Research output: Contribution to journal › Article › peer-review
Long-term immobilisation of Cd2+ at the Tulul Al Hammam natural analogue site, central Jordan. / Sokol, Ella V.; Kokh, Svetlana N.; Khoury, Hani N. et al.
In: Applied Geochemistry, Vol. 70, 01.07.2016, p. 43-60.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Long-term immobilisation of Cd2+ at the Tulul Al Hammam natural analogue site, central Jordan
AU - Sokol, Ella V.
AU - Kokh, Svetlana N.
AU - Khoury, Hani N.
AU - Seryotkin, Yurii V.
AU - Goryainov, Sergei V.
PY - 2016/7/1
Y1 - 2016/7/1
N2 - The Tulul Al Hammam area in central Jordan is a natural analogue site where to study long-term Cd2+ retention during the weathering of Cd-enriched combustion-metamorphic marbles with clinker-like mineralogy. Natural Cd-rich portlandite (Ca0.67-0.45Cd0.33-0.55)[OH]2 was discovered and characterised by single-crystal XRD, SEM/EDS, and microprobe analyses, and Raman spectroscopy. The Ca[OH]2 - Cd[OH]2 solid solution ((Ca1-xCdx)[OH]2) is isostructural with Ca[OH]2 and β-Cd[OH]2 crystals in the CdI2-type of structure. Cd-rich portlandite is a common secondary phase in slightly altered massive marbles, where it replaces and rims single-crystals of the high-temperature precursor (Ca1-xCdx)O. The Cd:Ca molar ratios of (Ca1-xCdx)[OH]2 are inherited from the precursor phase (Ca1-xCdx)O. Reliable long-term immobilisation of Cd in (Ca1-xCdx)[OH]2 is assumed for pore water pH values from 10.5 up to 12 buffered by C-S-Hs formed mainly during spurrite hydration. The Tulul Al Hammam site may have some bearing on long-term Cd2+ retention in the concrete matrix.
AB - The Tulul Al Hammam area in central Jordan is a natural analogue site where to study long-term Cd2+ retention during the weathering of Cd-enriched combustion-metamorphic marbles with clinker-like mineralogy. Natural Cd-rich portlandite (Ca0.67-0.45Cd0.33-0.55)[OH]2 was discovered and characterised by single-crystal XRD, SEM/EDS, and microprobe analyses, and Raman spectroscopy. The Ca[OH]2 - Cd[OH]2 solid solution ((Ca1-xCdx)[OH]2) is isostructural with Ca[OH]2 and β-Cd[OH]2 crystals in the CdI2-type of structure. Cd-rich portlandite is a common secondary phase in slightly altered massive marbles, where it replaces and rims single-crystals of the high-temperature precursor (Ca1-xCdx)O. The Cd:Ca molar ratios of (Ca1-xCdx)[OH]2 are inherited from the precursor phase (Ca1-xCdx)O. Reliable long-term immobilisation of Cd in (Ca1-xCdx)[OH]2 is assumed for pore water pH values from 10.5 up to 12 buffered by C-S-Hs formed mainly during spurrite hydration. The Tulul Al Hammam site may have some bearing on long-term Cd2+ retention in the concrete matrix.
KW - Cd-rich portlandite
KW - Cement
KW - Central Jordan
KW - Long-term Cd retention
KW - Natural analogue
KW - Waste management
UR - http://www.scopus.com/inward/record.url?scp=84971290742&partnerID=8YFLogxK
U2 - 10.1016/j.apgeochem.2016.05.002
DO - 10.1016/j.apgeochem.2016.05.002
M3 - Article
AN - SCOPUS:84971290742
VL - 70
SP - 43
EP - 60
JO - Applied Geochemistry
JF - Applied Geochemistry
SN - 0883-2927
ER -
ID: 25760927