scholarly journals Analysis of methane production pathways in a riparian wetland of a temperate forest catchment, usingδ13C of pore water CH4and CO2

2008 ◽  
Vol 113 (G3) ◽  
Author(s):  
Masayuki Itoh ◽  
Nobuhito Ohte ◽  
Keisuke Koba ◽  
Atsuko Sugimoto ◽  
Makoto Tani
Keyword(s):  
Pore Water ◽  
Methane Production ◽  
Temperate Forest ◽  
Riparian Wetland ◽  
Forest Catchment

scholarly journals A two-dimensional model of the passive coastal margin deep sedimentary carbon and methane cycles

2012 ◽  
Vol 9 (8) ◽  
pp. 2859-2878 ◽  
Author(s):  
D. E. Archer ◽  
B. A. Buffett ◽  
P. C. McGuire
Keyword(s):  
Organic Carbon ◽  
Pore Water ◽  
Continental Margin ◽  
Methane Production ◽  
Production Efficiency ◽  
Dissolved Inorganic Carbon ◽  
Carbon Isotopic Composition ◽  
Scale Model ◽  
Dimensional Model ◽  
Sediment Column

Abstract. We present a new geologic-time and basin-spatial scale model of the continental margin methane cycle. The model, SpongeBOB, is used to simulate evolution of the carbon cycle in a passive sedimentary continental margin in response to changing oceanographic and geologic forcing over a time scale of 200 million years. The geochemistry of the sediment column is altered by the addition of vertical high-permeability channels intended to mimic the effects of heterogeneity in the real sediment column due to faults, and produces results consistent with measured pore-water tracers SO42− and 129I. Pore water dissolved inorganic carbon (DIC) concentrations are consistent with chemical weathering (CaCO3 formation from igneous rocks) at depth within the sediment column. The carbon isotopic composition of the DIC is consistent with a methane production efficiency from particulate organic carbon (POC) of 50%, which is somewhat lower than redox balance with the H / C of organic matter in the model. The hydrate inventory in the model is somewhat less sensitive to temperature than our previous results with a one-dimensional model, quite sensitive to reasonable changes in POC, and extremely sensitive to the ability of methane bubbles to rise within the sediment column, and how far gas-phase methane can get through the sediment column before it redissolves when it reaches undersaturated conditions. Hydrate formation is also sensitive to deep respiration of migrating petroleum. Other phenomena which we simulated had only a small impact on the hydrate inventory, including thermogenic methane production and production/decomposition of dissolved organic carbon.

scholarly journals Ecohydrology and Biogeochemistry in a Temperate Forest Catchment

10.5772/30759 ◽  
2012 ◽  
Author(s):  
Su-Jin Kim ◽  
Hyung Tae ◽  
Kyongha Kim ◽  
Chunghwa Lee
Keyword(s):  
Temperate Forest ◽  
Forest Catchment

scholarly journals Microbially-mediated de-watering and consolidation (“Biodensification”) of oil sands mature fine tailings, amended with agri-business by-products

Nova Scientia ◽  
2020 ◽  
Vol 12 (24) ◽  
Author(s):  
Marcela Cárdenas-Manríquez ◽  
Rozlyn F. Young ◽  
Kathleen M. Semple ◽  
Carmen Li ◽  
Debora Coy ◽  
...  
Keyword(s):  
Pore Water ◽  
Methane Production ◽  
Oil Sands ◽  
Aqueous Suspension ◽  
Surface Mining ◽  
Water Recovery ◽  
Mining Operations ◽  
Fine Tailings ◽  
By Products

Oil sands surface mining operations in northeastern, Alberta, Canada produce enormous volumes of fluid fine tailings, an aqueous suspension of fine clays, sand, unrecovered bitumen, and diluent hydrocarbons. The tailings are deposited and retained on-site in large settling basins where the colloidal solids sediment and consolidate very slowly by gravity and pore water collects at the surface for re-use. Tailings ‘biodensification’, mediated by indigenous microbes that produce methane and/or carbon dioxide, is a phenomenon observed in situ and in vitro whereby tailings with active anaerobic microbial communities consolidate and de-water faster than predicted by gravitational (self-weighted) consolidation alone. To exploit this phenomenon, we used organic amendments to stimulate endogenous anaerobic tailings microorganisms. Tailings from three different operators were amended with agri-business by-products, placed in 100-mL microcosms and 1.5-L settling columns, and monitored for methanogenesis, pore water recovery, and solids densification. Several amendments increased methane production and accelerated biodensification compared to unamended and negative controls. Hydrolyzed canola, blood meal, bone meal and glycerol generally accelerated biodensification, stimulated methane production and supported growth of methanogens and fermentative microbes. Amendment altered the chemistry of the tailings, generally decreasing pH, increasing conductivity and magnesium, potassium, sodium, and bicarbonate concentrations. Biodensification is a potential engineered technology for accelerating water recovery and reducing the volume of stored oil sands tailings.

scholarly journals Methane production correlates positively with methanogens, sulfate-reducing bacteria and pore water acetate at an estuarine brackish-marsh landscape scale

2013 ◽  
Vol 10 (11) ◽  
pp. 18241-18275 ◽  
Author(s):  
C. Tong ◽  
C. X. She ◽  
Y. F. Jin ◽  
P. Yang ◽  
J. F. Huang
Keyword(s):  
Production Rate ◽  
Pore Water ◽  
Methane Production ◽  
Soil Depth ◽  
Landscape Scale ◽  
Brackish Marsh ◽  
Sulfate Reducing ◽  
Brackish Marshes ◽  
Methane Production Rate ◽  
Reducing Bacteria

Abstract. Methane production is influenced by the abundance of methanogens and the availability of terminal substrates. Sulfate-reducing bacteria (SRB) also play an important role in the anaerobic decomposition of organic matter. However, the relationships between methane production and methanogen populations, pore water terminal substrates in estuarine brackish marshes are poorly characterized, and even to our knowledge, no published research has explored the relationship between methane production rate and abundance of SRB and pore water dimethyl sulfide (DMS) concentration. We investigated methane production rate, abundances of methanogens and SRB, concentrations of pore water terminal substrates and electron acceptors at a brackish marsh landscape dominated by Phragmites australis, Cyperus malaccensis and Spatina alterniflora marshes zones in the Min River estuary. The average rates of methane production at a soil depth of 30 cm in the three marsh zones were 0.142, 0.058 and 0.067 μg g−1 d−1, respectively. The abundance of both methanogens and SRB in the soil of the P. australis marsh with highest soil organic carbon content was higher than in the C. malaccensis and S. alterniflora marshes. The abundance of methanogens and SRB in the three soil layers was statistically indistinguishable. Mean pore water DMS concentrations at a soil depth of 30 cm under the S. alterniflora marsh were higher than those in the C. malaccensis and P. australis marshes. Methane production rate increased with the abundance of both methanogens and SRB across three marsh zones together at the landscape scale, and also increased with the concentration of pore water acetate, but did not correlate with concentrations of pore water DMS and dissolved CO2. Our results suggest that, provided that substrates are available in ample supply, methanogens can continue to produce methane regardless of whether SRB are prevalent in estuarine brackish marshes.

scholarly journals Hydrologic effects on methane dynamics in riparian wetlands in a temperate forest catchment

2007 ◽  
Vol 112 (G1) ◽  
Author(s):  
Masayuki Itoh ◽  
Nobuhito Ohte ◽  
Keisuke Koba ◽  
Masanori Katsuyama ◽  
Kana Hayamizu ◽  
...  
Keyword(s):  
Temperate Forest ◽  
Riparian Wetlands ◽  
Forest Catchment ◽  
Methane Dynamics

scholarly journals Estimating methane production rates in bogs and landfills by deuterium enrichment of pore water

2001 ◽  
Vol 15 (4) ◽  
pp. 967-975 ◽  
Author(s):  
D. I. Siegel ◽  
J. R. Chanton ◽  
P. H. Glaser ◽  
L. S. Chasar ◽  
D. O. Rosenberry
Keyword(s):  
Pore Water ◽  
Methane Production ◽  
Production Rates ◽  
Deuterium Enrichment
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