Analysis of copper and calcium–fulvic acid complexation and competition effects

Iglesias, A.; López, R.; Fiol, Sarah; Antelo, Juan; Arce, F.

doi:10.1016/s0043-1354(03)00236-7

Cited by 42 publications

(24 citation statements)

References 21 publications

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“…The threshold concentrations of Cu(II) for causing the aggregation and precipitation of HA were reported to be 50 and 140 μM, respectively. 31 The level of Cu(II) used in this study failed to result in either aggregation or precipitation. Therefore, the precipitation in this study can be attributed to the relatively high concentrations of Ca 2+ and Mg 2+ in seawater.…”

Section: Influence Of Cu(ii) Concentration On Co-precipitationmentioning

confidence: 71%

Removal of Trace Levels of Cu(II) from Seawater by Co-precipitation with Humic Acids

Iwai

2017

ANAL. SCI.

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To maintain performance related to fuel consumption and maneuverability, the bottom of ships are painted with antifouling paint that contains Cu2O as a biocidal pigment. However, in enclosed coastal areas around dockyards, some of the Cu(II) contained in the paint is eluted into the surrounding water. The present study examined the removal of Cu from seawater by co-precipitation with humic acids (HAs). After precipitating the HA in seawater, the amount of Cu(II) in the supernatant was colorimetrically measured by a colorimetry using bathocuproine. The removal efficiency (RE%) for micromolar Cu(II) increased with increasing initial concentrations of HAs. An RE of 90% was obtained using an HA derived from hardwood bark compost. Aromatic components in the HA that contained highly substituted acidic functional groups appeared to enhance the removal of Cu(II). The findings reported herein indicate that HAs represent a useful material for removing trace levels of Cu from seawater.

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Section: Influence Of Cu(ii) Concentration On Co-precipitationmentioning

confidence: 71%

Removal of Trace Levels of Cu(II) from Seawater by Co-precipitation with Humic Acids

Iwai

2017

ANAL. SCI.

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“…Mantoura et al [19] reported that Mg and Ca compete with Cu for binding sites on the humic acid molecule. Similarly, Iglesias et al [38] found that the degree of Cu complexation with fulvic acid decreased as the concentration of Ca 2þ in the exposure medium increased. This would indicate that DOC would be more effective at reducing the bioavailability of Cu in soft water than in hard water.…”

Section: Effect Of Doc On Cu Toxicity To Glochidiamentioning

confidence: 79%

The effect of natural dissolved organic carbon on the acute toxicity of copper to larval freshwater mussels (glochidia)

Gillis

McGeer

Mackie

et al. 2010

Enviro Toxic and Chemistry

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The present study examined the effect of dissolved organic carbon (DOC), both added and inherent, on Cu toxicity in glochidia, the larvae of freshwater mussels. Using incremental additions of natural DOC concentrate and reconstituted water, a series of acute copper toxicity tests were conducted. An increase in DOC from 0.7 to 4.4 mg C/L resulted in a fourfold increase (36 150 mg Cu/L) in the 24 h median effective concentration (EC50) and a significant linear relationship (r 2 0.98, p 0.0008) between the DOC concentration and the Cu EC50 of Lampsilis siliquoidea glochidia. The ameliorating effect of added DOC on Cu toxicity was confirmed using a second mussel species, the endangered (in Canada) Lampsilis fasciola. The effect of inherent (i.e., not added) DOC on Cu toxicity was also assessed in eight natural waters (DOC 5 15 mg C/L). These experiments revealed a significant relationship between the EC50 and the concentration of inherent DOC (r 2 0.79, p 0.0031) with EC50s ranging from 27 to 111 mg Cu/L. These laboratory tests have demonstrated that DOC provides glochidia with significant protection from acute Cu toxicity. The potential risk that Cu poses to mussel populations was assessed by comparing Cu and DOC concentrations from significant mussel habitats in Ontario to the EC50s. Although overall mean Cu concentration in the mussel's habitat was well below the acutely toxic level given the concentration of DOC, episodic Cu releases in low DOC waters may be a concern for the recovery of endangered freshwater mussels. The results are examined in the context of current Cu water quality regulations including the U.S. Environmental Protection Agency's (U.S. EPA) biotic ligand model.

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“…They reported Cu 2+ loadings ranging from 5 · 10 -6 mol/ g DOC to 5 · 10 -4 mol/g DOC after titrating 15 different water samples taken from lakes, ponds, streams and rivers in North Western part of the UK, using similar ISE titration method with samples buffered at pH 6 and ionic strength of 0.1 M KNO 3 based on an initial total Cu 2+ concentration of 10 -6 M. David and Vance (1991) showed that hydrophobic and hydrophilic acids differ in their proton-binding capacities, and that lake water samples differ from stream samples (David and Vance 1991). Iglesias et al (2003) reported mean Cu 2+ -binding constant values of 5 (at pH 5.5) and 5.29 (at pH 6.5) while titrating dissolved isolated fulvic acid sample simulating natural water samples, at ionic strength of 0.1 M KNO 3 and DOM concentration of 100 mg/L (fulvic acid). Lu and Allen (2002) reported Cu 2+ -binding in three different DOM samples extracted by Reverse Osmosis and getting small amounts of strong Cu-binding sites, a total of 4.55 mmol/g DOC, which was much less than the total acidity (carboxylic and phenolic) but very close to the phenolic site content.…”

Section: Resultsmentioning

confidence: 99%

Copper Binding by Dissolved Organic Matter in Freshwaters in Kenya

Lalah

Wandiga

2007

Bull Environ Contam Toxicol

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The binding of Cu2+ to dissolved organic matter in eight different natural water samples obtained from different locations in Kenya was studied by potentiometric titration method. The DOC contents of the eight natural water samples ranged from 2.71 to 374 mg/L. The water samples were adjusted to a uniform background electrolyte concentration of 0.5 M NaNO(3) and pH 6 and the temperature maintained at 20 degrees C during the assay. A Nernst equation E (mV) = -32.175 pCu + 305.5 (R (2) = 0.9996) obtained for the Cu2+ calibration standards (10(-4)-10(-6) M) was used to determine the concentration of free and bound Cu2+, respectively. The bound [Cu2+] varied by a factor of 2, ranging from 2.67 x 10(-3) mol/kg DOC (in a high DOC alkaline lake water sample) to 3.2962 x 10(-1) mol/kg (in a low DOC river water sample). The binding constants (Log K) varied by a factor of 2 and ranged from 3.43 to 5.57. The percentage binding ranged from 87% to almost 100% in the eight natural water samples. A Suwannee River Fulvic Acid standard sample (40 mg/L DOC) was used for comparison and for validation of the method.

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Analysis of copper and calcium–fulvic acid complexation and competition effects

Cited by 42 publications

References 21 publications

Removal of Trace Levels of Cu(II) from Seawater by Co-precipitation with Humic Acids

Removal of Trace Levels of Cu(II) from Seawater by Co-precipitation with Humic Acids

The effect of natural dissolved organic carbon on the acute toxicity of copper to larval freshwater mussels (glochidia)

Copper Binding by Dissolved Organic Matter in Freshwaters in Kenya

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