Zn and Cd retention by a calcareous fluvio-glacial deposit in the presence of Pb: experiments, modelling and microanalysis
We studied the simultaneous transfer of Zn, Cd and Pb in a calcareous substrate, extracted from a fluvio- glacial deposit that is used to infiltrate stormwater. Laboratory column experiments showed that Pb retention was the strongest, as expected. However, Zn and Cd retentions were almost equal, in disagreement with conventional modelling assumptions. Investigations based on PHREEQC reactive modelling and both scanning electron microscopy (SEM) and PIXE/RBS analysis (nuclear microprobe) proved that Zn and Cd did not precipitate separately as smithsonite and otavite as usually observed under these experimental conditions. These investigations point at a surface substitution process in which Ca is successively replaced by metals such as Zn and Cd on surface sites, followed by diffusion of these metals into the lattice of the calcareous particles.
calcareous deposit PIXE RBS SEM PHREEQC reactive transfer
Laurent Lassabatere Laureline Fevrier Lorenzo Spadini Cecile Delolme Caroline Raepsaet
LCPC, Division for Water, Route de Bouaye, Bouguenais, 44381 (Cedex), France IRSN, DEI/SECRE/LRE- bid 186, CeCadarache, BP3, Saint Paul lez Durance, 13115 (Cedex), France LGIT, Maison des G osciences, Rue de la Piscine, Saint Martin DH res, 38400, France LSE, ENTPE, Rue Maurice Audin, Vaulx en Velin, 69518 (Cedex), France CEA Saclay, DSM/DRECAM/LPS, Gif sur Yvette, 91191 (Cedex), France
国际会议
第九届痕量元素生物地球化学国际会议(9th International Conference on the Biogeochemistry of Trace Elements)
北京
英文
334-335
2007-07-15（万方平台首次上网日期，不代表论文的发表时间）