A DGT Technique for Plutonium Bioavailability Measurements

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• 作者：Ruslan Cusnir ; Philipp Steinmann ; Fran莽ois Bochud ; Pascal Froidevaux
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：September 16, 2014
• 年：2014
• 卷：48
• 期：18
• 页码：10829-10834
• 全文大小：291K
• ISSN：1520-5851

文摘

The toxicity of heavy metals in natural waters is strongly dependent on the local chemical environment. Assessing the bioavailability of radionuclides predicts the toxic effects to aquatic biota. The technique of diffusive gradients in thin films (DGT) is largely exploited for bioavailability measurements of trace metals in waters. However, it has not been applied for plutonium speciation measurements yet. This study investigates the use of DGT technique for plutonium bioavailability measurements in chemically different environments. We used a diffusion cell to determine the diffusion coefficients (D) of plutonium in polyacrylamide (PAM) gel and found D in the range of 2.06鈥?.29 脳 10^鈥? cm² s^鈥?. It ranged between 1.10 and 2.03 脳 10^鈥? cm² s^鈥? in the presence of fulvic acid and in natural waters with low DOM. In the presence of 20 ppm of humic acid of an organic-rich soil, plutonium diffusion was hindered by a factor of 5, with a diffusion coefficient of 0.50 脳 10^鈥? cm² s^鈥?. We also tested commercially available DGT devices with Chelex resin for plutonium bioavailability measurements in laboratory conditions and the diffusion coefficients agreed with those from the diffusion cell experiments. These findings show that the DGT methodology can be used to investigate the bioaccumulation of the labile plutonium fraction in aquatic biota.