Bacterial vs. thermal degradation of algal matter: Analysis from a physicochemical perspective
| Autor: | Sophia Hohlbauch, Arash Abarghani, Drew Griffin, Bailey Bubach, Bo Liu, Mehdi Ostadhassan, Mohammadreza Shokouhimehr, Thomas Gentzis |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
chemistry.chemical_classification
Chemistry 020209 energy Stratigraphy Mudrock chemistry.chemical_element Geology 02 engineering and technology Biodegradation 010502 geochemistry & geophysics 01 natural sciences Anoxic waters Sulfur chemistry.chemical_compound Fuel Technology Telalginite Environmental chemistry 0202 electrical engineering electronic engineering information engineering Kerogen Degradation (geology) Economic Geology Organic matter 0105 earth and related environmental sciences |
| Zdroj: | International Journal of Coal Geology. 223:103465 |
| ISSN: | 0166-5162 |
| DOI: | 10.1016/j.coal.2020.103465 |
| Popis: | Bacteria are ubiquitous in all depositional environments, especially in marine environments where anoxic/euxinic conditions prevail. In such environments, sulfate-reducing bacteria play a critical role to supply sulfur as a biogenic source for H2S through biomass degradation. In the biodegradation process, chemical and mechanical properties of the organic matter alter. In order to document these variations in-situ, selected samples from a deeply buried mudrock (Bakken Formation), were examined through microscopy analysis. Two separate but adjacent telalginite particles were selected; An unaltered telalginite and a bacterially degraded telalginite, which still contains relicts of the parent Tasmanites. A combination of AFM-based IR spectroscopy with high-resolution amplitude-frequency modulation was used to evaluate and compare the physicochemical variations across these two particles at the nanoscale. Results indicate that all aromaticity indexes increase for both particles but at a higher rate as a result of bacterial degradation. Furthermore, it was found that bacterial degradation imposes a major mechanical heterogeneity to the organic matter under study, which was detected through phase imaging and modulus mapping captured from submicron to micron-scale level, which exposed the remnants of the parent Tasmanites. This study reveals that bacterial degradation can accelerate the maturation process, thus the generation of hydrocarbons from the kerogen to happen at the earlier stages of thermal adavance. |
| Databáze: | OpenAIRE |
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