An investigation ofhydrogen peroxide chemistry in surface waters of Vineyard Sound with H218O2 and 18O2

Moffett, James W.; Zajiriou, Oliver C.

doi:10.4319/lo.1990.35.6.1221

Cited by 120 publications

(110 citation statements)

References 11 publications

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“…Our observed H 2 O 2 half-life in unfiltered Chesapeake Bay surface waters is in good agreement with determinations by Cooper et al (1994). For Bay waters, t 1/2 ranged from 2.49 to 12.2 h. The latter is similar to the 12.6 h half-life for unfiltered Vineyard sound surface waters observed by Moffett and Zafiriou (1990). Loss of MHP in surface waters is faster by nearly a factor of 3.…”

Section: Sample Stability Studiessupporting

confidence: 78%

Photochemical production of hydrogen peroxide and methylhydroperoxide in coastal waters

et al. 2005

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Section: Sample Stability Studiessupporting

confidence: 78%

Photochemical production of hydrogen peroxide and methylhydroperoxide in coastal waters

et al. 2005

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“…Gerringa et al (2004) calculated a net production rate of 7 nmol L −1 h −1 at irradiance levels of 2.8 (UVB), 43 (UVA) and 346 W m −2 (VIS/PAR) in 0.2 µm filtered water from the eastern Atlantic close to the Equator. These low rates are presumably due to lower DOC concentrations and higher decay rates due to colloids or enzymatic activity in natural waters (Moffett and Zafiriou, 1990;Petasne and Zika, 1997). Given that H 2 O 2 plays an important role in the Fe redox-chemistry, our experiments suggest that PS may have a significant indirect effect on Fe redox-speciation due to the enhanced photochemical production of H 2 O 2 .…”

Section: Numerical Modelmentioning

confidence: 87%

The role of polysaccharides and diatom exudates in the redox cycling of Fe and the photoproduction of hydrogen peroxide in coastal seawaters

et al. 2010

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Abstract. The effect of artificial acidic polysaccharides (PS) and exudates of Phaeodactylum tricornutum on the half-life of Fe(II) in seawater was investigated in laboratory experiments. Strong photochemical hydrogen peroxide (H 2 O 2 ) production of 5.2 to 10.9 nM (mg C) −1 h −1 was found in the presence of PS and diatom exudates. Furthermore when illuminated with UV light the presence of algal exudates had a net stabilising effect on ferrous iron in seawater (initial value 100 nmol L −1 ) above that expected from oxidation kinetics. In the dark the PS gum xanthan showed no stabilising effect on Fe(II). The photochemical formation of superoxide (O − 2 ) in the presence of diatom exudates and its reducing effect on Fe(III) appears to result in greater than expected concentrations of Fe(II). A model of the photochemical redox cycle of iron incorporating these processes supported the observed data well. Diatom exudates seem to have the potential to play an important role for the photochemistry of iron in coastal waters.

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“…This ddark decay lifetimeT of H 2 O 2 can vary from hours to weeks in the ocean (Petasne and Zika, 1997), but typically may be around 4 days in the open ocean (Plane et al, 1987). Filtration of seawater to remove the biota typically results in a dramatic reduction in the decay rate of H 2 O 2 (Moffett and Zafiriou, 1990;Petasne and Zika, 1997). Isotopic studies of the decomposition of H 2 O 2 have found that 65-80% of the decay was from catalase activity (reduction to H 2 O and O 2 ) with 20-35% from peroxidase activity (reduction to H 2 O only) (Moffett and Zafiriou, 1990).…”

Section: Redox Cycling Of Iron In Seawatermentioning

confidence: 99%

“…Filtration of seawater to remove the biota typically results in a dramatic reduction in the decay rate of H 2 O 2 (Moffett and Zafiriou, 1990;Petasne and Zika, 1997). Isotopic studies of the decomposition of H 2 O 2 have found that 65-80% of the decay was from catalase activity (reduction to H 2 O and O 2 ) with 20-35% from peroxidase activity (reduction to H 2 O only) (Moffett and Zafiriou, 1990). The amount of colloidal material has also been shown to influence the decay rate of H 2 O 2 (Yuan and Shiller, 2001).…”

Section: Redox Cycling Of Iron In Seawatermentioning

confidence: 99%

Spatial and temporal distribution of Fe(II) and H2O2 during EisenEx, an open ocean mescoscale iron enrichment

et al. 2005

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Copyright Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. concentrations increased at the depth of the chlorophyll maximum when iron concentrations returned to pre-infusion concentrations (b80 pM) possibly due to biological production related to iron reductase activity.In this work, Fe(II) and dissolved iron were used as tracers themselves for subsequent iron infusions when no further SF 6 was added. EisenEx was subject to periods of weak and strong mixing. Slow mixing after the second infusion allowed significant concentrations of Fe(II) and Fe to exist for several days. During this time, dissolved and total iron in the infusion plume behaved almost conservatively as it was trapped between a relict mixed layer and a new rain-induced mixed layer. Using dissolved iron, a value for the vertical diffusion coefficient K z =6.7F0.7 cm 2 s À1 was obtained for this 2-day period. During a subsequent surface survey of the iron-enriched patch, elevated levels of Fe(II) were found in surface waters presumably from Fe(II) dissolved in the rainwater that was falling at this time.Model results suggest that the reaction between uncomplexed Fe(III) and O 2 À was a significant source of Fe(II) during EisenEx and helped to maintain high levels of Fe(II) in the water column. This phenomenon may occur in iron enrichment experiments when two conditions are met: (i) When Fe is added to a system already saturated with regard to organic complexation and (ii) when mixing processes are slow, thereby reducing the dispersion of iron into under-saturated waters. D

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An investigation ofhydrogen peroxide chemistry in surface waters of Vineyard Sound with H218O2 and 18O2

Cited by 120 publications

References 11 publications

Photochemical production of hydrogen peroxide and methylhydroperoxide in coastal waters

Photochemical production of hydrogen peroxide and methylhydroperoxide in coastal waters

The role of polysaccharides and diatom exudates in the redox cycling of Fe and the photoproduction of hydrogen peroxide in coastal seawaters

Spatial and temporal distribution of Fe(II) and H2O2 during EisenEx, an open ocean mescoscale iron enrichment

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