scholarly journals Source and quantity of carbon influence its sequestration in Rostherne Mere (UK) sediment: a novel application of stepped combustion radiocarbon analysis

2020 ◽  
Vol 64 (4) ◽  
pp. 347-363
Author(s):  
Evelyn M. Keaveney ◽  
Alan D. Radbourne ◽  
Suzanne McGowan ◽  
David B. Ryves ◽  
Paula J. Reimer
Keyword(s):  
Carbon Source ◽  
Organic Carbon ◽  
Accumulation Rate ◽  
Carbon Sources ◽  
Carbon Accumulation ◽  
Phytoplankton Production ◽  
Catchment Management ◽  
Sediment Organic Carbon ◽  
Rostherne Mere ◽  
Recalcitrant Carbon

Abstract We explored the roles of phytoplankton production, carbon source, and human activity on carbon accumulation in a eutrophic lake (Rostherne Mere, UK) to understand how changes in nutrient loading, algal community structure and catchment management can influence carbon sequestration in lake sediments. Water samples (dissolved inorganic, organic and particulate carbon) were analysed to investigate contemporary carbon sources. Multiple variables in a 55-cm sediment core, which represents the last ~ 90 years of accumulation, were studied to determine historical production rates of algal communities and carbon sources. Fluctuations in net primary production, inferred from sedimentary diatom abundance and high-performance liquid chromatography (HPLC) pigment methods, were linked to nutrient input from sewage treatment works (STW) in the catchment. Stepped combustion radiocarbon (SCR) measurements established that lake sediment contains between 11% (~ 1929 CE) and 69% (~ 1978 CE) recalcitrant carbon, with changes in carbon character coinciding with peaks in accumulation rate and linked to STW inputs. Catchment disturbance was identified by radiocarbon analysis, and included STW construction in the 1930s, determined using SCR analysis, and recent nearby highway construction, determined by measurements on dissolved organic carbon from the lake and outflow river. The quantity of autochthonous carbon buried was related to diatom biovolume accumulation rate (DBAR) and decreased when diatom accumulation rate and valve size declined, despite an overall increase in net carbon production. HPLC pigment analysis indicated that changes in total C deposition and diatom accumulation were related to proliferation of non-siliceous algae. HPLC results also indicated that dominance of recalcitrant carbon in sediment organic carbon was likely caused by increased deposition rather than preservation factors. The total algal accumulation rate controlled the sediment organic carbon accumulation rate, whereas DBAR was correlated to the proportion of each carbon source buried.

scholarly journals Bacterial carbon sources in coastal sediments: a cross-system analysis based on stable isotope data of biomarkers

2006 ◽  
Vol 3 (2) ◽  
pp. 175-185 ◽  
Author(s):  
S. Bouillon ◽  
H. T. S. Boschker
Keyword(s):  
Fatty Acids ◽  
Organic Carbon ◽  
Salt Marshes ◽  
System Analysis ◽  
Carbon Sources ◽  
Isotopic Fractionation ◽  
Coastal Sediments ◽  
Large Variability ◽  
Coastal Systems ◽  
Sediment Organic Carbon

Abstract. Coastal ecosystems are typically highly productive, and the sediments in these systems receive organic matter from a variety of local and imported sources. To assess if general patterns are present in the origin of carbon sources for sedimentary bacteria and their relation to the origin of the sediment organic carbon pool, we compiled both literature and new data on δ13C of bacterial biomarkers (the phospholipid derived fatty acids i+a15:0), along with δ13C data on sediment organic carbon (δ13CTOC) and macrophyte biomass from a variety of typical near-coastal systems. These systems included mangroves, salt marshes (both C3 and C4-dominated sites), seagrass beds, and macroalgae-based systems, as well as unvegetated sediments. First, our δ13Ci+a15:0 data showed large variability over the entire range of δ13CTOC, indicating that in many settings, bacteria may depend on carbon derived from various origins. Secondly, systems where local macrophyte production is the major supplier of organic carbon for in situ decomposition are generally limited to organic carbon-rich, peaty sites (TOC>10 wt%), which are likely to make up only a small part of the global area of vegetated coastal systems. These carbon-rich sediments also provided a field based estimate of isotopic fractionation between bacterial carbon sources and biomarkers (-3.7±2.1), which is similar to the expected value of about -3 associated with the biosynthesis of fatty acids. Thirdly, only in systems with low TOC (below ~1 wt%), we consistently found that bacteria were selectively utilizing an isotopically enriched carbon source, which may be root exudates but more likely is derived from microphytobenthos. In other systems with between ~1 and 10 wt% TOC, bacteria appear to show on average little selectivity and δ13Ci+a15:0 data generally follow the δ13CTOC, even in systems where the TOC is a mixture of algal and macrophyte sources that generally are believed to have a very different degradability.

scholarly journals Dissolved organic carbon vertical movement and carbon accumulation in West Siberian peatlands

2021 ◽  
Author(s):  
Evgeny A. Zarov ◽  
Elena D. Lapshina ◽  
Iris Kuhlmann ◽  
Ernst-Detlef Schulze
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Accumulation Rate ◽  
Bottom Layer ◽  
Vertical Movement ◽  
Carbon Accumulation ◽  
Downward Movement ◽  
Average Value ◽  
Lack Of Information ◽  
Lake Bottom

Abstract. Dissolved organic carbon is an additional path of carbon cycle but there is a lack of information about its distribution in peatland and rates of downward movement. We dated seven peat cores (separately the dissolved (DOC) and particulate (POC) organic carbon) from Mukhrino peatland (typical zonal oligotrophic bog) in western Siberia to assess the date distribution between those two peat fractions. Our results revealed that the DOC is younger than POC for the surface peatland layers (0–150 cm) and older for the deeper layers. The date differences increases with depth and reaches 2000–3000 years at the bottom layer (430–530 cm). In our hypothesis this date discrepancy caused by more young DOC moving to the deeper and older peat layers. The estimated average value of DOC downward movement was 0.047 ± 0.019 cm yr−1. Th oldest dates found at the lake bottom and ancient riverbed were 10 053 and 10 989 cal yr BP correspondingly. For the whole period of peatland functioning the average peat accumulation rate was estimated as 0.067 ± 0.018 cm yr−1 (0.013–0.332 cm yr−1), the carbon accumulation rate was estimated as 38.56 ± 12.21 g С m−2 yr−1 (28.46–57.91 g С m−2 yr−1).

Implications of Peat Accumulation at Point Escuminac, New Brunswick

1993 ◽  
Vol 39 (2) ◽  
pp. 245-248 ◽  
Author(s):  
Barry G. Warner ◽  
Richard S. Clymo ◽  
Kimmo Tolonen
Keyword(s):  
Organic Carbon ◽  
New Brunswick ◽  
Positive Feedback ◽  
Carbon Sources ◽  
Carbon Accumulation ◽  
Lower Zone ◽  
True Rate ◽  
Peat Accumulation ◽  
Warming Climate ◽  
Selective Decay

AbstractThe world's peatlands contain about 450 GT of readily decomposeable organic carbon. Peat-forming systems have two main layers, of which the lowest is the thickest and includes the peat proper. The upper layer fixes carbon by photosynthesis, loses it by selective decay, and passes on about 15% to the lower zone; here decay continues, although very slowly. One consequence is that as for Point Escuminac, New Brunswick, the relation of age to depth may be concave. Although the surface of the peatland is as productive as ever, the true rate of carbon accumulation is decreasing; after 10,000 yr it is only 33% as efficient at sequestering carbon as it was when the peatland began to grow. Peatlands are usually thought to represent sinks for carbon, but a warming climate could make some peatlands carbon sources rather than sinks, thus initiating positive feedback.

Effects of Solid Organic Carbon on Nitrate Remove in Groundwater

2014 ◽  
Vol 955-959 ◽  
pp. 2285-2289
Author(s):  
Yun Xiao Jin ◽  
Hai Mei Fu
Keyword(s):  
Carbon Source ◽  
Organic Carbon ◽  
Carbon Sources ◽  
Nitrogen Compounds ◽  
Filling Material ◽  
Solid Carbon ◽  
Solid Carbon Source ◽  
Source Materials ◽  
Potential Carbon

In groundwater, the lack of carbon source is a key problem of in-situ denitrification. It is very important to choose appropriate solid carbon-source materials. In this work, wheatstraw and sawdust were selected as potential carbon sources to evaluate the performance for in-situ biological denitrification in groundwater by column experiments. The results showed that sawdust was a suitable corbon source with less release of nitrogen compounds and relatively stable release of organic carbon, compared with wheatstraw, and was applicable for further use as a filling material in in-situ ground water bioremediation.

scholarly journals Spatial and temporal organic carbon burial along a fjord to coast transect: A case study from Western Norway

The Holocene ◽  
2017 ◽  
Vol 27 (9) ◽  
pp. 1325-1339 ◽  
Author(s):  
CJ Duffield ◽  
E Alve ◽  
N Andersen ◽  
TJ Andersen ◽  
S Hess ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Carbon Isotopes ◽  
Accumulation Rate ◽  
Carbon Accumulation ◽  
Individual Species ◽  
Accumulation Rates ◽  
Foraminiferal Assemblage ◽  
Assemblage Composition ◽  
Western Norway ◽  
Carbon Accumulation Rates

We investigated spatial and temporal changes in accumulation rate and source of organic carbon on a gradient along the Lysefjord and the more coastal Høgsfjord, Western Norway. This was achieved through analysis of total organic carbon and nitrogen content of sediment cores, which were radiometrically dated to the early 19th and 20th centuries for the Høgsfjord and Lysefjord, respectively. Benthic foraminifera (protists) were utilized to determine changes in organic carbon supply and Ecological Quality Status (EcoQS) by their accumulation rate (benthic foraminiferal accumulation rate (BFAR)), assemblage composition, species diversity, individual species responses and the composition of stable carbon isotopes of the tests (shells) of Cassidulina laevigata, Hyalinea balthica and Melonis barleeanus. Organic carbon accumulation rates were greatest closest to the river Lyse at the head of the Lysefjord (83–171 g C m−2 yr−1). The organic carbon at the head of the fjord is mainly terrestrial in origin, and this terrestrial influence becomes progressively less seaward. The δ13C in H. balthica tests as well as the benthic foraminiferal assemblage composition also showed a clear fjord to coast gradient. Organic carbon accumulation rates were lower and less variable at the seaward study sites (13–61 g C m−2 yr−1). We observe no temporal trend in organic carbon, carbon isotopes, EcoQS or foraminiferal assemblage composition in the Lysefjord. In contrast, in the Høgsfjord, there seems to have been an increase in organic carbon accumulation rates during the 1940s. Subsequent accumulation rates are stable. The foraminiferal assemblages in the surface sediments reflect a recent transition from good/moderate to moderate/bad EcoQS.

Effect on the Characteristic and Properties of Carbon Coated LiFePO4/C Composite

2011 ◽  
Vol 689 ◽  
pp. 367-371
Author(s):  
Yu Li Zhang ◽  
Zhi Jian Liu ◽  
Jian Hua Xia ◽  
Xi Lin ◽  
Lu Xing Chen
Keyword(s):  
Carbon Source ◽  
Organic Carbon ◽  
Carbon Sources ◽  
Thermal Reduction ◽  
Reduction Technique ◽  
High Rate ◽  
Tap Density ◽  
Organic Carbon Sources ◽  
Different Types ◽  
Carbon Coated

LiFePO4/C composite with different types of organic carbon sources has been synthesized by carbon thermal reduction technique. The physical characteristics and electrochemical properties of LiFePO4/C composite have been studied compared with commercial products. It is shown that good carbon-coated LiFePO4/C composite can be obtained with 13wt.% glucose as carbon source, which has effected on the good processing performance due to its suitable specific surface area of 26.3m2/g and high tap density of 1.3g/cm3. Furthermore, it has contributed to the high-rate electrochemical property with discharge capacity of 128mAh/g at 1C (1C=170 mAh/g).

Organic carbon effect on nitrifying bacteria in a mixed culture

2010 ◽  
Vol 61 (11) ◽  
pp. 2951-2956 ◽  
Author(s):  
L. Racz ◽  
T. Datta ◽  
R. K. Goel
Keyword(s):  
Carbon Source ◽  
Organic Carbon ◽  
Sodium Acetate ◽  
Carbon Sources ◽  
Cod Removal ◽  
Nitrifying Bacteria ◽  
Batch Reactors ◽  
Ammonia Oxidizing Bacteria ◽  
Sequencing Batch Reactors ◽  
Organic Carbon Source

This study investigated the effect of organic carbon source on ammonia oxidizing community in single sludge laboratory scale sequencing batch reactors (SBR). Two sequencing batch reactors performing simultaneous carbon oxidation and nitrification were operated. Operationally and functionally, these two reactors were identical, except that one reactor was fed peptone and sodium acetate, and the other was fed glucose and sodium acetate as external organic carbon sources. The peptone-fed reactor had 98.1±1.84% COD removal and 97.3±6.69% NH3-N oxidation. The glucose-fed reactor had 99.1±1.29% COD removal and 99.4±0.76% NH3-N oxidation. The reactor fed with peptone, a complex organic carbon source comprised of enzymatic digests of animal proteins, had greater diversity in both the heterotrophic bacterial community and the ammonia oxidizing bacteria community than in the reactor fed with glucose, a simple sugar as evidenced by automated ribosomal intergenic spacer analysis (ARISA) and terminal restriction fragment length polymorphism (TRFLP) experiments respectively.

The rate of iron corrosion for different organic carbon sources during biofilm formation

2007 ◽  
Vol 55 (8-9) ◽  
pp. 489-497 ◽  
Author(s):  
S.-K. Park ◽  
S.-C. Choi ◽  
Y.-K. Kim
Keyword(s):  
Carbon Source ◽  
Organic Carbon ◽  
Corrosion Rate ◽  
Humic Substances ◽  
Carbon Sources ◽  
Biofilm Reactor ◽  
Major Constituent ◽  
Iron Corrosion ◽  
Organic Carbon Sources ◽  
Biofilm Bacteria

The effects of total organic carbon and biofilm on microbial corrosion were quantified using serum bottles in a 2×2 factorial design. Both organic carbon and biofilm bacteria had a significant effect on the iron corrosion rate, irrespective of the levels of the other variable (p=0.05). There was no evidence of interaction between organic carbon and biofilm bacteria. Within the tested levels, the addition of exogenous organic carbon increased the corrosion rate by an average of 3.838 mg dm−2 day−1 (mdd), but the presence of biofilm bacteria decreased the rate by an average of 2.305 mdd. More iron was released from the coupon in response to organic carbon. Powder x-ray diffractometry indicated that the scales deposited on the corroded iron surface consisted primarily of lepidocrocite (γ-FeOOH), magnetite (Fe3O4) and hematite (α-Fe2O3). Corrosion rates by different organic carbon sources, i.e. acetate, glucose and humic substances, were compared using an annular biofilm reactor. One-way ANOVA suggested that the effect of each carbon source on corrosion was not the same, with the iron corrosion rate highest for glucose, followed by acetate, humic substances and the control. Magnetite was a major constituent of the corrosion products scraped from iron slides. Examination of community-level physiological profile patterns on the biofilms indicated that acetate was a carbon source that could promote the metabolic and functional potentials of biofilm communities.

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