scholarly journals Microbial degradation of terrigenous dissolved organic matter and potential consequences for carbon cycling in brown-water streams

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Christina Fasching ◽  
Barbara Behounek ◽  
Gabriel A. Singer ◽  
Tom J. Battin
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Carbon Cycling ◽  
Microbial Degradation

Invasive plant-derived dissolved organic matter alters microbial communities and carbon cycling in soils

2021 ◽  
pp. 108191
Author(s):  
Morgan Luce McLeod ◽  
Lorinda Bullington ◽  
Cory C. Cleveland ◽  
Johannes Rousk ◽  
Ylva Lekberg
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Microbial Communities ◽  
Carbon Cycling ◽  
Invasive Plant

scholarly journals Photochemical alteration of dissolved organic matter and the subsequent effects on bacterial carbon cycling and diversity

2016 ◽  
Vol 92 (5) ◽  
pp. fiw048 ◽  
Author(s):  
Christian Lønborg ◽  
Mar Nieto-Cid ◽  
Victor Hernando-Morales ◽  
Marta Hernández-Ruiz ◽  
Eva Teira ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Carbon Cycling

Molecular fractionation of dissolved organic matter on ferrihydrite: effects of dissolved cations

2019 ◽  
Vol 16 (2) ◽  
pp. 137 ◽  
Author(s):  
Minqin Liu ◽  
Yang Ding ◽  
Shimeng Peng ◽  
Yang Lu ◽  
Zhi Dang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Carbon Cycling ◽  
Natural Environment ◽  
Divalent Cations ◽  
Ion Cyclotron Resonance ◽  
Underlying Mechanisms ◽  
Cu Ions ◽  
Molecular Fractionation ◽  
Background Electrolytes

Environmental contextCarbon sequestration and dynamics are influenced by adsorptive fractionation of dissolved organic matter (DOM) on minerals. We found that the molecular fractionation of DOM on ferrihydrite was highly dependent on the presence of Na, Ca and Cu ions in water. These results advance our mechanistic understanding of the dynamic behaviour of DOM, and contribute to predicting carbon cycling and contaminant behaviour in the natural environment. AbstractThe adsorptive fractionation of dissolved organic matter (DOM) at the ferrihydrite and water interface is a key geochemical process controlling DOM compositions and reactivity, thus affecting carbon cycling and contaminant behaviour in the environment. However, the effects of cations on DOM fractionation and the underlying mechanisms are poorly understood. In this study, Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) combined with spectroscopic methods were employed to investigate molecular fractionation of DOM on ferrihydrite under different cations in the background electrolytes, including Na, Ca, and Cu ions. The results indicated that DOM fractionation was influenced by the combined effects of cation type, intrinsic molecular property, and extent of DOM adsorption. DOM adsorption on ferrihydrite exhibited the strongest and the weakest fractionation under Na and Ca background electrolytes, respectively. Both Ca and Cu background electrolytes reduced the adsorption of highly unsaturated and phenolic/polyphenolic molecules with high molecular weight and number of O atoms. In addition to the molecular acidity, the complexation of Ca and Cu ions to DOM binding sites and the coagulation effect of divalent cations may affect molecular fractionation. Additionally, DOM fractionation was enhanced with increasing DOM adsorption. Our results contribute to predicting carbon cycling and contaminant behaviour in the natural environment.

Recent advances in structure and reactivity of dissolved organic matter in natural waters

2008 ◽  
Vol 8 (6) ◽  
pp. 615-623 ◽  
Author(s):  
William J. Cooper ◽  
Weihua Song ◽  
Michael Gonsior ◽  
Daina Kalnina ◽  
Barrie M. Peake ◽  
...  
Keyword(s):  
Organic Matter ◽  
Free Radical ◽  
Water Treatment ◽  
Dissolved Organic Matter ◽  
Carbon Cycling ◽  
Natural Waters ◽  
Anthropogenic Sources ◽  
Radical Reactions ◽  
Detailed Knowledge ◽  
Free Radical Reactions

The goal of our research is to better understand the structure and reactivity of natural dissolved organic matter (DOM) in aquatic environments. A more detailed knowledge of these DOM characteristics would lead to a better understanding of carbon cycling in natural waters and processes associated with water treatment using free radical chemistry. Our specific interest in DOM in natural waters is several-fold: 1) the photochemical formation of reactive oxygen species, 2) photobleaching of the DOM in coastal oceans, and 3) using chromophoric DOM (CDOM) as a tracer of water masses and in carbon cycling. Our interest in water treatment is that DOM is the major sink of hydroxyl radicals employed in advanced oxidation processes for the destruction of pollutants and thus adversely affects the efficiency of the process. We are using the techniques of radiation chemistry to explore the fundamental free radical and redox chemistry of DOM. We have initiated a study of the free radical reactions of DOM using isolated fractions of Suwannee River fulvic and humic acids and isolates from various anthropogenic sources. We are also investigating the use of model compounds in an attempt to understand the free radical transients formed from DOM either as a result of free radical reactions or photochemical reactions.

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