Author
G. A. van den Berg
Bio: G. A. van den Berg is an academic researcher from Ontario Ministry of Transportation. The author has contributed to research in topics: Trace metal & Sulfide. The author has an hindex of 4, co-authored 4 publications receiving 230 citations.
Topics: Trace metal, Sulfide, Manganese, Dissolution, Pore water pressure
Papers
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TL;DR: Deployment of a combined probe in marine sediment revealed simultaneous remobilisation of metals and sulfide at the same location andSolubility calculations indicated that some precipitation of amorphous FeS was probably occurring at the maxima in sulfide concentrations.
96 citations
TL;DR: Pore water and sediment analyses indicate a shift in trace metal speciation from oxide-bound to sulfide-bound over the upper 20 cm of the sediment, and sensitivity analyses show that increased bioturbation and sulfate availability, expected upon restoration of estuarine conditions in the lake, should increase the sulfide bound fractions of Zn and Ni in the sediments.
93 citations
TL;DR: Observations suggest that trace metals are not immediately bound in an insoluble, inert form when they are in contact with sulphide, which has consequences for modelling metal processes in sediment, as well as for uptake by some biota.
44 citations
TL;DR: In this article, the potential release of metals from anoxic sediments exposed to oxygen was investigated by using a synthetic preparation of metal sulphides dominated by solid phase FeS, which had a pH of 6.4.
Abstract: The potential release of metals from anoxic sediments exposed to oxygen was investigated by using a synthetic preparation of metal sulphides dominated by solid phase FeS. The technique of DGT (diffusive gradients in thin-films) was used to measure sulphide and Fe, Mn and Ni in the anoxic metal-sulphide slurry, which had a pH of 6.4. Speciation calculations based on these data showed there was moderate supersaturation with respect to amorphous FeS in the solution phase. Measurements made using DGT with a range of diffusion layer thicknesses showed that when Fe, Mn and Ni are removed from solution there is fairly rapid (minutes) release from the solid phase, that is reasonably well sustained. This presumed desorptive release will be responsible for elevated concentrations of some metals in solution when sediments are resuspended. Oxidation of the slurry by bubbling with air rapidly (hours) removed Fe, Mn and Ni from the pore water solution. While Fe concentrations in solution remained low after the removal, Mn and Ni were transiently released. These results were consistent with initial rapid oxidation of Fe(II) to oxyhydroxides, which remove Mn(II) and Ni by adsorption. The slower oxidation of FeS then releases Mn and Ni, but these too are eventually removed by adsorption to iron oxyhydroxides. These data suggest that oxidation of metal sulphides will contribute to the release of metals from sediment disturbed by dredging or remedial aeration, but it is likely to be short lived, with complete removal within a day.
15 citations
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TL;DR: A recent review as mentioned in this paper discusses the significance and future direction of microniche studies by considering, exclusively, data obtained on a sub-mm scale that provide significant evidence for the existence and properties of micro-organisms.
215 citations
TL;DR: In this study, a diffusive gradients in thin films (DGT) technique was developed for the high-resolution simultaneous measurements of dissolved reactive phosphorus (DRP) and dissolved sulfide and the good performance implies that there is a great potential for the development of new DGT techniques capable of simultaneous measurement of more analytes.
Abstract: The reassessments of environmental processes in sediments rely upon capturing the heterogeneous features of elements at a small scale and at the same location. In this study, a diffusive gradients in thin films (DGT) technique was developed for the high-resolution simultaneous measurements of dissolved reactive phosphorus (DRP) and dissolved sulfide. A new binding gel was used in this DGT technique, which was prepared by incorporating AgI particles into the zirconium oxide binding gel previously used in the DGT measurement of DRP. The concentrations of the DRP and sulfide loaded into the binding gel were determined by a routine procedure and a computer-imaging densitometry (CID) technique, respectively. The performance of this DGT technique was tested under laboratory conditions and applied to in situ measurements in sediments of a shallow lake. Simultaneous release of DRP and dissolved sulfide was observed in a sulfide microniche with a diameter of ∼3 mm and in locally aggregated zones with a length over...
143 citations
TL;DR: In this paper, solid phase and pore water chemical data collected in a sediment of the Haringvliet Lake are interpreted using a multi-component reactive transport model to assess the present-day biogeochemical dynamics in the sediment, and to forecast possible changes in organic carbon mineralization pathways and associated redox reactions upon salinization of the bottom waters.
128 citations
TL;DR: In this article, three sediment cores were collected in the Scheldt, Lys and Spiere canals, which drain a highly populated and industrialized area in Western Europe, and the speciation and the distribution of trace metals in pore waters and sediment particles were assessed through a combination of computational and experimental techniques.
112 citations
TL;DR: Significantly positive correlations of labile P were observed switching from between labile Fe and labile S in sediments, suggesting a significant change in original Fe-coupled dynamics of P under algae decomposition.
105 citations