Interactions between Kaolinite, Organic Matter, and Potassium Compounds at Elevated Temperatures during Pyrolysis of Caking Coal and Its Density-Separated Fractions

Abstract. Microbial extracellular enzymatic activity (EEA) is the rate-limiting step in the degradation of organic matter in the oceans. These extracellular enzymes exist in two forms: cell-bound, which are attached to the microbial cell wall, and cell-free, which are completely free of the cell. Contrary to previous understanding, cell-free extracellular enzymes make up a substantial proportion of the total marine EEA. Little is known about these abundant cell-free enzymes, including what factors control their activity once they are away from their sites (cells). Experiments were run to assess how cell-free enzymes (excluding microbes) respond to ultraviolet radiation (UVR) and temperature manipulations, previously suggested as potential control factors for these enzymes. The experiments were done with New Zealand coastal waters and the enzymes studied were alkaline phosphatase (APase), β-glucosidase, (BGase), and leucine aminopeptidase (LAPase). Environmentally relevant UVR (i.e. in situ UVR levels measured at our site) reduced cell-free enzyme activities by up to 87 % when compared to controls, likely a consequence of photodegradation. This effect of UVR on cell-free enzymes differed depending on the UVR fraction. Ambient levels of UV radiation were shown to reduce the activity of cell-free enzymes for the first time. Elevated temperatures (15 °C) increased the activity of cell-free enzymes by up to 53 % when compared to controls (10 °C), likely by enhancing the catalytic activity of the enzymes. Our results suggest the importance of both UVR and temperature as control mechanisms for cell-free enzymes. Given the projected warming ocean environment and the variable UVR light regime, it is possible that there could be major changes in the cell-free EEA and in the enzymes contribution to organic matter remineralization in the future.

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Diamondoids and Thiadiamondoids Generated From Hydrothermal Pyrolysis of Crude Oil and TSR Experiments

10.21203/rs.3.rs-875372/v1 ◽

2021 ◽

Author(s):

Yanyan Peng ◽

Chunfang Cai ◽

Chenchen Fang ◽

Liangliang Wu ◽

Jinzhong Liu ◽

...

Keyword(s):

Organic Matter ◽

Crude Oil ◽

Elevated Temperatures ◽

Source Rocks ◽

Chemical Alteration ◽

Thermal Maturation ◽

Direct Reactions ◽

New Generation ◽

Oil Cracking ◽

New Formula

Abstract Diamondoid compounds are widely used to reflect thermal maturation of high mature source rocks or oils and oil cracking extents. However, diamondoids and thiadiamondoids were demonstrated to have newly been generated and decomposed in our hydrothermal pyrolysis of crude oil and TSR experiments. Our results show that adamantanes and diamantanes are generated primarily within the maturity range 0.48–2.1% and 1.2–3.0% EasyRo, respectively. Their formation is enhanced and the decomposition of diamantanes obviously lags behind at elevated temperatures compared with anhydrous experiments. MDI, EAI, DMAI-1, DMDI-2 may serve as reliable maturity proxies at > ca.1.0% EasyRo, and other isomerization indices (TMAI-1, TMAI-2 and DMAI-2) are effective for the highly mature organic matter at EasyRo > 2.0%. The extent of oil cracking (EOC) calculated from the broadly used 3-+4-MD method (Dahl et al., 1999) is proven to overestimate, especially for highly cracked samples due to the new generation of 3-+4-MD. Still, it can be corrected using a new formula at <3.0% EasyRo. Other diamondoid-related indices (e.g. EAI, DMDI-2, As/Ds, MAs/MDs, DMAs/DMDs, and DMAs/MDs) can also be used to estimate EOC. However, these indices cannot be applied to TSR-altered petroleum. TSR is experimentally confirmed to generate diamantanes and thiaadmantanes at 1.81% EasyRo via direct reactions of reduced S species with hydrocarbons and accelerate the decomposition of diamantanes at > 3.0% EasyRo compared with thermal chemical alteration (TCA).

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Facile synthesis of graphene wool doped with oleylamine-capped silver nanoparticles (GW-αAgNPs) for water treatment applications

Applied Water Science ◽

10.1007/s13201-021-01493-3 ◽

2021 ◽

Vol 11 (11) ◽

Author(s):

Adedapo O. Adeola ◽

Gugu Kubheka ◽

Evans M. N. Chirwa ◽

Patricia B. C. Forbes

Keyword(s):

Silver Nanoparticles ◽

Organic Matter ◽

Adsorption Capacity ◽

Natural Organic Matter ◽

Elevated Temperatures ◽

Maximum Adsorption Capacity ◽

Facile Synthesis ◽

Gram Positive ◽

Gram Negative ◽

Process Economics

AbstractThe facile synthesis of graphene wool doped with oleylamine-capped silver nanoparticles (GW-αAgNP) was achieved in this study. The effect of concentration, pH, temperature and natural organic matter (NOM) on the adsorption of a human carcinogen (benzo(a)pyrene, BaP) was evaluated using the doped graphene wool adsorbent. Furthermore, the antibacterial potential of GW-αAgNP against selected drug-resistant Gram-negative and Gram-positive bacteria strains was evaluated. Isotherm data revealed that adsorption of BaP by GW-αAgNP was best described by a multilayer adsorption mechanism predicted by Freundlich model with least ERRSQ < 0.79. The doping of graphene wool with hydrophobic AgNPs coated with functional moieties significantly increased the maximum adsorption capacity of GW-αAgNP over GW based on the qmax and qm predicted by Langmuir and Sips models. π-π interactions contributed to sorbent-sorbate interaction, due to the presence of delocalized electrons. GW-αAgNP-BaP interaction is a spontaneous exothermic process (negative $$\Delta H^\circ$$ Δ H ∘ and $$\Delta G)$$ Δ G ) , with better removal efficiency in the absence of natural organic matter (NOM). While GW is more feasible with higher maximum adsorption capacity (qm) at elevated temperatures, GW-αAgNP adsorption capacity and efficiency is best at ambient temperature, in the absence of natural organic matter (NOM), and preferable in terms of energy demands and process economics. GW-αAgNP significantly inhibited the growth of Gram-negative Pseudomonas aeruginosa and Gram-positive Bacillus subtilis strains, at 1000 mg/L dosage in preliminary tests, which provides the rationale for future evaluation of this hybrid material as a smart solution to chemical and microbiological water pollution.

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Diamondoids and thiadiamondoids generated from hydrothermal pyrolysis of crude oil and TSR experiments

Scientific Reports ◽

10.1038/s41598-021-04270-z ◽

2022 ◽

Vol 12 (1) ◽

Author(s):

Yanyan Peng ◽

Chunfang Cai ◽

Chenchen Fang ◽

Liangliang Wu ◽

Jinzhong Liu ◽

...

Keyword(s):

Organic Matter ◽

Crude Oil ◽

Elevated Temperatures ◽

Source Rocks ◽

Natural Conditions ◽

Chemical Alteration ◽

Direct Reactions ◽

New Generation ◽

Oil Cracking ◽

New Formula

AbstractDiamondoid compounds are widely used to reflect thermal maturation of high mature source rocks or oils and oil cracking extents. However, diamondoids and thiadiamondoids were demonstrated to have newly been generated and decomposed in our hydrothermal pyrolysis of crude oil and TSR experiments. Our results show that adamantanes and diamantanes are generated primarily within the maturity range 0.48–2.1% and 1.2–3.0% EasyRo, respectively. Their formation is enhanced and the decomposition of diamantanes obviously lags at elevated temperatures compared with anhydrous experiments. MDI, EAI, DMAI-1, DMDI-2 may serve as reliable maturity proxies at > ca.1.0% EasyRo, and other isomerization indices (TMAI-1, TMAI-2 and DMAI-2) are effective for the highly mature organic matter at EasyRo > 2.0%. The extent of oil cracking (EOC) calculated from the broadly used (3- + 4-) MD method (Dahl et al. in Nature 399:54–56, 1999) is proven to overestimate, especially for highly cracked samples due to the new generation of (3- + 4-) MD. Still, it can be corrected using a new formula at < 3.0% EasyRo. Other diamondoid-related indices (e.g., EAI, DMDI-2, As/Ds, MAs/MDs, DMAs/DMDs, and DMAs/MDs) can also be used to estimate EOC. However, these indices cannot be applied to TSR-altered petroleum. TSR is experimentally confirmed to generate diamantanes and thiaadmantanes at 1.81% EasyRo likely via direct reactions of reduced S species with hydrocarbons and accelerate the decomposition of diamantanes at > 2.62% EasyRo compared with thermal chemical alteration (TCA). More studies are needed to assess specific mechanisms for the formation of thiadiamondoids under natural conditions.

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Enhanced decomposition offsets enhanced productivity and soil carbon accumulation in coastal wetlands responding to climate change

Biogeosciences ◽

10.5194/bg-8-987-2011 ◽

2011 ◽

Vol 8 (4) ◽

pp. 987-993 ◽

Cited By ~ 67

Author(s):

M. L. Kirwan ◽

L. K. Blum

Keyword(s):

Organic Matter ◽

Soil Carbon ◽

Sea Level Rise ◽

Sea Level ◽

Elevated Co2 ◽

Coastal Wetlands ◽

Elevated Temperatures ◽

Carbon Accumulation ◽

Measured Temperature ◽

Elevated Co2 And Temperature

Abstract. Coastal wetlands are responsible for about half of all carbon burial in oceans, and their persistence as a valuable ecosystem depends largely on the ability to accumulate organic material at rates equivalent to relative sea level rise. Recent work suggests that elevated CO2 and temperature warming will increase organic matter productivity and the ability of marshes to survive sea level rise. However, we find in a series of preliminary experiments that organic decomposition rates increase by about 20% per degree of warming. Our measured temperature sensitivity is similar to studies from terrestrial systems, three times as high as the response of salt marsh productivity to temperature warming, and greater than the productivity response associated with elevated CO2 in C3 marsh plants. Although the experiments were simple and of short duration, they suggest that enhanced CO2 and warmer temperatures could actually make marshes less resilient to sea level rise, and tend to promote a release of soil carbon. Simple projections indicate that elevated temperatures will increase rates of sea level rise more than any acceleration in organic matter accumulation, suggesting the possibility of a positive feedback between climate, sea level rise, and carbon emissions in coastal environments.

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Comparison of I/S Transformation and Maturity of Organic Matter at Elevated Temperatures

Clays and Clay Minerals ◽

10.1346/ccmn.1993.0410206 ◽

1993 ◽

Vol 41 (2) ◽

pp. 178-183 ◽

Cited By ~ 11

Author(s):

B. Velde

Keyword(s):

Organic Matter ◽

Elevated Temperatures

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Effect of multivalent cations, temperature and aging on soil organic matter interfacial properties

Environmental Chemistry ◽

10.1071/en14008 ◽

2014 ◽

Vol 11 (6) ◽

pp. 709 ◽

Cited By ~ 12

Author(s):

Dörte Diehl ◽

Tatjana Schneckenburger ◽

Jaane Krüger ◽

Marc-Oliver Goebel ◽

Susanne K. Woche ◽

...

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Aging Time ◽

Surface Properties ◽

Elevated Temperatures ◽

Peat Soil ◽

Interfacial Properties ◽

Contact Angles ◽

Water Dispersible ◽

Cross Links

Environmental context The supramolecular structure and resulting physicochemical properties of soil organic matter (SOM) significantly control storage and buffer functions of soils, e.g. for nutrients, organic molecules and water. Multivalent cations, able to form complexes, are suggested to form inter- and intramolecular cross-links in SOM. At present, specific effects of the valence and type of cation on SOM properties are incompletely understood. We investigated changes in SOM interfacial properties, its ability to release mobile colloids in aqueous solutions and its sorption affinity towards organic chemicals in dependence on cation–SOM interactions, temperature and aging time. Abstract The present study aims to improve our understanding on the effect of multivalent cations, temperature treatment and isothermal aging time on interfacial soil organic matter (SOM) properties as major factors that modify its supramolecular structures. A sandy topsoil (LW) and a peat soil (SP) were enriched with Na, Ca or Al, or desalinated in a batch experiment, treated at 25, 40, 60 and 105°C and aged at constant temperature and humidity (20°C, 31% relative humidity). After aging for different periods, contact angles (CAs), sorption properties towards xenobiotics and properties of water dispersible colloids were determined. With increasing valence of the dominant cations fewer and larger colloids were observed, probably attributable to cation cross-links or enhanced aggregation caused by reduced surface charge. Al-enrichment of LW resulted in more abundant or more accessible sorption sites for hydrophobic xenobiotics. But in contrast to expectations, hydrophilic sorption as well as wettability was not significantly affected by the type of adsorbed cation. Increasing the temperature had a major effect on surface properties resulting in rising surface hydrophobisation with increasing solid–water CAs, decreasing surface O/C ratio and decreasing sorption of hydrophilic substances; whereas systematic temperature effects on water dispersible colloids and on hydrophobic sorption were not detected. Aging was found to increase the initial CA of the 25°C treatment and to increase the sorption of phenanthrene to LW for all treatment temperatures. We conclude that aging of SOM is a process that changes surface properties and approaches a new equilibrium state after a disturbance. The aging process may be significantly accelerated for samples treated at elevated temperatures.

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Dispersed organic matter characteristics as an indicator of rock alteration degree of the Safyanovskoe copper-sulphide deposit (Middle Urals)

News of the Ural State Mining University ◽

10.21440/2307-2091-2020-1-26-36 ◽

2020 ◽

Vol 1 (1) ◽

pp. 26-36

Author(s):

Elena Industrovna SOROKA ◽

◽

Akhmet Askhatovich GALEEV ◽

Vera Igorevna PETROVA ◽

Vladimir Pavlovich LYUTOEV ◽

...

Keyword(s):

Organic Matter ◽

Elevated Temperatures ◽

Polyaromatic Hydrocarbons ◽

Regional Metamorphism ◽

Epr Spectra ◽

Middle Urals ◽

Geological Processes ◽

Ms Analysis ◽

Siliceous Rocks

Relevance of the study is due to the importance of composition and maturity of the dispersed organic matter (DOM) as indicators of rock forming conditions, which may contribute to the paleoecological reconstruction of sedimentation conditions for rocks in the ore-bearing stratum of the Safyanovskoe deposit. Objective: to analyze the composition and characteristics of DOM in carbon-siliceous rocks of the ore-bearing stratum of the Safyanovsky copper-pyrite deposit. The obtained characteristics of the DOM make it possible to reveal the source of original accumulation and the level of its transformation under the influence of various geological processes. Methods. A detailed study of DOM was carried out by the EPR method (electron paramagnetic resonance) for powder preparations. EPR spectra were recorded at room temperature on X-band spectrometers DX-70, ESR 70-03 DX/2, and SE/X-2547 RadioPAN. The analytical procedure for studying organic matter (OM) included: determination of insoluble residue and C org content in the rock, extraction of the chloroform bitumoids (CB) and the alcohol-benzol bitumoids (ABB), humic acids (HA), determining the group composition of CB and hydrocarbons (HC), chromatographic fractionation with determination of the sum of methane-naphthenic and aromatic fractions of hydrocarbons, GC-MS analysis of n-alkanes, cyclic and polyaromatic hydrocarbons (PAHs). GC-MS analysis was performed on the complex Hewlett Packard 6850/5973 with a quadrupole mass detector and analytical information processing software. Results. Analysis of the EPR spectra of carbon-siliceous rocks of the Safyanovskoe deposit showed the presence of the two types of carbon signal (C-org), characteristic of the plant and the animal residues. It was also found that the DOM has never been exposed to temperatures greater than 300 °C. Geochemical analysis of OM indicates that DOM is at a high maturation stage (residual organic matter (ROM) > 99%). But the type of distribution of polyaromatic hydrocarbons (PAHs) suggests that the primary OM was specifically altered at elevated temperatures. Conclusions. DOM of carbon-siliceous rocks of the Safyanovsky deposit is genetically the same, its type is mainly sapropelic and accumulation is associated with marine conditions. A characteristic feature is, on the one hand, its high polymerization, which is typical for DOM of the stage of late mesocatagenesis, and, on the other hand, its molecular composition does not allow us to talk about the maturation of DOM in the process of natural regional metamorphism.

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Enhanced decomposition offsets enhanced productivity and soil carbon accumulation in coastal wetlands responding to climate change

Biogeosciences Discussions ◽

10.5194/bgd-8-707-2011 ◽

2011 ◽

Vol 8 (1) ◽

pp. 707-722 ◽

Cited By ~ 6

Author(s):

M. L. Kirwan ◽

L. K. Blum

Keyword(s):

Organic Matter ◽

Soil Carbon ◽

Sea Level Rise ◽

Sea Level ◽

Elevated Co2 ◽

Coastal Wetlands ◽

Elevated Temperatures ◽

Carbon Accumulation ◽

Measured Temperature ◽

Elevated Co2 And Temperature

Abstract. Coastal wetlands are responsible for about half of all carbon burial in oceans, and their persistence as a valuable ecosystem depends largely on the ability to accumulate organic material at rates equivalent to relative sea level rise. Recent work suggests that elevated CO2 and temperature warming will increase organic matter productivity and the ability of marshes to survive sea level rise. However, we find that organic decomposition rates increase by about 12% per degree of warming. Our measured temperature sensitivity is similar to studies from terrestrial systems, twice as high as the response of salt marsh productivity to temperature warming, and roughly equivalent to the productivity response associated with elevated CO2 in C3 marsh plants. Therefore, enhanced CO2 and warmer temperatures may actually make marshes less resilient to sea level rise, and tend to promote a release of soil carbon. Simple projections indicate that elevated temperatures will increase rates of sea level rise more than any acceleration in organic matter accumulation, suggesting the possibility of a positive feedback between climate, sea level rise, and carbon emissions in coastal environments.

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