Natural photodegradation by UV-B of dissolved organic matter of different decomposing plant sources to readily degradable fatty acids

Dissolved organic matter is an important component of the global carbon cycle that allows the distribution of carbon and nutrients. Therefore, analysis of soil dissolved organic matter helps us to better understand climate change impacts as it is the most dynamic and reactive fraction in terrestrial ecosystems. Its characterization at the molecular level is still challenging due to complex mixtures of hundreds of compounds at low concentration levels in percolating water. This work presents simple methods, such as thermochemolysis– or derivatization–gas chromatography, as an alternative for the analysis of fatty acids in dissolved organic matter without any purification step. The variables of the protocols were examined to optimize the processing conditions for the C9–C18 range. As a proof of concept, fatty acid distributions of soil percolating water samples from a long-term field experiment were successfully assessed. The variability of dissolved organic acid distributions was pronounced through depth profile and soil treatment but no major change in composition was observed. However, although the optimization was done from C9 to C18, detection within the C6-C32 fatty acids range was performed for all samples.

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Hydroxy fatty acids in marine dissolved organic matter as indicators of bacterial membrane material

Organic Geochemistry ◽

10.1016/s0146-6380(02)00189-4 ◽

2003 ◽

Vol 34 (6) ◽

pp. 857-868 ◽

Cited By ~ 57

Author(s):

Stuart G. Wakeham ◽

Tamara K. Pease ◽

Ronald Benner

Keyword(s):

Fatty Acids ◽

Organic Matter ◽

Dissolved Organic Matter ◽

Hydroxy Fatty Acids ◽

Bacterial Membrane ◽

Membrane Material

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Production and transformation of volatile fatty acids from sludge subjected to hydrothermal treatment

Water Science & Technology ◽

10.2166/wst.2001.0600 ◽

2001 ◽

Vol 44 (10) ◽

pp. 129-135 ◽

Cited By ~ 42

Author(s):

A. Shanableh ◽

S. Jones

Keyword(s):

Fatty Acids ◽

Organic Matter ◽

Acetic Acid ◽

Dissolved Organic Matter ◽

Hydrothermal Treatment ◽

Propionic Acid ◽

Volatile Fatty Acids ◽

Cod Removal ◽

The Other ◽

Maximum Accumulation

The production of useful organic matter from sludge expands the potential for utilizing the product as a resource. This paper is focused on the accumulation and removal of volatile fatty acids (VFAs) produced from primary, secondary and a mixture of both sludges using hydrothermal treatment with and without the use of oxidants. The results confirmed that the maximum accumulation of VFAs was achieved at moderate hydrothermal treatment temperatures below 200°C, and was dependent on the composition of sludge and the amount of oxidant used for treatment. The maximum accumulation reached 0.26-0.36 mg VFAs as COD per mg VS from the three sludge types. Acetic acid dominated the VFAs and was followed by propionic acid, with the other VFAs accounting for less than 5% of the total VFAs. As hydrothermal treatment progressed in terms of COD removal, the contribution of acetic acid to the total VFAs increased while the contributions of the other VFAs decreased. The VFAs constituted a major component of the accumulated dissolved organic matter, which reached a maximum of 0.5-0.7 mg soluble COD per mg VS from the three sludge types.

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Modeling the action of anaerobic biofilm

Reports of the National Academy of Sciences of Ukraine ◽

10.15407/dopovidi2021.06.052 ◽

2021 ◽

pp. 52-58

Author(s):

V. L. Poliakov

Keyword(s):

Fatty Acids ◽

Organic Matter ◽

Dissolved Organic Matter ◽

Volatile Fatty Acids ◽

Analytic Solution ◽

Mathematical Problem ◽

Approximate Analytic Solution ◽

Organic Substrates ◽

Vital Activity ◽

Stage Process

A mathematical problem of the action of a representative biofilm in the absence of oxygen is formulated. The anaerobic process of decomposition of a dissolved organic matter is considered as a two-stage process, proceeding due to the vital activity of two groups of microorganisms. An approximate analytic solution allowing one to calculate the concentration and consumption of primary and secondary organic substrates with minimal errors has been obtained. On test examples, their rates of transfer through the biofilm surface are determined, and the possibility of the movement of volatile fatty acids in both directions is discussed.

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