Release of weak and strong copper‐complexing agents by algae1

McKnight, Diane M.; Morel, François M. M.

doi:10.4319/lo.1979.24.5.0823

Cited by 213 publications

(69 citation statements)

References 20 publications

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“…Mesocosms that received nutrient additions exhibited greatly increased rates of primary productivity (Breitburg et al 1999;Riedel et al 2003). This increase in total dissolved Cu may be due to the production of dissolved organic ligands which served to keep more of the added Cu in solution (e.g., McKnight and Morel 1979;Teresa et al 2001). In support of this, a small but significant increase (4-6%) in mean dissolved organic carbon occurred in the nutrient treatments.…”

Section: Treatment Effects On Dissolved Trace Elementsmentioning

confidence: 99%

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The interrelationships among trace element cycling, nutrient loading, and system complexity in estuaries: A mesocosm study

Riedel¹,

Sanders

2003

Estuaries

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Biogeochemical interactions between a suite of trace elements and nutrients were examined in a series of experimental mesocosm experiments to understand how multiple stressors affect estuarine environments and how these effects are modified by the complexity of the system used to examine them. Experimental treatment included additions of nutrients and trace elements separately and combined, along with a gradient in experimental system complexity. Eight mesocosm experiments were carried out from 1996 through 1998. Increased nutrients generally decreased dissolved trace element concentrations, in large part through an increase in phytoplankton biomass, but also by increasing the concentration of metals in the particles. Trace element additions increased dissolved nutrients by decreasing phytoplankton biomass. The presence of sediments reduced both dissolved trace element and nutrient concentrations. Other complexity treatments had weaker effects on both dissolved nutrients and trace elements. Many of the observed effects appeared to be seasonal, occurring only in spring, or their magnitude was greater in spring. This may be linked to a change from phosphorus to nitrogen limitation that often occurs in the Patuxent River estuary in the late spring or early summer period.

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Section: Treatment Effects On Dissolved Trace Elementsmentioning

confidence: 99%

“…If the larger cells had higher K D than the smaller cells replacing them, the K D of the particles in the trace element treatments could be reduced. Finally, the added trace elements may have stimulated the production of dissolved or colloidal ligands, which would also lower the K D (McKnight and Morel 1979;Moran et al 1996). …”

mentioning

confidence: 99%

The interrelationships among trace element cycling, nutrient loading, and system complexity in estuaries: A mesocosm study

Riedel¹,

Sanders

2003

Estuaries

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“…The Cu complexation potential in Pond 2 would be expected to vary seasonally and be a function of algal concentration McKnight and Morel, 1979). 726…”

Section: Resultsmentioning

confidence: 99%

Surficial Lime Slurry Application to Exposed Tailings During Wet Closure

Evans¹

1995

JASMR

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The wet closure of exposed tailings is a remediation technology that has been used to reduce or eliminate the toxicity and mobility of.heavy metal contaminants. For constructed wet closure cells, the application of this technology is easily accomplished and chemical amendments can be readily added, as needed, to control pH and dissolved metal concentrations. As part of the Warm Springs Ponds site remediation, exposed shoreline tailings located on the southern perimeter of Pond 2 in the Active Area of the Warm Springs Ponds Operable Unit of the Silver Bow Creek/Butte Area NPL Site (Anaconda, MT), were to be wet closed. During the flooding of these tailings, Pond 2 discharge was required to meet Interim Water Quality Standards and the impact of this remediation action on aquatic life was to be minimized. To address this problem, a series of soil column studies were undertaken to evaluate the suitability of direct surficial lime additions to exposed tailings. Results of these studies indicated that lime slurry application rate of 8.96 Mg ha·• (4.0 ton/acre) would be optimal in· reducing metal release into the overlying water column. Monitoring of dissolved metal concentration in Pond 2 discharge during the Pond raise showed slightly higher dissolved Cu concentrations (0.055 -0.105 mg/L) than predicted from column studies (0.050 mg/L). Complexation of dissolved Cu with organic exudates originating from a corresponding algal bloom in Pond 2 was believed responsible for the difference. Surficial lime application to exposed tailings prior to wet closure was effective in reducing metals release from tailings into the overlying water.Additional

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“…Many papers have appeared in the literature on the release of extracellular metal binding organic matter (EMBO) by marine and freshwater phytoplankton, mainly for as regards copper binding ability (Stolzberg and Rosin, 1977;McKnight and Morel, 1979;van den Berget al, 1979;Fisher and Frood, 1980;Fisher and Fabris, 1982;Sueur et al 1982;Seritti et al, 1986;Simoes Goncalves and Lopes da Conceicao, 1989;Ogiwara and Kodaira, 1989). Recent field studies also indicate a correlation between the biological activity and the presence of organic material capable of complexing copper (Zhou and Wangersky, 1989;van den Berg and de Luca Rebello, 1986).…”

Section: Introductionmentioning

confidence: 99%

Copper binding ability of the extracellular organic matter released by Skeletonema costatum

Morelli

Scarano

Ganni

et al. 1989

Chemical Speciation & Bioavailability

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The copper complexing ability of the exudates produced during the exponential growth phase by Skeletonema costatum has been investigated by a ligand-competition technique involving copper sorption onto C-18 Sep-Pak cartridges. Two ligands with different affinity for copper were required for the best fit of the copper complexation data in seawater with and without exudates: a strong ligand with a log K close to 13 and a weaker ligand with a log K close to 9. The culture increased both L 1 and L2 ligand concentrations, already present in seawater, by a factor close to 4 after the first 72 hours of growth. The presence of class 1 stronger ligands in copper binding organics produced by the diatom is discussed in relation to natural copper speciation in the sea.

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Release of weak and strong copper‐complexing agents by algae1

Abstract: By means of potentiometric titrations, the copper-complcxing properties of organic compounds released by 21 algal species are characterized.

Cited by 213 publications

References 20 publications

The interrelationships among trace element cycling, nutrient loading, and system complexity in estuaries: A mesocosm study

The interrelationships among trace element cycling, nutrient loading, and system complexity in estuaries: A mesocosm study

Surficial Lime Slurry Application to Exposed Tailings During Wet Closure

Copper binding ability of the extracellular organic matter released by Skeletonema costatum

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