scholarly journals Marine sedimentary organic matter : delineation of marine and terrestrial sources through radiocarbon dating; and the role of organic sulfur in early petroleum generation

1996 ◽  
Author(s):  
Bryan C. Benitez-Nelson
Keyword(s):  
Organic Matter ◽  
Radiocarbon Dating ◽  
Sedimentary Organic Matter ◽  
Organic Sulfur ◽  
Petroleum Generation

Organic sulfur and organic matter redox processes contribute to electron flow in anoxic incubations of peat

2016 ◽  
Vol 13 (5) ◽  
pp. 816 ◽  
Author(s):  
Zhi-Guo Yu ◽  
Jörg Göttlicher ◽  
Ralph Steininger ◽  
Klaus-Holger Knorr
Keyword(s):  
Carbon Dioxide ◽  
Organic Matter ◽  
Electron Acceptor ◽  
Electron Acceptors ◽  
Organic Sulfur ◽  
Co2 Production ◽  
Bacterial Sulfate Reduction ◽  
Sulfur Species ◽  
Ch4 Production

Environmental contextThe extent to which organic matter decomposition generates carbon dioxide or methane in anaerobic ecosystems is determined by the presence or absence of particular electron acceptors. Evaluating carbon dioxide and methane production in anaerobic incubation of peat, we found that organic matter predominated as an electron acceptor over considered inorganic electron acceptors. We also observed changes in organic sulfur speciation suggesting a contribution of organic sulfur species to the electron-accepting capacity of organic matter. AbstractAn often observed excess of CO2 production over CH4 production in freshwater ecosystems presumably results from a direct or indirect role of organic matter (OM) as electron acceptor, possibly supported by a cycling of oxidised and reduced sulfur species. To confirm the role of OM electron-accepting capacities (EACOM) in anaerobic microbial respiration and to elucidate internal sulfur cycling, peat soil virtually devoid of inorganic electron acceptors was incubated under anaerobic conditions. Thereby, production of CO2 and CH4 at a cumulative ratio of 3.2:1 was observed. From excess CO2 production and assuming a nominal oxidation state of carbon in OM of zero, we calculated a net consumption rate of EACOM of 2.36µmol electron (e–)cm–3day–1. Addition of sulfate (SO42–) increased CO2 and suppressed CH4 production. Moreover, subtracting the EAC provided though SO42–, net consumption rates of EACOM had increased to 3.88–4.85µmol e–cm–3day–1, presumably owing to a re-oxidation of sulfide by OM at sites otherwise not accessible for microbial reduction. As evaluated by sulfur K-edge X-ray absorption near-edge structure spectroscopy, bacterial sulfate reduction presumably involved not only a recycling of inorganic sulfur species, but also a sulfurisation of OM, yielding reduced organic sulfur, and changes in oxidised organic sulfur species. Organic matter thus contributes to anaerobic respiration: (i) directly by EAC of redox-active functional groups; (ii) directly by oxidised organic sulfur; and (iii) indirectly by re-oxidation of sulfide to maintain bacterial sulfate reduction.

scholarly journals ANALISIS KEBUTUHAN OKSIGEN UNTUK DEKOMPOSISI BAHAN ORGANIK SEDIMEN DI KAWASAN MANGROVE DESA BEDONO DEMAK

2016 ◽  
Vol 5 (4) ◽  
pp. 285-292
Author(s):  
Mia Arista Sari ◽  
Pujiono Wahyu Purnomo ◽  
Haeruddin Haeruddin
Keyword(s):  
Organic Matter ◽  
Oxygen Demand ◽  
Sedimentary Organic Matter ◽  
Oxygen Requirement ◽  
Ph Values ◽  
Randomized Design ◽  
Decomposition Of Organic Matter ◽  
Completely Randomized Design ◽  
Organic Deposits

ABSTRAK Salah satu peran penting mangrove bagi kehidupan biota akuatik adalah sebagai penyedia nutrien dari bahan organik yang dihasilkan. Proses dekomposisi bahan organik membutuhkan oksigen dan bantuan bakteri. Apabila kadar oksigen berkurang maka dapat mempengaruhi proses dekomposisi dan akhirnya dapat berpengaruh terhadap kehidupan bentos yang ada. Tujuan dari penelitian adalah  mengetahui kebutuhan oksigen yang digunakan dalam proses dekomposisi bahan organik pada kawasan mangrove. Penelitian bersifat eksperimental terhadap deposit bahan organik. Penelitian mengacu pada rancangan acak lengkap dengan 3 perlakuan (deposit organik mangrove padat, sedang, dan jarang) yang masing – masing diulang 3 kali. Penelitian dilakukan di kawasan mangrove desa Bedono, Demak. Peubah utama yang diukur adalah Disolved Oxygen, bahan organik sedimen secara berkala pada jam ke- 0, 12, 24, 36, 48, 60 dan 66. Peubah tambahan yang diukur adalah kelimpahan bakteri. Diukur penurunan Disolved Oxigen pada waktu tertentu. Diukur pula nilai bahan organik sedimen dan kelimpahan koloni bakteri. Hasil yang didapat yaitu nilai kebutuhan oksigen sedimen tertinggi pada stasiun 1 dengan kisaran 1,3 – 3,5. Nilai kebutuhan oksigen sedimen pada stasiun 2 berkisar antara 1,2 – 2,2 dan nilai kebutuhan oksigen sedimen pada stasiun 3 berkisar antara 0,8 - 2,7. Hasil kelimpahan koloni bakteri pada stasiun 1 berkisar antara 1 x 1011 – 1,5 x 1011Cfu/ml. Stasiun 2 berkisar antara 2 x 1011 - 22 x 1011Cfu/ml dan stasiun 3 berkisar antara 1 x 1011 - 2 x 1011Cfu/ml. Kualitas perairan seperti temperatur berikisar antara 27 - 32 ºC. Nilai salinitas beriksar antara 25 - 29‰ dan nilai pH berkisar antara 7 - 8. Kata kunci: Oksigen; Bahan Organik; Sedimen; Dekomposisi ABSTRACT One important role of mangrove for aquatic biota is a provider of nutrients from organic matter produced. The process of decomposition of organic matter need oxygen and help the bacteria. When oxygen levelsdecreases, it can affect the decomposition process and can ultimately affect the existing benthic life. The purpose of the research was to determine the need of oxygen used in the decomposition of organic matter in the mangrove areas. It is a experimental research on the deposit of organic material. The research refers to a completely randomized design with 3 treatments (dense mangrove organic deposits, medium, and rare) that eachs repeated three times. Research conducted in the mangrove areas Bedono village, Demak. The main variables measured were Disolved Oxygen, sedimentary organic matter on a regular basis on the hour 0, 12, 24, 36, 48, 60 and 66. Additional variables that measured the abundance of bacteria.MeasuredDisolvedOxigen decline at a certain time. Measured the value of sedimentary organic matter and the abundance of bacterial colonies. The result is the highest value of the oxygen requirement of sediment at station 1 is in the range of 1,3 to 3,5. The value of the oxygen requirement of sediment at station 2 ranged from 1,2 to 2,2 and the value ofsediment oxygen demand of the three stations ranged from 0,8 to 2,7. The result of the abundance of bacteria colonies from the at station 1 range from 1 x 1011 to 1,5 x 1011Cfu/ml. Station 2 ranging from 2 x 1011 -22 x 1011Cfu/ml and three stations ranged between 1 x 1011 -2 x 1011Cfu/ml. Water quality  such as temperature ranged from 27 - 32 ºC. Salinity value ranged from 25 - 29 ‰ and pH values ranged from 7-8.                                                                                                                              Keywords: Oxygen; Organic Matter; Sediment; Decompotition

The Role of Salt Marsh Structure in the Distribution of Surface Sedimentary Organic Matter

2015 ◽  
Vol 39 (1) ◽  
pp. 108-122 ◽  
Author(s):  
Si Chen ◽  
Raymond Torres ◽  
Miguel A. Goñi
Keyword(s):  
Organic Matter ◽  
Salt Marsh ◽  
Sedimentary Organic Matter

scholarly journals Composition and sources of sedimentary organic matter in the deep Eastern Mediterranean Sea

2015 ◽  
Vol 12 (13) ◽  
pp. 9935-9989 ◽  
Author(s):  
R. Pedrosa-Pàmies ◽  
C. Parinos ◽  
A. Sanchez-Vidal ◽  
A. Gogou ◽  
A. Calafat ◽  
...  
Keyword(s):  
Organic Matter ◽  
Mediterranean Sea ◽  
Eastern Mediterranean ◽  
Sedimentary Organic Matter ◽  
Eastern Mediterranean Sea ◽  
Deep Sea Sediment ◽  
Fine Grained ◽  
Causative Factors ◽  
The Impact

Abstract. Surface sediments collected from deep slopes and basins (1018–4087 m depth) of the oligotrophic Eastern Mediterranean Sea have been analysed for bulk elemental and isotopic composition of organic carbon, total nitrogen and selected lipid biomarkers, jointly with grain size distribution and other geochemical proxies. The distribution and sources of sedimentary organic matter (OM) have been subsequently assessed and general environmental variables, such as water depth and currents, have been examined as causative factors of deep-sea sediment characteristics. Lithogenic and biogenic carbonates are the dominant sedimentary fractions, while both bulk and molecular organic tracers reflect a mixed contribution from autochthonous and allochthonous sources for the sedimentary OM, as indicated by relatively degraded marine OM, terrestrial plant waxes and anthropogenic OM including degraded petroleum by-products, respectively. Wide regional variations have been observed amongst the studied proxies, which reflect the multiple factors controlling sedimentation in the deep Eastern Mediterranean Sea. Our findings highlight the role of deep Eastern Mediterranean basins as depocentres of organic-rich fine-grained sediments (mean 5.4 ± 2.4 μm), with OM accumulation and burial due to aggregation mechanisms and hydrodynamic sorting. A multi-proxy approach is hired to investigate the biogeochemical composition of sediment samples, which sheds new light on the sources and transport mechanisms along with the impact of preservation vs. diagenetic processes on the composition of sedimentary OM in the deep basins of the oligotrophic Eastern Mediterranean Sea.

scholarly journals Uranium Deposits of Erlian Basin (China): Role of Carbonaceous Debris Organic Matter and Hydrocarbon Fluids on Uranium Mineralization

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 532
Author(s):  
Lin-Fei Qiu ◽  
Xi-De Li ◽  
Wu-Sheng Liu ◽  
Bao-Qun Hu ◽  
Long Gao ◽  
...  
Keyword(s):  
Organic Matter ◽  
Uranium Mineralization ◽  
Sedimentary Organic Matter ◽  
Raman Spectroscopic ◽  
Laser Raman ◽  
Two Stages ◽  
Relationship Of ◽  
Oil Gas ◽  
Erlian Basin

The relationship of sedimentary organic matter, oil-gas and sandstone-type uranium (U) deposits is the key problem of U-mineralization. Whether migrate hydrocarbons participate in U-mineralization is still a controversy. Typical U deposits of the Erlian Basin in northeast China have been investigated through detailed petrography, mineralogical, micro spectroscopic, organic geochemical and C-isotope studies. Petrographic observations, Microscopic Laser Raman Spectroscopic, Infrared Spectroscopic and Scanning Electron Microscope analyses indicated there are three types of organic matter (including carbonaceous debris and migrated hydrocarbons). A significant amount of uranium was associated with pyrites, clay minerals and carbonaceous debris organic matter, either coexisted with hydrocarbon fluids. There are at least two stages mineralization events, stage Ⅰ is related to sedimentary organic matter (syngenetic pre-enrichment stage), and stage Ⅱ is related to mobile hydrocarbon fluids (main mineralization stage). Therefore, our results support that migrated hydrocarbons were involved as a reducing agent for the main uranium mineralization after synsedimentary mineralization.

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