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

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.

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

Biogeosciences ◽

10.5194/bg-3-53-2006 ◽

2006 ◽

Vol 3 (1) ◽

pp. 53-64 ◽

Cited By ~ 29

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.

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

Biogeosciences Discussions ◽

10.5194/bgd-2-1457-2005 ◽

2005 ◽

Vol 2 (5) ◽

pp. 1457-1486 ◽

Cited By ~ 7

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.

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Role of Fe(III), Phosphate, Dissolved Organic Matter, and Nitrate during the Photodegradation of Domoic Acid in the Marine Environment

Environmental Science & Technology ◽

10.1021/es051443b ◽

2006 ◽

Vol 40 (7) ◽

pp. 2200-2205 ◽

Cited By ~ 67

Author(s):

Justina M. Fisher ◽

James G. Reese ◽

Perry J. Pellechia ◽

Peter L. Moeller ◽

John L. Ferry

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Marine Environment ◽

Domoic Acid

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Examining the Role of Quinone Moieties in the Photochemistry of Colored Dissolved Organic Matter in Coastal Waters

10.21236/ada627292 ◽

2001 ◽

Author(s):

Catherine D. Clark

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Coastal Waters ◽

Colored Dissolved Organic Matter

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Examining the Role of Quinone Moieties in the Photochemistry of Colored Dissolved Organic Matter in Coastal Waters

10.21236/ada628919 ◽

2002 ◽

Author(s):

Catherine D. Clark

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Coastal Waters ◽

Colored Dissolved Organic Matter

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DOM degradation by light and microbes along the Yukon River-coastal ocean continuum

Scientific Reports ◽

10.1038/s41598-021-89327-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Brice K. Grunert ◽

Maria Tzortziou ◽

Patrick Neale ◽

Alana Menendez ◽

Peter Hernes

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Salinity Gradient ◽

Coastal Ocean ◽

Interactive Effects ◽

The Arctic ◽

Yukon River ◽

Spring Freshet ◽

Dom Composition

AbstractThe Arctic is experiencing rapid warming, resulting in fundamental shifts in hydrologic connectivity and carbon cycling. Dissolved organic matter (DOM) is a significant component of the Arctic and global carbon cycle, and significant perturbations to DOM cycling are expected with Arctic warming. The impact of photochemical and microbial degradation, and their interactive effects, on DOM composition and remineralization have been documented in Arctic soils and rivers. However, the role of microbes, sunlight and their interactions on Arctic DOM alteration and remineralization in the coastal ocean has not been considered, particularly during the spring freshet when DOM loads are high, photoexposure can be quite limited and residence time within river networks is low. Here, we collected DOM samples along a salinity gradient in the Yukon River delta, plume and coastal ocean during peak river discharge immediately after spring freshet and explored the role of UV exposure, microbial transformations and interactive effects on DOM quantity and composition. Our results show: (1) photochemical alteration of DOM significantly shifts processing pathways of terrestrial DOM, including increasing relative humification of DOM by microbes by > 10%; (2) microbes produce humic-like material that is not optically distinguishable from terrestrial humics; and (3) size-fractionation of the microbial community indicates a size-dependent role for DOM remineralization and humification of DOM observed through modeled PARAFAC components of fluorescent DOM, either through direct or community effects. Field observations indicate apparent conservative mixing along the salinity gradient; however, changing photochemical and microbial alteration of DOM with increasing salinity indicate changing DOM composition likely due to microbial activity. Finally, our findings show potential for rapid transformation of DOM in the coastal ocean from photochemical and microbial alteration, with microbes responsible for the majority of dissolved organic matter remineralization.

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