6533b836fe1ef96bd12a1cc1
RESEARCH PRODUCT
Solubility of Zn(II) in Association with Calcium Silicate Hydrates in Alkaline Solutions
Michael KerstenC. A. Johnsonsubject
Aqueous solutionIon exchangeCoprecipitationInorganic chemistrychemistry.chemical_elementGeneral ChemistryZincchemistry.chemical_compoundchemistryCalcium silicateEnvironmental ChemistryCalcium silicate hydrateSolubilitySolid solutiondescription
The binding of Zn(II) to the cement mineral calcium silicate hydrate (CSH) was investigated in a well-defined laboratory system. CSH (Ca:Si = 1:1) was synthesized by coprecipitation with varying contents of Zn(II). Zn(II) was added in the proportions 0, 0.1, 1.0, 5.0, and 10% in exchange for Ca. The resulting CSH was characterized by X-ray diffraction. The solid phases were then equilibrated in aqueous suspensions, and the solubilities of Ca, Si, and of Zn(II) were determined as a function of pH and Zn(II) content in the solid phase. The solubility of Ca and Si in equilibrium with the CSH phases was in agreement with that predicted by thermodynamic calculations. Dissolved Zn(II) concentrations were below the solubility of ZnO and directly related to the concentration in the solid phase. It was postulated that solid solution is the mechanism by which Zn(II) is bound in the CSH matrix.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1999-05-15 | Environmental Science & Technology |