GEOC 64 |
| Liping Weng, Willem H van Riemsdijk, Erwin Temminghoff, and Erwin Kalis. Department of Soil Quality, Wageningen University, Dreijenplein 10, Wageningen, Netherlands |
| The FIAM model and the BLM model require knowledge about the free metal ion concentration. The free metal ion concentration in many surface waters and pore waters is very low because metals bind strongly to e.g. NOM. Measuring free metal ion concentration in the field is extremely difficult. We have recently developed a new passive field cell, based on a Donnan membrane Technique (DMT), which can be used to derive the free metal ion concentration of cations in natural waters. The operation of the new cell has been extensively tested using well defined synthetic solutions with known metal ion activities. In order to get more insight in the functioning of the technique we have also done numerical simulations on the reactive diffusive transport of metal ions over the membrane. The cell has been used in the field (lake Greiffen and river Rhine), to measure the activities of free Cu, Cd, Zn, and Pb. |
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Chemistry of Metals in Terrestrial and Aquatic Systems
8:00 AM-11:30 AM, Tuesday, March 30, 2004 Marriott -- Marquis NE, Oral
Division of Geochemistry |