Bacterial Mineralization of Organic Carbon Under Anaerobic Conditions

2021 ◽  
pp. 219-247
Author(s):  
Henry L. Ehrlich
Keyword(s):  
Organic Carbon ◽  
Anaerobic Conditions

The Influence of Nitrogen on Phosphorus Removal in Activated Sludge Plants

1982 ◽  
Vol 14 (1-2) ◽  
pp. 31-45 ◽  
Author(s):  
J L Barnard
Keyword(s):  
Organic Carbon ◽  
Activated Sludge ◽  
Phosphorus Removal ◽  
Complete Removal ◽  
Phosphate Removal ◽  
Electron Donors ◽  
Biological Phosphorus Removal ◽  
Anaerobic Conditions ◽  
Low Level ◽  
Biological Phosphorus

This paper discusses the need for anaerobiases as a pre-requisite for phosphorus removal in activated sludge plants and the effect of nitrates on the anaerobic conditions. If the plant could be operated to avoid nitrification, biological phosphorus removal presents no problems. When nitrification is required, the nitrates must be reduced to a low level through internal denitrification. If sufficient carbon is available to ensure complete removal of the nitrates and anaerobic conditions in a specific zone in the plant, good phosphate removal can be ensured. Below COD : TKN ratios of 10 : 1 it is becoming more difficult to control the plant and special care should be taken to determine not only the quantity of organic carbon available as electron donors for removal of the nitrates but also the form in which it arrives at the plant.

scholarly journals Effects of detritus chemical composition on the anaerobic mineralization of Salvinia auriculata and Utricularia breviscapa

2015 ◽  
Vol 27 (2) ◽  
pp. 202-212
Author(s):  
Marcela Bianchessi da Cunha Santino ◽  
Irineu Bianchini Júnior
Keyword(s):  
Organic Carbon ◽  
Anaerobic Degradation ◽  
Aquatic Macrophytes ◽  
Life Forms ◽  
Mass Balances ◽  
Anaerobic Conditions ◽  
Gas Formation ◽  
Set Up ◽  
Loss Experiment ◽  
Carbon Particulate

Aim: This study was conducted to evaluate the effect of the detritus composition on the anaerobic mineralization of two species of aquatic macrophytes with different life forms (submerged and free floating). The hypothesis that guided this study was that the carbon concentration derived from detritus hydrosoluble fraction can act as a facilitating factor on its degradation.Material and MethodsIncubations containing detritus and water sample from the Óleo Lagoon (21° 33’ to 21° 37’ S and 47° to 47° 45’ to 51’ W) for each specie (Salvinia auriculata and Utricularia breviscapa) were set-up with: (i) integral detritus (sample of dried plant), (ii) lignocellulosic matrix (particulate organic matter (POM) remaining from leachate extraction) and (iii) leachate. The incubations were kept in the dark under anaerobic conditions. Daily rates of gas formation were evaluated and after 138 days, the incubations were fractioned in dissolved and particulate fractions and the mass balances were performed. A mass loss experiment (180 days) was performed for assessment of the dissolved organic carbon, particulate organic carbon and mineralized carbon variations.ResultsRegardless of the type of detritus (S. auriculata and U. breviscapa), C-mineralization was faster and higher in the DOC incubations (ca. 85%). For U. breviscapa the POM mineralization was slower than the corresponding integral detritus and S. auriculata mineralization was slower than U. breviscapa.ConclusionsThe composition of the detritus (i.e. macrophyte type, presence and proportion of leachate) interfered synergistically in anaerobic degradation of these plants. The leachate tends to act as a facilitator, supporting the growth of microorganisms and intensifying mineralization.

The sorption and degradation of the rice pesticides fipronil and thiobencarb on two Australian rice soils

Soil Research ◽  
2006 ◽  
Vol 44 (6) ◽  
pp. 599 ◽  
Author(s):  
Gregory Doran ◽  
Philip Eberbach ◽  
Stuart Helliwell
Keyword(s):  
Organic Carbon ◽  
Absolute Amount ◽  
Anaerobic Conditions ◽  
Rice Soils ◽  
Aerobic Conditions ◽  
Soil Microbial ◽  
Layer Analysis ◽  
Lag Period ◽  
The Difference ◽  
Soil Microbial Population

The sorption and degradation of the rice pesticides fipronil and thiobencarb on 2 Australian rice-growing soils were investigated. Greater sorption of both pesticides occurred on the soil containing less organic carbon, possibly as a result of the type of organic carbon present, rather than the absolute amount. While sorption tended to appear greater in the 0–10 mm layer than the 10–20 mm layer, analysis showed the difference was not significant (P > 0.05). Under aerobic conditions, a lag period of 20 days in the degradation of thiobencarb occurred on the Yanco soil, but rapid degradation occurred on the Coleambally soil, and, while unlikely, may have been a consequence of preconditioning of the Coleambally soil microbial population. Degradation of thiobencarb under both non-flooded anaerobic and flooded anaerobic conditions differed significantly (P < 0.05) compared to aerobic conditions. Conversely, fipronil degraded rapidly over the first few days and then slowed, and was attributed to the co-metabolism of fipronil by soil microbes. While fipronil sulfide was produced under all oxic/anoxic conditions, its concentration was greatest under flooded anaerobic conditions, possibly as a result of greater exclusion of oxygen from the soil by the floodwater.

Prediction of organic matter degradability in river sediments

2020 ◽  
Author(s):  
Julia Gebert ◽  
Florian Zander
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Spatial Variability ◽  
River Sediments ◽  
Redox Conditions ◽  
Time Dependent ◽  
Anaerobic Conditions ◽  
Short Term ◽  
Aerobic And Anaerobic

&lt;p&gt;Under anaerobic conditions, degradation of organic matter in river sediments leads to gas formation, with organic carbon being released mainly as CH&lt;sub&gt;4&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt;. Gas bubbles reduce sediment density, viscosity and shear strength, impede sonic depth finding and are suspected to affect the sediments&amp;#8217; rheological properties. Moreover, methane (CH&lt;sub&gt;4&lt;/sub&gt;) is a potent greenhouse gas with a global warming potential (GWP&lt;sub&gt;100&lt;/sub&gt;) of 28-36. Therefore, the climate impact may vary greatly depending on the way sediments are managed (for example, type and frequency of dredging and relocation in the water body or treatment on land). The objective of this paper is therefore to quantify the time-dependent stability, or inversely, the lability of sediment organic matter (SOM) as a basis for prediction of effects on sediment mechanical properties and on the release of greenhouse gases.&lt;/p&gt;&lt;p&gt;Within two years, over 200 samples of predominantly fine-grained sediment were collected from nine locations within a 30 km transect through the Port of Hamburg. All samples were, amongst other analyses, subjected to long-term (&gt; 250 days) aerobic and anaerobic incubation for measurement of SOM degradation, yielding a comprehensive data set on the time-dependent change in degradation rates and the corresponding size of differently degradable SOM pools. SOM degradability exhibited a pronounced spatial variability with an approximately tenfold higher anaerobic and a roughly fivefold higher aerobic degradability of upstream SOM compared to downstream SOM. Lower &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C values, higher DNA concentrations and a higher share of organic carbon in the light density fraction as well as elevated chlorophyll concentrations in the water phase support the hypothesis of increased biological sources of SOM at upstream locations and increased SOM degradability in shallow compared to deep layers (Zander et al., 2020).&lt;/p&gt;&lt;p&gt;First statistical and time series analyses indicate that&lt;/p&gt;&lt;ul&gt;&lt;li&gt;Long-term SOM lability appears to be predictable from short-term measurements.&lt;/li&gt; &lt;li&gt;The relationship between short-term and long-term SOM degradation is site-specific and also differs for layers of different age (depth). This supports the above-mentioned variability between sites regarding the size of differently degradable carbon pools, as well as for the depth profile at any one site.&lt;/li&gt; &lt;li&gt;The relevance of the available electron acceptors (redox conditions) for SOM degradation, i.e. the ratio between carbon release under aerobic and anaerobic conditions, differs less by site but more so by layers of different age (depth). This is plausible as especially the top layers are exposed to more variability in redox conditions than the deeper layers that are always under reducing conditions.&lt;/li&gt; &lt;/ul&gt;&lt;p&gt;Zander, F., Heimovaara, T., Gebert, J. (2020): Spatial variability of organic matter degradability in tidal Elbe sediments. Journal of Soils and Sediments, accepted for publication.&lt;/p&gt;

The Response of the Microbial Community of Marine Sediments to Organic Carbon Input under Anaerobic Conditions

1999 ◽  
Vol 22 (2) ◽  
pp. 237-248 ◽  
Author(s):  
Ramon Rosselló-Mora ◽  
Bo Thamdrup ◽  
Hendrik Schäfer ◽  
Roland Weller ◽  
Rudolf Amann
Keyword(s):  
Microbial Community ◽  
Organic Carbon ◽  
Marine Sediments ◽  
Anaerobic Conditions

Nitrification in a Vertisol subsoil and its relationship to the accumulation of ammonium-nitrogen at depth

Soil Research ◽  
2002 ◽  
Vol 40 (5) ◽  
pp. 727 ◽  
Author(s):  
K. L. Page ◽  
W. M. Strong ◽  
R. C. Dalal ◽  
N. W. Menzies
Keyword(s):  
Organic Carbon ◽  
Environmental Conditions ◽  
Soil Analysis ◽  
Field Studies ◽  
Ammonium Nitrogen ◽  
Carbon Substrate ◽  
Anaerobic Conditions ◽  
Incubation Study ◽  
High Concentrations ◽  
Low Rate

Unusually high concentrations of ammonium have been observed in a Vertisol below 1 m depth in south-east Queensland. This study investigated the possibility that an absence of nitrification is allowing this ammonium to accumulate and persist over time, and examined the soil environmental characteristics that may be responsible for limiting nitrifying organisms. The possibility that anaerobiosis, soil acidity, soil salinity, low organic carbon concentrations, and/or an absence of active nitrifying microorganisms were responsible for limiting nitrification was examined in laboratory and field studies. The presence/absence of anaerobic conditions was determined qualitatively using a field test to give an indication of electron lability. In addition, an incubation study was conducted and soil environmental conditions were improved for nitrifying organisms by adjusting the pH from 4.4 to 7, adjusting the electrical conductivity from 1.6 to 0.5 dS/m, amending with a soluble carbon substrate at a rate of 500 mg/kg, and using microorganisms from the surface horizon to inoculate to the subsoil. Over a 180-day period no nitrification was detected in the control samples from the incubation study, indicating that an extremely low rate of nitrification is likely to be responsible for allowing ammonium to accumulate in this soil. Analysis of the effect of soil environmental conditions on nitrification revealed that anaerobic conditions did not exist at depth and that pH, EC, organic carbon, and inoculation treatments added in isolation had no effect on nitrification. However, when inoculum was added to the soil in combination with pH, a significant increase in nitrification was observed, and the greatest amount of nitrification was observed when inoculum, pH, and EC treatments were added in combination. It was concluded that the reason for the low rate of nitrification in this soil is primarily the absence of a significant population of active nitrifying microorganisms, which may have been unable to colonise the subsoil environment due to its acidic, and to a lesser extent, its saline environment.

scholarly journals Aerobic and anaerobic degradation of tannic acid on water samples from Monjolinho reservoir (São Paulo, SP, Brazil)

2002 ◽  
Vol 62 (4a) ◽  
pp. 585-590 ◽  
Author(s):  
M. B. CUNHA-SANTINO ◽  
I. BIANCHINI Jr. ◽  
L. E. F. SERRANO
Keyword(s):  
Organic Carbon ◽  
Tannic Acid ◽  
Anaerobic Degradation ◽  
High Capacity ◽  
Order Kinetic ◽  
Anaerobic Conditions ◽  
First Order ◽  
Order Kinetic Model ◽  
Carbon Concentrations ◽  
Aerobic And Anaerobic

In order to describe the transformations of tannic acid during its degradation (under aerobic and anaerobic conditions) incubations were performed. To evaluate the oxygen consumption, the tannic acid was added to 1 L of water sample from Monjolinho's reservoir (22º00'S and 47º54'W); these solutions were aerated and the dissolved oxygen was monitored for 16 days, the anaerobic process was avoided. For the anaerobic and aerobic degradation, the dissolved organic carbon and the acid tannic concentrations were estimated on the samples days. The results were fitted to first-order kinetic model, being possible to verify that during the 16 days the oxygen uptake was 3.6 mg.L-1, the deoxygenation rate (kD)of this process was 0.39 day-1. The degradation coefficients were calculated through the decay of the tannic acid and organic carbon concentrations. In the aerobic process, the global decay coefficient (kG) was 0.36 day-1 and in the anaerobic 0.28 day-1. Overall, the obtained degradation coefficients suggest that the bacterioplankton of the Monjolinho's reservoir possess a high capacity of polyphenols degradation.

scholarly journals Molecular characterization of organic matter mobilized from Bangladeshi aquifer sediment: tracking carbon compositional change during microbial utilization

2017 ◽  
Author(s):  
Lara E. Pracht ◽  
Malak M. Tfaily ◽  
Robert J. Ardissono ◽  
Rebecca B. Neumann
Keyword(s):  
Organic Carbon ◽  
High Resolution Mass Spectrometry ◽  
Sandy Sediment ◽  
Organosulfur Compounds ◽  
Aquifer Recharge ◽  
Anaerobic Conditions ◽  
Microbial Utilization ◽  
Microbial Sulfate Reduction ◽  
Sedimentary Organic Carbon

Abstract. Bioavailable organic carbon in aquifer-recharge waters and sediments can fuel microbial reactions with implications for groundwater quality. A previous incubation experiment showed that sedimentary organic carbon (SOC) mobilized off sandy sediment collected from an arsenic-contaminated and methanogenic aquifer in Bangladesh was bioavailable; it was fermented into methane. We used high-resolution mass spectrometry to molecularly characterize this mobilized SOC, reference its composition against dissolved organic carbon (DOC) in aquifer recharge water, track compositional changes during incubation, and advance understanding of how composition relates to bioavailability in anaerobic conditions. Mobilized SOC was more diverse and proportionately larger, more aromatic and more oxidized than DOC in surface recharge. In all samples, ~ 50 % of identified compounds contained sulfur. After SOC was fermented into methane, new organosulfur compounds with high S-to-C ratios and high nominal oxidation state of carbon (NOSC) were detected. We conjecture these detected compounds were microbially synthesized to biochemically support methane production or they formed abiotically following microbial sulfate reduction, which could have occurred during incubation but was not directly measured. Microbes transformed all carbon types during incubation, including those considered molecularly recalcitrant (e.g., condensed aromatics) and thermodynamically unfavourable to oxidize (e.g., low NOSC). While all compound types were eventually degraded, NOSC and compound size controlled the rates of carbon transformation. Large energy-rich compounds (e.g., aromatics with high NOSC) were targeted first while small energy-poor compounds (e.g., alkanes and olefinics with low NOSC) persisted. Preferential use of aromatic compounds, which are typically considered molecularly recalcitrant, demonstrates that in the anaerobic conditions of the incubation, thermodynamic favourability of carbon oxidation rather than molecular structure controlled the rate of carbon degradation by microbes.

scholarly journals Anaerobic Oxidation of Arsenite Linked to Chlorate Reduction

2010 ◽  
Vol 76 (20) ◽  
pp. 6804-6811 ◽  
Author(s):  
Wenjie Sun ◽  
Reyes Sierra-Alvarez ◽  
Lily Milner ◽  
Jim A. Field
Keyword(s):  
Organic Carbon ◽  
16S Rrna ◽  
Molar Ratio ◽  
Gene Clone ◽  
Rrna Gene ◽  
Microbial Oxidation ◽  
Anaerobic Conditions ◽  
Low Concentrations ◽  
Pure Cultures ◽  
Low Levels

ABSTRACT Microorganisms play a significant role in the speciation and mobility of arsenic in the environment. In this study, the oxidation of arsenite [As(III)] to arsenate [As(V)] linked to chlorate (ClO3 −) reduction was shown to be catalyzed by sludge samples, enrichment cultures (ECs), and pure cultures incubated under anaerobic conditions. No activity was observed in treatments lacking inoculum or with heat-killed sludge, or in controls lacking ClO3 −. The As(III) oxidation was linked to the complete reduction of ClO3 − to Cl−, and the molar ratio of As(V) formed to ClO3 − consumed approached the theoretical value of 3:1 assuming the e − equivalents from As(III) were used to completely reduce ClO3 −. In keeping with O2 as a putative intermediate of ClO3 − reduction, the ECs could also oxidize As(III) to As(V) with O2 at low concentrations. Low levels of organic carbon were essential in heterotrophic ECs but not in autotrophic ECs. 16S rRNA gene clone libraries indicated that the ECs were dominated by clones of Rhodocyclaceae (including Dechloromonas, Azospira, and Azonexus phylotypes) and Stenotrophomonas under autotrophic conditions. Additional phylotypes (Alicycliphilus, Agrobacterium, and Pseudoxanthomonas) were identified in heterotrophic ECs. Two isolated autotrophic pure cultures, Dechloromonas sp. strain ECC1-pb1 and Azospira sp. strain ECC1-pb2, were able to grow by linking the oxidation of As(III) to As(V) with the reduction of ClO3 −. The presence of the arsenite oxidase subunit A (aroA) gene was demonstrated with PCR in the ECs and pure cultures. This study demonstrates that ClO3 − is an alternative electron acceptor to support the microbial oxidation of As(III).

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