scholarly journals Halogens in pore water of peat bogs – the role of peat decomposition and dissolved organic matter

2006 ◽  
Vol 3 (1) ◽  
pp. 53-64 ◽  
Author(s):  
H. Biester ◽  
D. Selimović ◽  
S. Hemmerich ◽  
M. Petri
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Pore Water ◽  
Peat Bogs ◽  
Pore Waters ◽  
Peat Pore Water ◽  
Icp Ms ◽  
Halogen Species

Abstract. Halogens are strongly enriched in peat and peatlands and such they are one of their largest active terrestrial reservoir. The enrichment of halogens in peat is mainly attributed to the formation of organohalogens and climatically controlled humification processes. However, little is known about release of halogens from the peat substrate and the distribution of halogens in the peat pore water. In this study we have investigated the distribution of chlorine, bromine and iodine in pore water of three pristine peat bogs located in the Magellanic Moorlands, southern Chile. Peat pore waters were collected using a sipping technique, which allows in situ sampling down to a depth greater than 6m. Halogens and halogen species in pore water were determined by ion-chromatography (IC) (chlorine) and IC-ICP-MS (bromine and iodine). Results show that halogen concentrations in pore water are 15–30 times higher than in rainwater. Mean concentrations of chlorine, bromine and iodine in pore water were 7–15 mg l−1, 56–123 μg l−1, and 10–20 μg l−1, which correspond to mean proportions of 10–15%, 1–2.3% and 0.5–2.2% of total concentrations in peat, respectively. Organobromine and organoiodine were the predominant species in pore waters, whereas chlorine in pore water was mostly chloride. Advection and diffusion of halogens were found to be generally low and halogen concentrations appear to reflect release from the peat substrate. Release of bromine and iodine from peat depend on the degree of peat degradation, whereas this relationship is weak for chlorine. Relatively higher release of bromine and iodine was observed in less degraded peat sections, where the release of dissolved organic carbon (DOC) was also the most intensive. It has been concluded that the release of halogenated dissolved organic matter (DOM) is the predominant mechanism of iodine and bromine release from peat.

scholarly journals Halogens in porewater of peat bogs – the role of peat decomposition and dissolved organic matter

2005 ◽  
Vol 2 (5) ◽  
pp. 1457-1486 ◽  
Author(s):  
H. Biester ◽  
D. Selimović ◽  
S. Hemmerich ◽  
M. Petri
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Peat Bogs ◽  
Minor Importance ◽  
Icp Ms ◽  
Predominant Process ◽  
Halogen Species ◽  
Total Concentrations

Abstract. Peatlands are one of the largest active terrestrial reservoirs of halogens. Formation of organo-halogens is a key process for the retention of halogens by organic matter and halogen enrichment in peat is strongly influenced by climatically controlled humification processes. However, little is known about release and transport of halogens in peat bogs. In this study we investigated the release of halogens from peat in three peat bogs located in the Magellanic Moorlands, southern Chile. Peat porewaters were collected using a sipping technique, which allows in situ sampling down to a depth of more than 6 m. Halogens and halogen species in porewater were determined by ion-chromatography (IC) (chlorine) and IC-ICP-MS (bromine and iodine). Results show that halogen concentrations in porewater are 15–30 times higher than in rainwater suggesting that their release from peat during diagenesis is the major source of halogens in porewater. Mean concentrations of chlorine, bromine and iodine in porewater were 7–15 mg l−1, 56–123μg l−1, and 10–20μg l−1, which correspond to mean proportions of 10–15%, 1–2.3% and 0.5–2.2% of total concentrations in peat, respectively. Organo-bromine and organoiodine were predominant in porewaters, whereas the release of organo-chlorine compounds from peat appears to be of minor importance. Results show that the release of bromine and iodine from peat depend on the degree of peat degradation, whereas this relationship is weak for chlorine. Relatively higher release of bromine and iodine was observed in less degraded peat sections, where the release of dissolved organic carbon (DOC) was also the most intensive. Here, proportions of released iodine and bromine follow proportions of released dissolved organic matter (DOM) indicating that the release of halogenated DOM is the predominant process of iodine and bromine release from peat.

scholarly journals Sediment release of dissolved organic matter to the oxygen minimum zone off Peru

2020 ◽  
Author(s):  
Alexandra N. Loginova ◽  
Andrew W. Dale ◽  
Frédéric A. C. LeMoigne ◽  
Sören Thomsen ◽  
Stefan Sommer ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Pore Water ◽  
Oxygen Minimum Zone ◽  
Water Interface ◽  
Sediment Release ◽  
Bottom Waters ◽  
Minimum Zone ◽  
Oxygen Minimum

Abstract. The eastern tropical South Pacific (ETSP) represents one of the most productive areas in the ocean that is characterized by a pronounced oxygen minimum zone (OMZ). Particulate organic matter (POM) that sinks out of the euphotic zone is supplied to the anoxic sediments and utilized by microbial communities. The degradation of POM is associated with dissolved organic matter (DOM) production and reworking. The release of recalcitrant DOM to the overlying waters may represent an important organic matter escape mechanism from remineralization within sediments but received little attention in OMZ regions so far. Here, we combine measurements of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) with DOM optical properties in the form of chromophoric (CDOM) and fluorescent (FDOM) DOM from pore waters and near-bottom waters of the ETSP off Peru. We evaluate diffusion–driven fluxes and net in situ fluxes of DOC and DON in order to investigate processes affecting DOM cycling at the sediment–water interface along a transect 12° S. To our knowledge, these are the first data for sediment release of DON and pore water CDOM and FDOM for the ETSP off Peru. Pore-water DOC and DON accumulated with increasing sediment depth, suggesting an imbalance between DOM production and remineralization within sediments. High DON accumulation resulted in very low pore water DOC / DON ratios (> 1) which could be caused by either an imbalance in DOC and DON remineralization, or to the presence of an additional nitrogen source. Diffusion driven fluxes of DOC and DON exhibited high spatial variability. They varied from 0.2–0.1 mmol m−2 d−1 to 2.52–1.3 mmol m−2 d−1 and from −0.042–0.02 mmol m−2 d−1 to 3.32–1.7 mmol m−2 d−1, respectively. Generally low net in situ DOC and DON fluxes as well as steepening of spectral slope (S) of CDOM and accumulation of humic-like FDOM at the near-bottom waters over time indicated active microbial DOM utilization at the sediment–water interface, potentially stimulated by nitrate (NO3−) and nitrite (NO2−). The microbial DOC utilization rates, estimated in our study, may be sufficient to support denitrification rates of 0.2–1.4 mmol m−2 d−1, suggesting that sediment release of DOM contributes substantially to nitrogen loss processes in the ETSP off Peru.

scholarly journals Vertical Stratification of Peat Pore Water Dissolved Organic Matter Composition in a Peat Bog in Northern Minnesota

2018 ◽  
Vol 123 (2) ◽  
pp. 479-494 ◽  
Author(s):  
Malak M. Tfaily ◽  
Rachel M. Wilson ◽  
William T. Cooper ◽  
Joel E. Kostka ◽  
Paul Hanson ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Pore Water ◽  
Vertical Stratification ◽  
Peat Bog ◽  
Organic Matter Composition ◽  
Peat Pore Water

scholarly journals Sediment release of dissolved organic matter to the oxygen minimum zone off Peru

2020 ◽  
Vol 17 (18) ◽  
pp. 4663-4679
Author(s):  
Alexandra N. Loginova ◽  
Andrew W. Dale ◽  
Frédéric A. C. Le Moigne ◽  
Sören Thomsen ◽  
Stefan Sommer ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Pore Water ◽  
Nitrogen Loss ◽  
Oxygen Minimum Zone ◽  
Water Interface ◽  
Sediment Release ◽  
Minimum Zone ◽  
Oxygen Minimum

Abstract. The eastern tropical South Pacific (ETSP) represents one of the most productive areas in the ocean that is characterised by a pronounced oxygen minimum zone (OMZ). Particulate organic matter (POM) that sinks out of the euphotic zone is supplied to the anoxic sediments and utilised by microbial communities, and the degradation of POM is associated with the production and reworking of dissolved organic matter (DOM). The release of DOM to the overlying waters may, therefore, represent an important organic matter escape mechanism from remineralisation within sediments but has received little attention in OMZ regions so far. Here, we combine measurements of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) with DOM optical properties in the form of chromophoric (CDOM) and fluorescent (FDOM) DOM from pore waters and near-bottom waters of the ETSP off Peru. We evaluate diffusion-driven fluxes and net in situ fluxes of DOC and DON to investigate processes affecting DOM cycling at the sediment–water interface along a transect at 12∘ S. To our knowledge, these are the first data for sediment release of DON and pore water CDOM and FDOM for the ETSP off Peru. Pore water DOC accumulated with increasing sediment depth, suggesting an imbalance between DOM production and remineralisation within sediments. High DON accumulation resulted in very low pore water DOC ∕ DON ratios (≤1) which could be caused by an “uncoupling” in DOC and DON remineralisation. Diffusion-driven fluxes of DOC and DON exhibited high spatial variability and ranged from 0.2±0.1 to 2.5±1.3 mmolm-2d-1 and from -0.04±0.02 to 3.3±1.7 mmolm-2d-1, respectively. Generally low net in situ DOC and DON fluxes, as well as a steepening of spectral inclination (S) of CDOM and an increase in humic-like DOM at the sediment–water interface over time, indicated active microbial DOM utilisation. The latter may potentially be stimulated by the presence of nitrate (NO3-) and nitrite (NO2-) in the water column. The microbial DOC utilisation rates, estimated in our study, are potentially sufficient to support denitrification rates of 0.2–1.4 mmolm-2d-1, suggesting that the sediment release of DOM may on occasion contribute to nitrogen loss processes in the ETSP off Peru.

Characterization of dissolved organic matter in anoxic rock extracts and in situ pore water of the Opalinus Clay

2007 ◽  
Vol 22 (12) ◽  
pp. 2926-2939 ◽  
Author(s):  
Amandine Courdouan ◽  
Iso Christl ◽  
Sébastien Meylan ◽  
Paul Wersin ◽  
Ruben Kretzschmar
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Pore Water ◽  
Opalinus Clay

Dynamics and chemistry of dissolved organic carbon in Precambrian Shield catchments and an impounded wetland

2003 ◽  
Vol 60 (5) ◽  
pp. 612-623 ◽  
Author(s):  
T R Moore ◽  
L Matos ◽  
N T Roulet
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Pore Water ◽  
Neutral Fraction ◽  
Plant Tissues ◽  
Pore Waters ◽  
Experimental Lakes Area ◽  
Peat Pore Water ◽  
Doc Export

We examined the sources, sinks, and fluxes of dissolved organic carbon (DOC) and its chemical fractions over a 4-year period in upland and wetland catchments in the Experimental Lakes Area, Ontario. In an upland catchment, the major sources of DOC were precipitation, vegetation, and soil organic matter, resulting in a summer (June to October) export of 2.1 g·m–2. DOC concentrations in peat pore water ranged from 20 to 60 mg·L–1 and were related to hydrologic pathways. DOC export from catchments containing wetlands ranged from 0.8 to 5.7 g·m–2 and export from the peatland portion of the catchment was estimated to be 28–30 g·m–2. Flooding to a depth of 1.2 m in the peatland section of one catchment resulted in an increase in pore-water and pond DOC concentrations, attributed to the decomposition of plant tissues and peat. Because only 14% of the catchment was flooded, impoundment did not result in a significant increase in DOC export. Between 85 and 93% of DOC was contained in the acid fractions, with small amounts in the neutral fractions. Flooding increased the proportion of the hydrophilic neutral fraction in peat pore waters for 2 years after flooding.

scholarly journals Enhancement of Photo-bromination of Phenol by Anthraquinone-2-sulphonate and Benzophenone: Implication for Photo-production of Organic Brominated Compounds by Dissolved Organic Matter in Marine Environment

2021 ◽  
Author(s):  
Hui Liu ◽  
Xiaojun Qiu ◽  
Xiaomei Zhu ◽  
Bing Sun ◽  
Xiaoxing Zhang
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Marine Environment ◽  
Bromide Solution ◽  
Reactive Halogen Species ◽  
Organohalogen Compounds ◽  
Halogenation Reaction ◽  
Photo Production ◽  
Halogen Species

Abstract Organobromine compounds are of great ecological risks due to their high toxicity on organisms. Photochemical halogenation reaction may represent an important natural formation process of natural organobromine compounds in marine environment. Here we reported the enhanced formation of bromophenols from phenol by sunlit anthraquinone-2-sulphonate (AQ2S) and benzophenone (BP) in aqueous bromide solutions. Quinones and aromatic ketones are ubiquitous components of dissolved organic matter (DOM) in surface waters, and AQ2S and BP were adopted here as proxies of DOM. Bromophenols’ formation increased with the increasing of the concentrations of AQ2S and BP, and the promotion effect was in the order AQ2S > BP, indicating that sunlit DOM plays an important role for the formation of reactive bromine species. Chloride was found to promote the formation of bromophenols obviously, suggesting a possible role of the mixed reactive halogen species. Finally, the natural DOM from Suwannee River was found to enhance photobromoination at a low concentration (1 mg L-1) in aqueous bromide solution. Our results demonstrated the importance of reactive halogen species generation from sunlit DOM, which possibly contributes to the abiotic source of organohalogen compounds in marine environment.

Sign in / Sign up

Export Citation Format

Share Document