scholarly journals Organic Matter Degradation across Ecosystem Boundaries: The Need for a Unified Conceptualization

2020 ◽  
Author(s):  
Dolly N. Kothawala ◽  
Anne M. Kellerman ◽  
Núria Catalán ◽  
Lars J. Tranvik
Keyword(s):  
Organic Matter ◽  
Organic Matter Degradation ◽  
Ecosystem Boundaries

scholarly journals Timescales for the development of methanogenesis and free gas layers in recently-deposited sediments of Arkona Basin (Baltic Sea)

2012 ◽  
Vol 9 (5) ◽  
pp. 1915-1933 ◽  
Author(s):  
J. M. Mogollón ◽  
A. W. Dale ◽  
H. Fossing ◽  
P. Regnier
Keyword(s):  
Organic Matter ◽  
Baltic Sea ◽  
Reactive Transport ◽  
Reaction Pathway ◽  
Organic Matter Degradation ◽  
Muddy Sediment ◽  
Transport Models ◽  
Methane Gas ◽  
Geochemical Profiles ◽  
Arkona Basin

Abstract. Arkona Basin (southwestern Baltic Sea) is a seasonally-hypoxic basin characterized by the presence of free methane gas in its youngest organic-rich muddy stratum. Through the use of reactive transport models, this study tracks the development of the methane geochemistry in Arkona Basin as this muddy sediment became deposited during the last 8 kyr. Four cores are modeled each pertaining to a unique geochemical scenario according to their respective contemporary geochemical profiles. Ultimately the thickness of the muddy sediment and the flux of particulate organic carbon are crucial in determining the advent of both methanogenesis and free methane gas, the timescales over which methanogenesis takes over as a dominant reaction pathway for organic matter degradation, and the timescales required for free methane gas to form.

Beneficial effect of mixture of additives amendment on enzymatic activities, organic matter degradation and humification during biosolids co-composting

2018 ◽  
Vol 247 ◽  
pp. 138-146 ◽  
Author(s):  
Mukesh Kumar Awasthi ◽  
Quan Wang ◽  
Hongyu Chen ◽  
Sanjeev Kumar Awasthi ◽  
Meijing Wang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Beneficial Effect ◽  
Enzymatic Activities ◽  
Organic Matter Degradation

Consequences of nutrient load reductions for carbon and alkalinity dynamics within the region of freshwater influence of River Elbe

2021 ◽  
Author(s):  
Johannes Paetsch ◽  
Helmuth Thomas
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Sulfate Reduction ◽  
Biogeochemical Model ◽  
Time Interval ◽  
Nutrient Loads ◽  
Organic Matter Degradation ◽  
Strong Decrease ◽  
Nitrogen And Phosphorus ◽  
River Elbe

<p>Since the early eighties of the 20<sup>th</sup> century nitrogen and phosphorus loads of the River Elbe, a river entering the North European Shelf at the southeastern coast, have decreased by a factor of about four. This resulted in a reduction of the eutrophication status in the adjacent German Bight and the coastal waters west of Denmark. In addition, benthic carbon and alkalinity pools have changed due to 1- changed carbon loads and, 2- changed decay pathways of benthic organic carbon.</p><p>We investigate the consequences of observed nutrient and organic loads by rivers with a 3D-biogeochemical model including a 3D-early diageneses model within the sediment for the time 1979 - 2014.   </p><p>The results show a strong decrease of benthic carbon rather due to decreasing nutrient loads and subsequent autochthonous biological production than changes in organic loads. The export of inorganic carbon from the sediment is related to the magnitude of benthic organic carbon and cannot explain the strong decrease of the benthic POC pool. During the time until the early nineties aerobic degradation increases, whereas denitrification and sulfate reduction as organic matter degradation pathway decreases.</p><p>Alkalinity production due to benthic organic matter degradation decreases over the first half of the investigated time interval and keeps constant during the second half. Denitrification and sulfate reduction dominate the mechanisms decreasing the alkalinity export. Benthic nitrification consuming alkalinity strongly increases during the first half of the time dampening the decrease of alkalinity export.</p>

scholarly journals The relevance of environment vs. composition on dissolved organic matter degradation in freshwaters

2020 ◽  
Author(s):  
Núria Catalán ◽  
Ada Pastor ◽  
Carles M. Borrego ◽  
Joan Pere Casas‐Ruiz ◽  
Jeffrey A. Hawkes ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Organic Matter Degradation

scholarly journals Distribution Profile of Chemical Elements during the Last 13 Thousand Years from the Sediments of Maloye Yarovoe Lake (Western Siberia, Russia)

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3001
Author(s):  
Marina Kolpakova ◽  
Olga Gaskova ◽  
Svetlana Borzenko ◽  
Sergey Krivonogov ◽  
Olga Naymushina ◽  
...  
Keyword(s):  
Organic Matter ◽  
Western Siberia ◽  
Chemical Elements ◽  
Water Evaporation ◽  
Organic Matter Degradation ◽  
Distribution Profile ◽  
Rock Interaction ◽  
Radiocarbon Dates ◽  
Kulunda Steppe ◽  
Lake Stage

The article presents the studies on understanding the chemical evolution of Maloye Yarovoe lake that is located in the semi-arid landscape of and represent the most widespread chemical type of saline lake (Cl-Na) on the territory of Kulunda steppe (south of Western Siberia). The lake has gone through several changes in its state which are well represented in its sediments: section 1 (4.52–4.97 m) represents the subbase; section 2 (3.0–4.57 m) corresponds to a “shallow lake” stage and contains two sublayers; section 3 (0–2.25 m) illustrates an increase in erosion of the shoreline and corresponds to a “deep lake” stage. The extrapolation of radiocarbon dates suggests that the most significant changes in the state of the lake occurred at about 6.5–7.1 ka BP (transition from a small lake to a large one with intensified coastal erosion) and at about 5.69 and 3.5 ka BP (increase in the organic component). The results of sequential extraction of elements correspond to chemical changes occurred in a certain time of the lake state by changing in their distribution level and fraction type along the core. The results of lake water evaporation and organic matter degradation modelling performed in Phreeqc for oxic and anoxic condition showed the following stages of chemical divides could be expected in case of further lakes desiccation: Halite—Epsomite—Bischofite/Carnalite with possibility of Nahcolite precipitation in carbonate enriched periods (summer and autumn periods of organic matter degradation). Water–rock interaction processes in combination with biogeochemical reactions affect drastically not only the migration features of elements in water and sediments, but also the type of mineral crystallization in lake sediments.

Sign in / Sign up

Export Citation Format

Share Document