Eine Versuchsdeponie für verfestigte Rückstände aus der Rauchgasreinigung von Kehrichtverbrennungsanlagen – Teil 1

Ochs, Michael; Stäubli, Beat; Wanner, Hans

doi:10.37307/j.1863-9763.1999.04.02

Cited by 2 publications

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Cement is commonly used worldwide for the stabilization and solidification of waste materials containing heavy metal species (1). However, due to their high heavy metal content, these cement-based waste materials remain a potential environmental risk over centuries (2)(3)(4), whereas the emissions may last thousands of years. Thus, the long-term leachability of the cement-stabilized residues is the most important factor in the assessment of the potential hazards associated with their landfilling (5).…”

Section: Introductionmentioning

confidence: 99%

Sorption Mechanisms of Zinc to Calcium Silicate Hydrate: X-ray Absorption Fine Structure (XAFS) Investigation

Ziegler

Scheidegger

Johnson

et al. 2001

Environ. Sci. Technol.

View full text Add to dashboard Cite

In this study, X-ray absorption fine structure (XAFS) spectroscopy has been used to further elucidate the binding mechanisms of Zn(II) to calcium silicate hydrate (C-S-H), the quantitatively most important cement mineral. Such knowledge is essential for the assessment of the longterm behavior of cement-stabilized waste materials. XAFS spectra of the Zn(II) equilibrated with C-S-H(I) for up to 28 days are best modeled by tetrahedral coordination of Zn(II) by four O atoms in the first atomic shell. Beyond the first coordination shell, data analysis of more highly concentrated samples suggests the presence of two distinct Zn distances and possibly the presence of an Si shell. On the basis of the comparison with a set of reference compounds, this coordination environment can be reasonably related to the structure of hemimorphite, a naturally occurring zinc silicate, and/or the presence of gamma-Zn(OH)2. At the lowest Zn uptake, the above fitting approach failed and data could be described best with a Zn-Si and a Zn-Ca shell. Previous work has been able to show that Zn(II) diffuses into the C-S-H(I) particles and does not form discrete precipitates, so the findings appear to confirm the incorporation of Zn(II) in the interlayer of C-S-H(I).

show abstract

Section: Introductionmentioning

confidence: 99%