Toxicity of Heavy Metals to the Marine Diatom Ditylum Brightwellii (West) Grunow: Correlation between Toxicity and Metal Speciation

The possibility of dissolved organic compounds acting as complexing or chelating agents in natural waters has received considerable attention in the last two to three decades. Stumm & Morgan (1970) have expressed doubts about the existence of humicmetal ion complexes in natural waters. Strickland (1972) has also stated that although the addition of chelating agents to sea water often improved the growth of phytoplankton, there was little evidence that the function of dissolved organic matter in oceans and lakes was to complex metals so as to increase or decrease their availability to phytoplankton. Strickland argued that even if all dissolved organic carbon were present as a compound of strong complexing ability it would not be able to compete for most metals with inorganic ligands such as chloride, sulphate and hydroxide. However, there is an increasing amount of data indicating that metals in natural waters may exist in chelated forms with dissolved organic matter (see, for example, Davey, Morgan & Erickson, 1973; Chau & Lum-Shue-Chan, 1974).

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Behaviour of dissolved organic matter and inorganic nutrients during experimental sea-ice formation

Annals of Glaciology ◽

10.3189/172756401781818572 ◽

2001 ◽

Vol 33 ◽

pp. 317-321 ◽

Cited By ~ 54

Author(s):

Virginia Giannelli ◽

David N. Thomas ◽

Christian Haas ◽

Gerhard Kattner ◽

Hilary Kennedy ◽

...

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Sea Ice ◽

Organic Compounds ◽

Sea Water ◽

Ice Cores ◽

Inorganic Nutrients ◽

Ice Formation ◽

Solid Matrix ◽

Dissolved Organic Compounds

AbstractIt is well established that during sea-ice formation, crystals aggregate into a solid matrix, and dissolved sea-water constituents, including inorganic nutrients, are rejected from the ice matrix. However, the behaviour of dissolved organic matter (DOM) during ice formation and growth has not been studied to date. DOM is the primary energetic substrate for microbial heterotrophic activity in sea water and sea ice, and therefore it is at the base of the trophic fluxes within the microbial food web. The aim of our study was to compare the behaviour of DOM and inorganic nutrients during formation and growth of sea ice. Experiments were conducted in a large indoor ice-tank facility (Hamburg Ship Model Basin, Germany) at −15°C. Three 1 m3 tanks, to which synthetic sea water, nutrients and dissolved organic compounds (diatom-extracted DOM) had been added, were sampled over a period of 5 days during sea-ice formation. Samples were collected throughout the experiment from water underlying the ice, and at the end from the ice as well. Brine was obtained from the ice by centrifuging ice cores. Inorganic nutrients (nitrate and phosphate) were substantially enriched in brine in comparison to water and ice phases, consistent with the processes of ice formation and brine rejection. Dissolved organic carbon (DOC) was also enriched in brine but was more variable and enriched in comparison to a dilution line. No difference in bacteria numbers was observed between water, ice and brine. No bacteria growth was measured, and this therefore had no influence on the measurable DOC levels. We conclude that the incorporation of dissolved organic compounds in newly forming ice is conservative. However, since the proportions of DOC in the brine were partially higher than those of the inorganic nutrients, concentrating effects of DOC in brine might be different compared to salts.

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Trace metal speciation predictions in natural aquatic systems: incorporation of dissolved organic matter (DOM) spectroscopic quality

Environmental Chemistry ◽

10.1071/en11156 ◽

2012 ◽

Vol 9 (4) ◽

pp. 356 ◽

Cited By ~ 34

Author(s):

Kristin K. Mueller ◽

Stephen Lofts ◽

Claude Fortin ◽

Peter G. C. Campbell

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Trace Metal ◽

Metal Binding ◽

Natural Waters ◽

Metal Speciation ◽

Chemical Species ◽

Metal Species ◽

Fluorescence Measurements ◽

Shield Lakes

Environmental contextTo assess the risk posed by environmental contaminants such as metals, one needs to be able to identify the key chemical species that prevail in natural waters. One of the recognised stumbling blocks is the need to quantify the influence of heterogeneous dissolved organic matter (DOM). Here we explore the possibility of using the optical signature of DOM to determine its quality, to alleviate the need to make assumptions about its metal-binding properties and to improve the prediction of trace metal species distributions in natural waters. AbstractTo calculate metal speciation in natural waters, modellers must choose the proportion of dissolved organic matter (DOM) that is actively involved in metal complexation, defined here as the percentage of active fulvic acid (FA); to be able to estimate this proportion spectroscopically would be very useful. In the present study, we determine the free Cd2+, Cu2+, Ni2+ and Zn2+ concentrations in eight Canadian Shield lakes and compare these measured concentrations to those predicted by the Windermere Humic Aqueous Model (WHAM VI). For seven of the eight lakes, the measured proportions of Cd2+ and Zn2+ fall within the range of values predicted by WHAM; the measured proportion of Cu2+ falls within this range for only half of the lakes sampled, whereas for Ni, WHAM systematically overestimated the proportion of Ni2+. With the aim of ascribing the differences between measured and modelled metal speciation to variations in DOM quality, the percentage of active FA needed to fit modelled and measured free metal concentrations was compared with the lake-to-lake variation in the spectroscopic quality of the DOM, as determined by absorbance and fluorescence measurements. Relationships between the percentage of active FA and DOM quality were apparent for Cd, Cu, Ni and Zn, suggesting the possibility of estimating the percentage of active FA spectroscopically and then using this information to refine model predictions. The relationships for Ni differed markedly from those observed for the other metals, suggesting that the DOM binding sites active in Cd, Cu and Zn complexation are different from those involved in Ni complexation. To our knowledge, this is the first time that such a distinction has been resolved in natural water samples.

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Photochemical effects on the interaction of enzymes and dissolved organic matter in natural waters

Limnology and Oceanography ◽

10.4319/lo.2003.48.5.1818 ◽

2003 ◽

Vol 48 (5) ◽

pp. 1818-1824 ◽

Cited By ~ 23

Author(s):

Norman M. Scully ◽

Lars J. Tranvik ◽

William J. Cooper

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Natural Waters

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Effect of dissolved organic matter composition on metal speciation in soil solutions

Chemical Geology ◽

10.1016/j.chemgeo.2015.01.020 ◽

2015 ◽

Vol 398 ◽

pp. 61-69 ◽

Cited By ~ 67

Author(s):

Zong-Ling Ren ◽

Marie Tella ◽

Matthieu N. Bravin ◽

Rob N.J. Comans ◽

Jun Dai ◽

...

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Metal Speciation ◽

Organic Matter Composition ◽

Soil Solutions

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Optical Properties of Dissolved Organic Matter in Finnish and Estonian Lakes

Hydrology Research ◽

10.2166/nh.2003.0012 ◽

2003 ◽

Vol 34 (4) ◽

pp. 361-386 ◽

Cited By ~ 14

Author(s):

L. Sipelgas ◽

H. Arst ◽

K. Kallio ◽

A. Erm ◽

P. Oja ◽

...

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Natural Waters ◽

Mean Value ◽

Published Data ◽

Optical Parameters ◽

Exponential Approximation ◽

Absorption Coefficients ◽

Specific Absorption ◽

The Mean

The main objective of the present study is to test various methods for describing the absorption spectra of coloured dissolved organic matter (CDOM) and to determine the numerical values of some optical parameters of CDOM in lakes with diverse water quality. First, the parameters of an exponential model in different spectral intervals were determined. In addition, the suitability of some other models for the approximation of CDOM spectra was estimated. Specific absorption coefficients of CDOM were calculated from the absorption coefficients and dissolved organic carbon (DOC) concentrations. The experimental initial data were differences between spectral attenuation coefficients of filtered and distilled water. Two datasets were used: 1) for 13 Estonian and 7 Finnish lakes (altogether 404 spectra between 350 and 700 nm) measured by the Estonian Marine Institute (EMI); 2) for 10 Finnish lakes (73 spectra) measured by the Finnish Environment Institute (FEI). The spectra of CDOM absorption coefficients (aCDOM) were calculated from experimental data taking into account the correction due to scattering properties of colloids in the filtered water. The total content of CDOM in natural waters of Estonian and Finnish lakes was expressed by means of aCDOM at the wavelength of 380 nm. It varied significantly, from 0.71 to 19.5 m−1, the mean value (of all the investigated lakes) being around 6.6 m−1. Slopes of the exponential approximation varied widely, from 0.006 to 0.03 nm−1. Averaged over all lakes values of slope for the interval 380-500 nm obtained from the EMI dataset are close to those obtained from the FEI dataset: from 0.014 nm−1 (without correction) to 0.016-0.017 nm-1 (with different types of correction). These results are in good correspondence with most published data. Attempts to describe the spectra in the region of 350-700 nm by means of hyperexponential functions (∽ exp(-αλη)) show that: (1) η < 1 (in the case of traditional exponential approximation η = 1); (2) a promising idea is to seek the best fit only for wavelengths λ > λ1, where λ1 will be chosen taking into account the real shape of aCDOM spectra. The mean value of the specific absorption coefficient (a*CDOM) at the wavelength 380 nm obtained in this study (0.44 L mg−1 m−1) is close to the values published in the literature, if we assume that a*CDOM (380) is calculated using the data of dissolved organic matter (DOM). The optically non-active fraction of DOM in our study was high and therefore a*CDOM (380) was considerably higher (1.01 L mg−1 m−1) than a*CDOM (380). The results of the present work could be used in the modeling of underwater light field as well as in the interpretation of radiation measurements and optical remote sensing results.

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Heavy-metal pollution alters dissolved organic matter released by bloom-forming Microcystis aeruginosa

RSC Advances ◽

10.1039/c7ra00414a ◽

2017 ◽

Vol 7 (30) ◽

pp. 18421-18427 ◽

Cited By ~ 4

Author(s):

Haiming Wu ◽

Li Lin ◽

Guangzhu Shen ◽

Ming Li

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Organic Matter ◽

Dissolved Organic Matter ◽

Microcystis Aeruginosa ◽

Metal Pollution ◽

Heavy Metal Pollution ◽

Aquatic Ecosystems ◽

Eutrophic Lakes

The risk of heavy metals to aquatic ecosystems was paid much attention in recent years, however, the knowledge on effects of heavy metals on dissolved organic matter (DOM) released byMicrocystiswas quite poor, especially in eutrophic lakes.

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Evidence for significant protein-like dissolved organic matter accumulation in Sea of Okhotsk sea ice

Annals of Glaciology ◽

10.3189/2015aog69a002 ◽

2015 ◽

Vol 56 (69) ◽

pp. 1-8 ◽

Cited By ~ 12

Author(s):

Mats A. Granskog ◽

Daiki Nomura ◽

Susann Müller ◽

Andreas Krell ◽

Takenobu Toyota ◽

...

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Sea Ice ◽

Surface Waters ◽

Sea Of Okhotsk ◽

Sea Water ◽

First Year ◽

Ice Melt ◽

Ultraviolet Range ◽

Considerable Excess

AbstractAbsorption and fluorescence of chromophoric dissolved organic matter (CDOM) in sea ice and surface waters in the southern Sea of Okhotsk was examined. Sea-water CDOM had featureless absorption increasing exponentially with shorter wavelengths. Sea ice showed distinct absorption peaks in the ultraviolet, especially in younger ice. Older first-year sea ice had relatively flat absorption spectra in the ultraviolet range. Parallel factor analysis (PARAFAC) identified five fluorescent CDOM components, two humic-like and three protein-like. Sea water was largely governed by humic-like fluorescence. In sea ice, protein-like fluorescence was found in considerable excess relative to sea water. The accumulation of protein-like CDOM fluorescence in sea ice is likely a result of biological activity within the ice. Nevertheless, sea ice does not contribute excess CDOM during melt, but the material released will be of different composition than that present in the underlying waters. Thus, at least transiently, the CDOM introduced during sea-ice melt might provide a more labile source of fresher protein-like DOM to surface waters in the southern Sea of Okhotsk.

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