Elevated temperatures drive abiotic and biotic degradation of organic matter in a peat bog under oxic conditions

2022 ◽  
Vol 804 ◽  
pp. 150045
Author(s):  
Roya AminiTabrizi ◽  
Katerina Dontsova ◽  
Nathalia Graf Grachet ◽  
Malak M. Tfaily
Keyword(s):  
Organic Matter ◽  
Elevated Temperatures ◽  
Peat Bog ◽  
Biotic Degradation

scholarly journals Temperature and UV light affect the activity of marine cell-free enzymes

2017 ◽  
Vol 14 (17) ◽  
pp. 3971-3977 ◽  
Author(s):  
Blair Thomson ◽  
Christopher David Hepburn ◽  
Miles Lamare ◽  
Federico Baltar
Keyword(s):  
Organic Matter ◽  
Extracellular Enzymes ◽  
Elevated Temperatures ◽  
Uv Light ◽  
Control Mechanisms ◽  
Potential Control ◽  
Control Factors ◽  
Rate Limiting Step ◽  
Ocean Environment ◽  
First Time

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.

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

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).

scholarly journals Depth Matters in Peat Bog Nutrient Cycling

Eos ◽  
2018 ◽  
Vol 99 ◽  
Author(s):  
David Shultz
Keyword(s):  
Organic Matter ◽  
Nutrient Cycling ◽  
Soil Carbon ◽  
Peat Bog

Peatlands store around a third of Earth’s soil carbon, and a new study begins to reveal how the ecosystems’ organic matter changes with depth.

scholarly journals Assessment of the protective potential of the Moscow region soil cover to contamination with heavy metals and metalloids

2021 ◽  
Vol 27 (4) ◽  
pp. 92-104
Author(s):  
Irina Alyabina ◽  
Olga Chernova ◽  
Vasilisa Kirillova ◽  
Oleg Golozubov ◽  
Sergey Shoba
Keyword(s):  
Heavy Metals ◽  
Organic Matter ◽  
Forest Cover ◽  
Soil Cover ◽  
Moscow Region ◽  
Peat Bog ◽  
Protective Potential ◽  
Podzolic Soils ◽  
Heavy Metals And Metalloids ◽  
Bog Soils

Heavy metals and other trace elements that are not subject to degradation are among the priority pollutants. Significant amounts of heavy metals and related elements with variable valence are deposited on the soil surface as part of aerosols. Accumulating in the soil, they are very slowly removed from it, only changing the level of content or the state during migration, turning the soil over time into a source of secondary pollution. In this regard, an extremely urgent task is to assess the territory, especially such a highly developed and densely populated area as the Moscow Region, in terms of its protective potential to heavy metal pollution. The paper proposes and tested an algorithm for the cartographic assessment of the protective potential of the soil and vegetation cover of the region using GIS analysis methods based on the database “Digital medium-scale soil map of the Moscow region” and a vector map of forest cover. The formula used for calculations includes data on the soil texture, the content of organic matter in soil, the position of the soil in the landscape and the degree of forest cover of the territory. According to the proposed approach, in the Moscow region, the soil cover, taking into account the forest cover, forms 4 groups according to the level of protective potential for contamination with heavy metals and metalloids. The maximum estimate was obtained for noneroded sod-podzolic soils of medium or fine texture, gray forest soils, chernozems and peat bog soils under forest vegetation (17 % of the area). Unerroded soddy-podzolic soils of varying degrees of podzolization and gleying (45 %) received an average rating. Even lower is the protective potential of 22 % of the territory represented by eroded gray forest soils, various sod-podzolic, alluvial and peat bog soils. This group is the most heterogeneous in terms of soil texture, organic matter content and degree of forest cover. The group with a minimum protective potential included eroded soils, soils of gully-girder complexes, sod-podzolic soils of coarst texture, as well as alluvial peat and peaty soils (about 16 %).

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

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.

Introduction

2021 ◽  
pp. 1-20
Author(s):  
David Rickard
Keyword(s):  
Organic Matter ◽  
High Temperature ◽  
Water Column ◽  
Peat Bog ◽  
Chemical Analyses ◽  
Limited Distribution ◽  
Sulfate Reducing ◽  
Technological Advances ◽  
Framboid Formation ◽  
Reducing Bacteria

Framboids are microscopic subspherical clusters of equant and equidimensional microcrystals. They overwhelmingly consist of the mineral pyrite, cubic FeS2. There are about 1030 framboids on Earth and they are forming at a rate of about 1014 per second. They may be the most abundant mineral texture on Earth. Framboids are especially concentrated in sediments, although they are also to be found in the water column and in high temperature systems. The oldest framboids are possibly 2.9 Ga and they are found in all geologic periods from that time. The first framboids were described in 1885 from a peat bog, and the term framboid was coined in 1935. They have fascinated researchers ever since, not least because a substantial fraction of them display astonishing regular microarchitectures where their constituent microcrystals are geometrically ordered. Understanding of the nature of framboids has paralleled technological advances in microscopy, structural and chemical analyses, and computing. The sulfur in sedimentary framboids is almost exclusively sourced from sulfate-reducing bacteria, and the idea that framboids were fossil microorganisms was first propounded in 1923. Subsequently, the limited distribution of organic matter in framboids, its absence in hydrothermal framboids, and inorganic framboid syntheses showed that organisms were not necessary for framboid formation.

scholarly journals Pedochronology and development of peat bog in the environmental protection area pau-de-fruta - Diamantina, Brazil

2010 ◽  
Vol 34 (6) ◽  
pp. 1965-1975 ◽  
Author(s):  
José Ricardo da Rocha Campos ◽  
Alexandre Christófaro Silva ◽  
Leandro Lara Vasconcellos ◽  
Daniel Valladão Silva ◽  
Rafael Vitor Romão ◽  
...  
Keyword(s):  
Organic Matter ◽  
Environmental Protection ◽  
Isotope Analysis ◽  
Chemical Properties ◽  
Peat Bog ◽  
Radiocarbon Age ◽  
Environmental Protection Area ◽  
Protection Area ◽  
Organic Matter Fractions ◽  
Microbiological Analyses

In the region of the Serra do Espinhaço Meridional, peat bog is formed in hydromorphic environments developed in sunken areas on the plain surfaces with vegetation adapted to hydromorphic conditions, favoring the accumulation and preservation of organic matter. This pedoenvironment is developed on the regionally predominant quartzite rocks. Peat bog in the Environmental Protection Area - APA Pau-de-Fruta, located in the watershed of Córrego das Pedras, Diamantina,Brazil, was mapped and three representative profiles were morphologically characterized and sampled for physical, chemical and microbiological analyses. The organic matter was fractionated into fulvic acid (FA), humic acids (HA) and humin (H). Two profiles were sampled to determine the radiocarbon age and δ13C. The structural organization of the three profiles is homogeneous. The first two layers consist of fibric, the two subsequent of hemic and the four deepest of sapric peat, showing that organic matter decomposition advances with depth and that the influence of mineral materials in deeper layers is greater. Physical properties were homogeneous in the profiles, but varied in the sampled layers. Chemical properties were similar in the layers, but the Ca content, sum of bases and base saturation differed between profiles. Contents of H predominated in the more soluble organic matter fractions and were accumulated at a higher rate in the surface and deeper layers, while HA levels were higher in the intermediate and FA in the deeper layers. Microbial activity did not vary among profiles and was highest in the surface layers, decreasing with depth. From the results of radiocarbon dating and isotope analysis, it was inferred that bog formation began about 20 thousand years ago and that the vegetation of the area had not changed significantly since then.

The role of mineralization of the organic matter of soddy-podzolic and peat bog soils in the accumulation of 137Cs by plants

2010 ◽  
Vol 43 (10) ◽  
pp. 1109-1119 ◽  
Author(s):  
A. S. Tulina ◽  
V. M. Semenov ◽  
N. N. Tsybul’ka ◽  
T. P. Shapsheeva ◽  
A. A. Zaitsev ◽  
...  
Keyword(s):  
Organic Matter ◽  
Peat Bog ◽  
Bog Soils

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

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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