Title :

Heterogeneous microchemistry between CdSO₄ and CaCO₃ particles under humidity and liquid water

Author(s) :

Falgayrac, G. [Auteur correspondant]
Marrow Adiposity & Bone Lab - Adiposité Médullaire et Os - ULR 4490 [MABLab]
Sobanska, S. [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 [LASIRE]
Brémard, C. [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 [LASIRE]

Journal title :

Journal of hazardous materials

Pages :

415 - 423

Publisher :

Elsevier

Publication date :

2013

ISSN :

0304-3894

HAL domain(s) :

Chimie/Chimie théorique et/ou physique

English abstract : [en]

Laboratory experiments using in situ Raman imaging combined with ex situ TOF-S-SIMS demonstrate the behavior of CdSO₄*8/3H₂O microparticles in contact with { 1014 } CaCO₃ (calcite) surface ...
Show more >Laboratory experiments using in situ Raman imaging combined with ex situ TOF-S-SIMS demonstrate the behavior of CdSO₄*8/3H₂O microparticles in contact with { 1014 } CaCO₃ (calcite) surface under three different experimental conditions representative of unpolluted atmosphere. The contact of CdSO₄*8/3H₂O particles with CaCO₃ surface in humid air (RH ∼ 40-80%) does not induce any chemical reaction. In contrast, the condensation of a water drop on CdSO₄*8/3H₂O/CaCO₃ interface causes the free dissolution of CdSO₄*8/3H₂O particle in the drop. A CdSO₄*8/3H₂O microcrystal is reformed after gentle drying with a CdSO₄*H₂O coating of the CaCO₃ surface. The TOF-S-SIMS image of the CaCO₃ surface provides evidence of a thin layer corresponding probably to insoluble coating of CdCO₃ (otavite) or Cd_xCa₁−_xCO₃ solid solution at the liquid-solid interface. This layer armours the CaCO₃ from further dissolution and stops the reaction. The deposition of CdSO₄*8/3H₂O particle in water drop previously in contact with CaCO₃ for a long time generates CdCO₃ small rhombohedral crystals while gentle drying provokes the crystallization of bar shape crystals of CaSO₄*2H₂O (gypsum). These laboratory results provide valuable chemical prediction for a possible fate of cadmium rich particles emitted in the atmosphere and thus, can contribute to realistic assessment of human exposure to Cd hazard.Show less >

Language :

Anglais

Popular science :

Non

Collections :

• Marrow Adiposity & Bone Lab (MABLab) - ULR 4490

Source :

Harvested from HAL