Kinetic Studies of Ni Organic Complexes Using Diffusive Gradients in Thin Films (DGT) with Double Binding Layers and a Dynamic Numerical Model

2012 ◽  
Vol 47 (1) ◽  
pp. 463-470 ◽  
Author(s):  
M. R. Shafaei Arvajeh ◽  
N. Lehto ◽  
Ø. A. Garmo ◽  
H. Zhang
Keyword(s):  
Thin Films ◽  
Numerical Model ◽  
Kinetic Studies ◽  
Organic Complexes ◽  
Diffusive Gradients

scholarly journals Progress in understanding the use of diffusive gradients in thin films (DGT) – back to basics

2012 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
William Davison ◽  
Hao Zhang
Keyword(s):  
Thin Films ◽  
Natural Waters ◽  
Kinetic Studies ◽  
Simple Equation ◽  
Charge Effects ◽  
The Past ◽  
Soils And Sediments ◽  
Rate Of Reaction ◽  
Simple Equations ◽  
Diffusive Gradients

Environmental contextIt is now nearly 20 years since the introduction of the technique of diffusive gradients in thin films, which can provide information on solute concentrations and dynamics in sediments, soils and water. The interpretation of these measurements in terms of concentrations relies on simple equations and associated assumptions. This review examines how well they have stood the test of time. AbstractDiffusive gradients in thin films (DGT) is now widely used to measure a range of determinands in waters, soils and sediments. In most cases the mass accumulated is interpreted in terms of a labile form of the component being measured using a simple equation that applies to steady-state conditions. During the past decade several publications have revealed phenomena that question some of the assumptions necessary for use of the simple equation. This review systematically examines the available evidence relating to appropriate geometry, possible charge effects, binding of solutes and ligands to the diffusive gel and filter, the rate of reaction with the binding layer, the effects of solution complexation and kinetic limitation, necessary time for deployment and the measurement of nanoparticles. DGT emerges as a robust monitoring tool for labile components in solution. Although there is evidence, for some conditions, of binding of metals and, more moderately, humic substances to the diffusive gel and filter membrane, this is unlikely to affect DGT measurement in natural waters for deployment times exceeding a few days. Detailed speciation and kinetic studies require a more thorough interpretation of the mass accumulated by DGT. A coherent theory has emerged for relatively simple solutions, but systems with complex heterogeneous ligands, as is the case for natural waters, are challenging. The size discrimination of DGT is still poorly known. Systematic measurements with well characterised nanoparticles are required to define the distribution of pore sizes in the gels and to establish the contribution of natural colloids to the DGT measurement.

Localised mobilisation of metals, as measured by diffusive gradients in thin-films, in soil historically treated with sewage sludge

Chemosphere ◽  
2013 ◽  
Vol 90 (2) ◽  
pp. 464-470 ◽  
Author(s):  
Jun Luo ◽  
Hao Zhang ◽  
William Davison ◽  
Ronald G. McLaren ◽  
Lynne M. Clucas ◽  
...  
Keyword(s):  
Thin Films ◽  
Sewage Sludge ◽  
Diffusive Gradients

scholarly journals Diffusive gradients in thin films: devices, materials and applications

2018 ◽  
Vol 17 (2) ◽  
pp. 801-831 ◽  
Author(s):  
Cai Li ◽  
Shiming Ding ◽  
Liyuan Yang ◽  
Yan Wang ◽  
Mingyi Ren ◽  
...  
Keyword(s):  
Thin Films ◽  
Diffusive Gradients

In situ measurement of perfluoroalkyl substances in aquatic systems using diffusive gradients in thin-films technique

2018 ◽  
Vol 144 ◽  
pp. 162-171 ◽  
Author(s):  
Dong-Xing Guan ◽  
Ya-Qing Li ◽  
Nan-Yang Yu ◽  
Guang-Hui Yu ◽  
Si Wei ◽  
...  
Keyword(s):  
Thin Films ◽  
In Situ Measurement ◽  
Aquatic Systems ◽  
Perfluoroalkyl Substances ◽  
Diffusive Gradients
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