning straw in the open air, the total amount of biogas produced during the conversion of rice straw into biochar each year can provide a value of 7.27 × 10 9 kW • h for electricity production, which can reduce the CO 2 emissions from coal combustion by 7.78 × 10 6 t. Therefore, biochar is an economical and environmentally friendly material [15]. Hilger and Humer [16], Yargicoglu et al [17], and Sadasivam and Reddy [18,19] indicated that CH 4 oxidation can be seen in landfill cover soil amended with biochar. Yaghoubi [1] also reported that the soil mixture permeability coefficient increases as the biochar content increases.…”
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.
“…These findings indicate that the domestication of MOB over a period of time has gradually adapted to the new environment. Similar results were observed by Sadasivam and Reddy [18,19], that the CH 4 oxidation efficiency would be highly shown in landfill cover soil amended with biochar. In addition, landfill cover soil amended with hydrophobic biochar also has the same good CH 4 oxidation capacity.…”
Section: Ch 4 Oxidation In the Columnssupporting
confidence: 88%
“…When the influx CH 4 concentration was 5%, Col. 2 had the lowest CH 4 concentration and Col. 3 had the highest one in the beginning. The increased levels of phosphorus, potassium, and organic matter in the soil are conducive to the growth and reproduction of CH 4 oxidizing bacteria due to the biochar addition; biochar also has an excellent adsorption effect [17][18][19]. However, the residual toxicity of the modifier in the biochar may affect the activity of the methane oxidizing bacteria (MOB).…”
Section: Ch 4 Oxidation In the Columnsmentioning
confidence: 99%
“…Compared with the environmental impact of burning straw in the open air, the total amount of biogas produced during the conversion of rice straw into biochar each year can provide a value of 7.27 × 10 9 kW • h for electricity production, which can reduce the CO 2 emissions from coal combustion by 7.78 × 10 6 t. Therefore, biochar is an economical and environmentally friendly material [15]. Hilger and Humer [16], Yargicoglu et al [17], and Sadasivam and Reddy [18,19] indicated that CH 4 oxidation can be seen in landfill cover soil amended with biochar. Yaghoubi [1] also reported that the soil mixture permeability coefficient increases as the biochar content increases.…”
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.
“…As for methane production, no statistically relevant differences were observed among treatments (Fig. 2 ), although in all biochar-supplemented bottles methane production (as determined from chromatographic analysis carried out on gas-phase samples) was slightly delayed with respect to the unamended controls, consistently with the reported capacity of biochar to adsorb methane gas [ 58 ]. Fig.…”
BackgroundRecent studies have suggested that addition of electrically conductive biochar particles is an effective strategy to improve the methanogenic conversion of waste organic substrates, by promoting syntrophic associations between acetogenic and methanogenic organisms based on interspecies electron transfer processes. However, the underlying fundamentals of the process are still largely speculative and, therefore, a priori identification, screening, and even design of suitable biochar materials for a given biotechnological process are not yet possible.ResultsHere, three charcoal-like products (i.e., biochars) obtained from the pyrolysis of different lignocellulosic materials, (i.e., wheat bran pellets, coppiced woodlands, and orchard pruning) were tested for their capacity to enhance methane production from a food waste fermentate. In all biochar-supplemented (25 g/L) batch experiments, the complete methanogenic conversion of fermentate volatile fatty acids proceeded at a rate that was up to 5 times higher than that observed in the unamended (or sand-supplemented) controls. Fluorescent in situ hybridization analysis coupled with confocal laser scanning microscopy revealed an intimate association between archaea and bacteria around the biochar particles and provided a clear indication that biochar also shaped the composition of the microbial consortium. Based on the application of a suite of physico-chemical and electrochemical characterization techniques, we demonstrated that the positive effect of biochar is directly related to the electron-donating capacity (EDC) of the material, but is independent of its bulk electrical conductivity and specific surface area. The latter properties were all previously hypothesized to play a major role in the biochar-mediated interspecies electron transfer process in methanogenic consortia.ConclusionsCollectively, these results of this study suggest that for biochar addition in anaerobic digester operation, the screening and identification of the most suitable biochar material should be based on EDC determination, via simple electrochemical tests.Electronic supplementary materialThe online version of this article (10.1186/s13068-017-0994-7) contains supplementary material, which is available to authorized users.
“…Several studies have been carried out to investigate the effects of different factors (e.g., moisture content, cover thickness, temperature and methane flow rate) with regards to http://dx.doi.org/10.1016/j.wasman.2015.06.042 0956-053X/Ó 2015 Elsevier Ltd. All rights reserved. methane oxidation rate in biocovers (Perdikea et al, 2008;Abichou et al, 2014;Sadasivam and Reddy, 2015;Mei et al, 2015;Zhang et al, 2015). For example, Perdikea et al (2008) investigated the performance of thin biocovers for oxidizing methane emissions in a bioreactor landfill under various moisture contents, cover thicknesses, methane flow rates and compost-to-sawdust ratios by conducting column experiments.…”
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
