Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

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Model predictions of metal speciation in freshwaters compared to measurements by in situ techniques
Unsworth, E.R. ; Warnken, K.W. ; Zhang, H. ; Davison, W. ; Black, F. ; Buffle, J. ; Cao, J. ; Cleven, R.F.M.J. ; Galceran, J. ; Gunkel, P. ; Kalis, E.J.J. ; Kistler, D. ; Leeuwen, H.P. van; Martin, M. ; Noel, S. ; Nur, Y. ; Odzak, N. ; Pauy, J. ; Riemsdijk, W.H. van; Sigg, L. ; Temminghoff, E.J.M. ; Tercier-Waeber, M.L. ; Topperwien, S. ; Town, R.M. ; Weng, L.P. ; Xue, Hanbin - \ 2006
Environmental Science and Technology 40 (2006)6. - ISSN 0013-936X - p. 1942 - 1949.
donnan membrane technique - permeation liquid-membrane - dissolved organic-matter - biotic ligand model - humic substances - natural-waters - ion-binding - thin-films - diffusive gradients - acute toxicity
Measurements of trace metal species in situ in a softwater river, a hardwater lake, and a hardwater stream were compared to the equilibrium distribution of species calculated using two models, WHAM 6, incorporating humic ion binding model VI and visual MINTED incorporating NICA-Donnan. Diffusive gradients in thin films (DGT) and voltammetry at a gel integrated microelectrode (GIME) were used to estimate dynamic species that are both labile and mobile. The Donnan membrane technique (DMT) and hollow fiber permeation liquid membrane (HFPLM) were used to measure free ion activities. Predictions of dominant metal species using the two models agreed reasonably well, even when colloidal oxide components were considered. Concentrations derived using GIME were generally lower than those from DGT, consistent with calculations of the lability criteria that take into account the smaller time window available for the flux to GIME. Model predictions of free ion activities generally did not agree with measurements, highlighting the need for further work and difficulties in obtaining appropriate input data
Comparison of analytical techniques for dynamic trace metal speciation in natural freshwaters
Sigg, L. ; Black, F. ; Buffle, J. ; Cao, J. ; Cleven, R. ; Davison, W. ; Galceran, J. ; Gunkel, P. ; Kalis, E.J.J. ; Kistler, D. ; Martin, M. ; Noel, S. ; Nur, Y. ; Odzak, N. ; Puy, J. ; Riemsdijk, W.H. van; Temminghoff, E.J.M. ; Tercier-Waeber, M.L. ; Toepperwien, S. ; Town, R.M. ; Unsworth, E.R. ; Warnken, K.W. ; Weng, L.P. ; Xue, H.B. ; Zhang, H. - \ 2006
Environmental Science and Technology 40 (2006)6. - ISSN 0013-936X - p. 1934 - 1941.
permeation liquid-membrane - in-situ measurements - voltammetry cle-adsv - biotic ligand model - stripping chronopotentiometry - thin-films - microelectrode - bioavailability - complexes - systems
Several techniques for speciation analysis of Cu, Zn, Cd, Pb, and Ni are used in freshwater systems and compared with respect to their performance and to the metal species detected. The analytical techniques comprise the following: (i) diffusion gradients in thin-film gels (DGT); (ii) gel integrated microelectrodes combined to voltammetric in situ profiling system (GIME-VIP); (iii) stripping chronopotentiometry (SCP); (iv) flow-through and hollow fiber permeation liquid membranes (FTPLM and HFPLM); (v) Donnan membrane technique (DMT); (vi) competitive ligand-exchange/stripping voltammetry (CLE-SV). All methods could be used both under hardwater and under softwater conditions, although in some cases problems with detection limits were encountered at the low total concentrations. The detected Cu, Cd, and Pb concentrations decreased in the order DGT ¿ GIME-VIP ¿ FTPLM ¿ HFPLM ¿ DMT (> CLE-SV for Cd), detected Zn decreased as DGT ¿ GIME-VIP and Ni as DGT > DMT, in agreement with the known dynamic features of these techniques. Techniques involving in situ measurements (GIME-VIP) or in situ exposure (DGT, DMT, and HFPLM) appear to be appropriate in avoiding artifacts which may occur during sampling and sample handling
Dynamic speciation analysis and bioavailability of metals in aquatic systems
Leeuwen, H.P. van; Town, R.M. ; Buffle, J. ; Cleven, R.F.M.J. ; Davison, W. ; Puy, J. ; Riemsdijk, W.H. van; Sigg, L. - \ 2005
Environmental Science and Technology 39 (2005)22. - ISSN 0013-936X - p. 8545 - 8556.
chemische speciatie - metalen - risicoschatting - biologische beschikbaarheid - waterbodems - chemical speciation - metals - risk assessment - bioavailability - water bottoms - in-situ measurements - deposition potential sscp - anodic-stripping voltammetry - permeation liquid-membrane - association dissociation kinetics - integrated microelectrode arrays - ion-selective electrodes - lower detection limit - biotic ligand model - natural-w
Dynamic metal speciation analysis in aquatic ecosystems is emerging as a powerful basis for development of predictions of bioavailability and reliable risk assessment strategies. A given speciation sensor is characterized by an effective time scale or kinetic window that defines the measurable metal species via their labilities. Here we review the current state of the art for the theory and application of dynamic speciation sensors. We show that a common dynamic interpretation framework, based on rigorous flux expressions incorporating the relevant diffusion and reaction steps, is applicable for a suite of sensors that span a range of time scales. Interpolation from a kinetic spectrum of speciation data is proposed as a practical strategy for addressing questions of bioavailability. Case studies illustrate the practical significance of knowledge on the dynamic features of metal complex species in relation to biouptake, and highlight the limitations of equilibrium-based models.
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