NDLI: Local structure of Th complexes on montmorillonite clay mineral determined by extended X-ray absorption fine structure (EXAFS) spectroscopy*

Please wait, while we are loading the content...

Local structure of Th complexes on montmorillonite clay mineral determined by extended X-ray absorption fine structure (EXAFS) spectroscopy*

Content Provider	Semantic Scholar
Author	Dähn, Rainer Scheidegger, André M. Manceau, Alain Baeyens, B. Bradbury, Michael H.
Copyright Year	2001
Abstract	The research at the Waste Management Laboratory, PSI, concentrates on the understanding of safety relevant mechanisms and processes that govern the release of radionuclides from waste matrices, and their transport through engineered barrier systems and the surrounding geosphere. For this reason, detailed sorption studies of radionuclides in clay and cement systems are conducted. The studies are combined with extended X-ray absorption fine structure (EXAFS) spectroscopy measurements in order to understand the sorption mechanisms on an atomic level. In this manuscript, a case study of Th(IV) uptake on montmorillonite is presented. EXAFS samples were prepared by incubating a montmorillonite suspension with Th for 7 days at pH = 5 (Thinitial: 4.3 x 10 -5 - 4 x 10 -4 M). The resulting Th loadings on the clay varied between 14 and 166 µmol/g. LIII-Th EXAFS spectra of Th treated montmorillonite were measured at the Rossendorfer Beamline at the European Synchrotron Radiation Facility. Data analysis revealed the presence of two O shells at 2.27 A and 2.45 A in all samples. The spectra at low Th uptake suggest the presence of Si/Al and Th backscattering atoms at distances of 3.85 A and 3.77 A respectively. The presence of a Th-Si/Al backscattering pair suggests that Th is bound to Si tetrahedra by a double corner-sharing manner. At higher Th uptake, however, the spectrum shows a strong similarity with the spectrum of amorphous Th(OH)4 and suggests that Th is predominately present as a newly formed Th(OH)4-like phase.
File Format	PDF HTM / HTML
Alternate Webpage(s)	http://www.hzdr.de/ROBL/Annual/JB00_con6.pdf
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article

Central Library (ISO-9001:2015 Certified)
Indian Institute of Technology Kharagpur
Kharagpur, West Bengal, India | PIN - 721302

See location in the Map
03222 282435
Mail: support@ndl.gov.in

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in