Zn Isotope Fractionation during Sorption onto Kaolinite - INSU - Institut national des sciences de l'Univers Access content directly
Journal Articles Environmental Science and Technology Year : 2016

Zn Isotope Fractionation during Sorption onto Kaolinite


In this study, we quantify zinc isotope fractionation during its sorption onto kaolinite, by performing experiments under various pH, ionic strength, and total Zn concentrations. A systematic enrichment in heavy Zn isotopes on the surface of kaolinite was measured, with Delta Zn-66(adsorbed-solution) ranging from 0.11 parts per thousand at low pH and low ionic strength to 0.49 parts per thousand at high pH and high ionic strength. Both the measured Zn concentration and its isotopic ratio are correctly described using a thermodynamic sorption model that considers two binding sites: external basal surfaces and edge sites. Based on this modeling approach, two distinct Zn isotopic fractionation factors were calculated: Delta Zn-66(adsorbed-solution) = 0.18 +/- 0.06 parts per thousand for ion exchange onto basal sites, and Delta Zn-66(adsorbed-solution) = 0.49 +/- 0.06 parts per thousand for specific complexation onto edge sites. These two distinct factors indicate that Zn isotope fractionation is dominantly controlled by the chemical composition of the solution (pH, ionic strength)
No file

Dates and versions

insu-02872487 , version 1 (17-06-2020)



Damien Guinoiseau, Alexandre Gelabert, Julien Moureau, Pascale Louvat, Marc Benedetti. Zn Isotope Fractionation during Sorption onto Kaolinite. Environmental Science and Technology, 2016, 50 (4), pp.1844-1852. ⟨10.1021/acs.est.5b05347⟩. ⟨insu-02872487⟩
19 View
0 Download



Gmail Facebook X LinkedIn More