Cadmium and lead interaction with diatom surfaces: A combined thermodynamic and kinetic approach

Gélabert, Alexandre; Pokrovsky, Oleg S.; Schott, Jacques; Boudou, A.; Feurtet‐Mazel, Agnès

doi:10.1016/j.gca.2007.04.034

Cited by 58 publications

(36 citation statements)

References 49 publications

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“…The independence of Zn on pH and other macroscopic parameters of solution variations is at first glance surprising because Zn uptake by phytoplankton is strongly pH-dependent (Ge´labert et al, 2006;Tripathi et al, 2009) and Zn concentration during the bloom often follows that of the Chl a (Luengen et al, 2007). Moreover, the pH is known to be the governing factor of metal adsorption on the surface of photosynthetic microorganisms such as diatoms or cyanobacteria (Ge´labert et al, 2007;Pokrovsky et al, 2008aPokrovsky et al, , 2008b. However, we would like to underline that relatively small pH variations (from 6.7 to 7.2) may not be sufficient to control the adsorption and uptake process from the bulk of lake water; rather, these processes are dominated by local pH gradients in the pristine layer around the photosynthesizing cells.…”

Section: Element Concentration Variation During the Diurnal Photosyntmentioning

confidence: 99%

Diurnal variations of trace metals and heterotrophic bacterioplankton concentration in a small boreal lake of the White Sea basin

Shirokova

Pokrovsky

Viers

et al. 2010

Ann. Limnol. - Int. J. Lim.

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-This work represents a concerted effort aimed at understanding the microbiological and chemical evolution of a small boreal lake during the diurnal cycle of photosynthesis. We studied diurnal variation of y 40 dissolved macro-and trace elements, organic carbon and bacterial population dynamics in the surface and bottom water layer of the shallow Vilno Lake in the White Sea basin. Four-days continuous measurements with 6 h sampling steps both at the surface (0.5 m) and on the bottom (4.0 m depth) during no-bloom periods revealed constant concentrations (within ¡ 20-30%) of all major elements (Na, Mg, Si, K, Ca), organic and inorganic carbon and most trace elements (B, V, Cr, Fe, Cu, Ga, As, Rb, Sr, Y, Zr, Sb, Cs, Ba, all REEs, Hf, Pb, Th, U). At the same time, the concentration of some biologically important trace metals (Mo, Mn, Co, Cd) was subjected to variations partially reflecting the change of bacterioplankton concentration. This work enables two types of element behavior to be distinguished during photosynthesis in the water column -constant concentration and sinusoidal variations -depending on their speciation in solution and their affinity to aquatic microorganisms.

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Section: Element Concentration Variation During the Diurnal Photosyntmentioning

confidence: 99%

Diurnal variations of trace metals and heterotrophic bacterioplankton concentration in a small boreal lake of the White Sea basin

Shirokova

Pokrovsky

Viers

et al. 2010

Ann. Limnol. - Int. J. Lim.

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“…15 µg/L at pH from 3 to 12, but decreased three-fold and then remained relatively constant or increased in the NaCl electrolyte. Net adsorption of AuNPs at the diatom surface is due to competition with H + for negativelycharged anionic surface sites (phosphorylates, sulphides), as it is fairly well established for divalent metals interacting with diatoms [31,34] and various bacteria [45]. The desorption with the increase of pH may be due to competition between aqueous ligands complexing AuNPs + particles and surface site moieties.…”

Section: Dependence Of Adsorption Of Phmentioning

confidence: 95%

“…Monospecific diatom cultures were developed from laboratory strains to produce a biomass of freshwater periphytic Eolimna minima (EOMI), as described previously [31,[34][35][36][37]. Diatoms were cultured to a concentration of~10 7 cell/L at 20 • C in a sterile Dauta freshwater medium [38] at pH~7.7-7.8.…”

Section: Diatom Culturesmentioning

confidence: 99%

“…This and the previously described result may have important consequences for understanding the AuNPs interaction with photosynthesizing diatoms cells. It is possible that during the active phase of photosynthesis, during the day, when the pH in the pristine water layer surrounding the cells rises above 9, the diatoms will release AuNPs that were Net adsorption of AuNPs at the diatom surface is due to competition with H + for negatively-charged anionic surface sites (phosphorylates, sulphides), as it is fairly well established for divalent metals interacting with diatoms [31,34] and various bacteria [45]. The desorption with the increase of pH may be due to competition between aqueous ligands complexing AuNPs + particles and surface site moieties.…”

Section: Dependence Of Adsorption Of Phmentioning

confidence: 99%

“…Thus, numerous studies have been devoted to the quantification and thermodynamic modeling of reversible metal cation adsorption on the cell wall of aquatic microorganisms [21][22][23][24]. Extensive research over past decades has provided a comprehensive picture of metal binding to cell walls of most model aquatic microorganisms, including autotrophic and heterotrophic bacteria and diatoms [25][26][27][28][29][30][31][32][33]. However, there is no study, to our knowledge, of AuNPs interaction with freshwater periphytic diatoms.…”

Section: Introductionmentioning

confidence: 99%

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Interaction of Freshwater Diatom with Gold Nanoparticles: Adsorption, Assimilation, and Stabilization by Cell Exometabolites

et al. 2018

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Abstract:The rising concern about the potential toxicity of synthetic gold nanoparticles (AuNPs) in aquatic environments requires a rigorous estimation of physico-chemical parameters of reactions between AuNPs and major freshwater microorganisms. This study addresses the interaction of 10-nm size, positively charged AuNPs with periphytic freshwater diatoms (Eolimna minima). The adsorption experiments on viable cells were performed in 10 mM NaCl and 5 mM NaCl + 5 mM NaHCO 3 solution at a variable pH (3-10), at an AuNPs concentration from 1 µg/L to 10,000 µg/L, and an exposure time from a few minutes to 55 days. Three types of experiments, adsorption as a function of time (kinetics), pH-dependent adsorption edge, and constant-pH "Langmuirian" type isotherms, were conducted. In addition, long-term interactions (days to weeks) of live diatoms (under light and in the darkness) were performed. The adsorption was maximal at a pH from 3 to 6 and sizably decreased at a pH of 6 to 10. Results of adsorption experiments were modeled using a second order kinetic model, a Linear Programming Model, Freundlich isotherm, and a ligand binding equation for one site competition. The adsorption of AuNPs(+) most likely occurred on negatively-charged surface sites of diatom cell walls such as carboxylates or phosphorylates, similar to previously studied metal cations. Under light exposure, the AuNPs were stabilized in aqueous solution in the presence of live cells, probably due to the production of exometabolites by diatoms. The adsorbed amount of AuNPs decreased after several days of reaction, suggesting some AuNPs desorption. In the darkness, the adsorption and assimilation were stronger than under light. Overall, the behavior of positively charged AuNPs at the diatom-aqueous solution interface is similar to that of metal cations, but the affinity of aqueous AuNPs to cell exometabolites is higher, which leads to the stabilization of nanoparticles in solution in the presence of diatoms and their exudates. During photosynthetic activity and the pH rising above 9 in the vicinity of diatom cells, the adsorption of AuNPs strongly decreases, which indicates a decreasing potential toxicity of AuNPs for photosynthesizing cells. The present study demonstrates the efficiency of a thermodynamic and kinetic approach for understanding gold nanoparticles interaction with aquatic freshwater peryphytic microorganisms.

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Modeling Approaches to Estimating Speciation and Interactions in Aqueous Systems

2013

Trace Metals in Aquatic Systems

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Cadmium and lead interaction with diatom surfaces: A combined thermodynamic and kinetic approach

Cited by 58 publications

References 49 publications

Diurnal variations of trace metals and heterotrophic bacterioplankton concentration in a small boreal lake of the White Sea basin

Diurnal variations of trace metals and heterotrophic bacterioplankton concentration in a small boreal lake of the White Sea basin

Interaction of Freshwater Diatom with Gold Nanoparticles: Adsorption, Assimilation, and Stabilization by Cell Exometabolites

Modeling Approaches to Estimating Speciation and Interactions in Aqueous Systems

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