Oxygen consumption in humic-colored waters by a photochemical ferrous-ferric catalytic cycle

Miles, Carl J.; Brezonik, Patrick L.

doi:10.1021/es00091a010

Cited by 256 publications

(162 citation statements)

References 8 publications

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“…The difference in Fe(II) oxidation between the water types might therefore be due to the stabilisation of Fe(II) against oxidation by natural occurring compounds of the natural SW (Miles and Brezonik, 1981;Rose and Waite, 2003a;Santana-Casiano et al, 2000;Santana-Casiano et al, 2004;Theis and Singer, 1974). These results show that the added gum xanthan was not a good model for natural occurring substances which stabilize Fe(II) against oxidation.…”

Section: Experiments 2: Effect Of Gum Xanthan On the Oxidation Of Fe(imentioning

confidence: 90%

“…This oxidation can be inhibited (Miles and Brezonik, 1981;Theis and Singer, 1974) or accelerated (Rose and Waite, 2002;Rose and Waite, 2003a;Sedlak and Hoigne, 1993) in the presence of organic compounds. The decrease in apparent oxidation rate is suggested to be due to stronger photoreduction of Fe(III) in the upper ocean Published by Copernicus Publications on behalf of the European Geosciences Union.…”

Section: Introductionmentioning

confidence: 99%

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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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Section: Experiments 2: Effect Of Gum Xanthan On the Oxidation Of Fe(imentioning

confidence: 90%

Section: Introductionmentioning

confidence: 99%

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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“…For example, even the very term dystrophy is controversial, because it suggests only the lack of nutrients in lakes (Hansen 1962), while the lack of nutrients is also linked with a higher amount of humic substances (HS), giving brown water color and low pH (4.0-6.0). The other characteristic features of humic lakes include peat-covered catchment area, sometimes overgrown with coniferous forests, peat mosses in the vicinity of water bodies, spreading floating mats on water surfaces, low water and sediment calcium content, dy sediments, small algal biomass, poor taxonomic biodiversity, and higher respiration than primary production (Miles and Brezonik 1981;Salonen et al 1983;Wetzel 1983;Hessen and Tranvik 1998;Górniak et al 1999;Brönmark and Hansson 2005;Gąbka and Owsianny 2006;Poniewozik et al 2011;Rodriguéz et al 2011). Large amounts of humus flow into lakes from catchment basins (De Haan 1992;Hessen 1992), causing water acidification (Kullberg et al 1993).…”

Section: Introductionmentioning

confidence: 99%

Developmental Changes in the Historical and Present-Day Trophic Status of Brown Water Lakes. Are Humic Water Bodies a Uniform Aquatic Ecosystem?

Drzymulska

Zieliński

2013

Wetlands

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The long-term development of three humic lake ecosystems in Poland was investigated through palaeoecological analyses of sediment cores. These wetland records spanning the Holocene were analyzed for plant macroremains, degree of peat decomposition, sediment geochemistry along with radiocarbon dating. Morphological characteristics of the catchments and data on contemporary water quality and management approaches were integrated. Our research on the palaeoecology of humic lakes suggests two main states: humic and eutrophic-humic. Of the lakes studied, only one consistently presented features typical of the humic type. The other two showed various states, and dynamic patterns of transformation. The results indicate that these systems can change from humic to eutrophic-humic, and back again, in response to catchment-linked factors, climatic change and human impact. Thus determination of uniform pattern in the development of humic lakes is questionable. This suggests that a reassessment of brown water lakes is necessary.

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“…Photochemical oxidation of colored dissolved organic matter (CDOM), may explain the hitherto unknown fate of a large portion of the terrestrially derived dissolved organic carbon that enters the ocean [Kieber et al, 1989;Mopper et al, 1991]. Its photochemical products include dissolved inorganic carbon, DIC (CO 2 , HCO 3 À , and CO 3 À2 ); [Chen et al, 1978;Miles and Brezonik, 1981;Allard et al, 1994;Vähätalo et al, 2000;Miller and Zepp, 1995;Granéli et al, 1996;Moore, 1999], CO [Kettle, 1994;Valentine and Zepp, 1993], H 2 O 2 Zika, 1993a, 1993b;Miller and Kester, 1994;Moore et al, 1993], OH . Mopper and Zhou, 1990], oxygen radicals [Cooper et al, 1989;Blough and Zepp, 1995], and many small, biologically labile organic molecules [Bushaw et al, 1996;Moran and Zepp, 1997].…”

Section: Introductionmentioning

confidence: 99%

Calculation of UV attenuation and colored dissolved organic matter absorption spectra from measurements of ocean color

2003

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[1] The absorption of ultraviolet and visible radiation by colored or chromophoric dissolved organic matter (CDOM) drives much of marine photochemistry. It also affects the penetration of ultraviolet radiation (UV) into the water column and can confound remote estimates of chlorophyll concentration. Measurements of ocean color from satellites can be used to predict UV attenuation and CDOM absorption spectra from relationships between visible reflectance, UV attenuation, and absorption by CDOM. Samples were taken from the Bering Sea and from the Mid-Atlantic Bight, and water types ranged from turbid, inshore waters to the Gulf Stream. We determined the following relationships between in situ visible radiance reflectance, L u /E d (l) (sr À1 ), and diffuse attenuation of UV,. Consistent with published observations, these empirical relationships predict that the spectral slope coefficient of CDOM absorption increases as diffuse attenuation of UV decreases. Excluding samples from turbid bays, the ratio of the CDOM absorption coefficient to K d is 0.90 at 323 nm, 0.86 at 338 nm, and 0.97 at 380 nm. We applied these relationships to SeaWiFS images of normalized water-leaving radiance to calculate the CDOM absorption and UV attenuation in the Mid-Atlantic Bight in May, July, and August 1998. The images showed a decrease in UV attenuation from May to August of approximately 50%. We also produced images of the areal distribution of the spectral slope coefficient of CDOM absorption in the Georgia Bight. The spectral slope coefficient increased offshore and changed with season.

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Oxygen consumption in humic-colored waters by a photochemical ferrous-ferric catalytic cycle

Cited by 256 publications

References 8 publications

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

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

Developmental Changes in the Historical and Present-Day Trophic Status of Brown Water Lakes. Are Humic Water Bodies a Uniform Aquatic Ecosystem?

Calculation of UV attenuation and colored dissolved organic matter absorption spectra from measurements of ocean color

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