Trace Metal Measurements in Low Ionic Strength Synthetic Solutions by Diffusive Gradients in Thin Films

2005 ◽  
Vol 77 (17) ◽  
pp. 5440-5446 ◽  
Author(s):  
Kent W. Warnken ◽  
Hao Zhang ◽  
William Davison
Keyword(s):  
Thin Films ◽  
Ionic Strength ◽  
Trace Metal ◽  
Low Ionic Strength ◽  
Diffusive Gradients

Response of diffusive equilibrium in thin films (DET) and diffusive gradients in thin films (DGT) trace metal profiles in sediments to phytodetritus mineralisation

2012 ◽  
Vol 9 (1) ◽  
pp. 41 ◽  
Author(s):  
Yue Gao ◽  
Martine Leermakers ◽  
Annelies Pede ◽  
Aurelie Magnier ◽  
Koen Sabbe ◽  
...  
Keyword(s):  
Thin Films ◽  
Trace Metals ◽  
Trace Metal ◽  
Phytoplankton Bloom ◽  
Marine Ecosystem ◽  
Trace Metal Concentration ◽  
Water Interface ◽  
Overlying Water ◽  
Study Laboratory ◽  
Diffusive Gradients

Environmental contextContaminated sediments can have a large and lasting effect on marine ecosystems. It was discovered that significant amounts of pollutants, especially arsenic, were released from contaminated sediments during a phytoplankton bloom in the Belgian Continental Zone. Once released to the water column, these pollutants can accumulate up marine food chains and be a source of contaminants to humans. AbstractField data from the Belgian Continental Zone showed elevated trace metal concentrations at the sediment–water interface after the occurrence of a phytoplankton bloom. In the present study, laboratory incubation experiments were used to investigate the effect of the phytodetritus remineralisation process on the release of trace metals from contaminated muddy sediments. This remineralisation process was followed by the measurement of chlorophyll-a and dissolved organic carbon levels in the top sediment layers. Two gel techniques, diffusive equilibrium in thin films (DET) and diffusive gradients in thin films (DGT), were used to assess vertical metal profiles in the sediment pore waters and to calculate the metal effluxes. These metal effluxes compared very well with the trace metal concentration variations in the overlying water of the sediment. Much higher effluxes of Mn, Co and As were observed after 2 days of incubation in the microcosms which received additions of phytodetritus. This trend gradually decreased after 7 days of incubation, suggesting that the elevated efflux of trace metals was proportional to the quantity of phytodetritus mineralised at the sediment–water interface. The release of large amounts of toxic elements from the sediments after phytoplankton blooms can therefore potentially affect the marine ecosystem in the Belgian Continental Zone.

Predicting trace metal bioavailability to chironomids in sediments by diffusive gradients in thin films

2018 ◽  
Vol 636 ◽  
pp. 134-141 ◽  
Author(s):  
Yan He ◽  
Changsheng Guo ◽  
Jiapei Lv ◽  
Song Hou ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Thin Films ◽  
Trace Metal ◽  
Metal Bioavailability ◽  
Diffusive Gradients

scholarly journals Assessment of trace metal binding kinetics in the resin phase of diffusive gradients in thin films

2012 ◽  
Vol 717 ◽  
pp. 143-150 ◽  
Author(s):  
Jacqueline L. Levy ◽  
Hao Zhang ◽  
William Davison ◽  
Jaume Puy ◽  
Josep Galceran
Keyword(s):  
Thin Films ◽  
Trace Metal ◽  
Metal Binding ◽  
Binding Kinetics ◽  
Resin Phase ◽  
Diffusive Gradients

scholarly journals Adhesion of Pseudomonas fluorescens(ATCC 17552) to Nonpolarized and Polarized Thin Films of Gold

2001 ◽  
Vol 67 (7) ◽  
pp. 3188-3194 ◽  
Author(s):  
J. P. Busalmen ◽  
S. R. de S�nchez
Keyword(s):  
Thin Films ◽  
Ionic Strength ◽  
Pseudomonas Fluorescens ◽  
Theoretical Calculations ◽  
Gold Surface ◽  
High Ionic Strength ◽  
Reversible Adhesion ◽  
Controlled Flow ◽  
Low Ionic Strength

ABSTRACT The adhesion of Pseudomonas fluorescens (ATCC 17552) to nonpolarized and negatively polarized thin films of gold was studied in situ by contrast microscopy using a thin-film electrochemical flow cell. The influence of the electrochemical potential was evaluated at two different ionic strengths (0.01 and 0.1 M NaCl; pH 7) under controlled flow. Adhesion to nonpolarized gold surfaces readily increased with the time of exposition at both ionic-strength values. At negative potentials (−0.2 and −0.5 V [Ag/AgCl-KCl saturated {sat.}]), on the other hand, bacterial adhesion was strongly inhibited. At 0.01 M NaCl, the inhibition was almost total at both negative potentials, whereas at 0.1 M NaCl the inhibition was proportional to the magnitude of the potential, being almost total at −0.5 V. The existence of reversible adhesion was investigated by carrying out experiments under stagnant conditions. Reversible adhesion was observed only at potential values very close to the potential of zero charge of the gold surface (0.0 V [Ag/AgCl-KCl sat.]) at a high ionic strength (0.1 M NaCl). Theoretical calculations of the Derjaguin-Landau-Verwey-Overbeek (DLVO) interaction energy for the bacteria-gold interaction were in good agreement with experimental results at low ionic strength (0.01 M). At high ionic strength (0.1 M), deviations from DLVO behavior related to the participation of specific interactions were observed, when surfaces were polarized to negative potentials.

scholarly journals Characterization of sorption gels used for determination of mercury in aquatic environment by diffusive gradients in thin films technique

2010 ◽  
Vol 8 (5) ◽  
pp. 1105-1109 ◽  
Author(s):  
Pavel Diviš ◽  
Roman Szkandera ◽  
Hana Dočekalová
Keyword(s):  
Thin Films ◽  
Standard Deviation ◽  
Ionic Strength ◽  
Aquatic Environment ◽  
Chelex 100 ◽  
Natural Ligands ◽  
Diffusive Gradients ◽  
Influence Of Ph

AbstractThe influence of pH, ionic strength and selected natural ligands on the measurement of mercury by the diffusive gradients in thin films technique (DGT) using recently introduced sorption gels was determined. Sorption gels containing Chelex 100, Spheron-Thiol, Duolite GT73 and modified Iontosorb AV resins were investigated, with the sorption capacity determined for all used sorption gels. The minimum DGT measurable concentrations were calculated from 3 times the standard deviation of mercury amount in unexposed sorption gels.

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