TY - JOUR
T1 - Adsorption characteristics of Cs+ on biogenic birnessite
AU - Sasaki, Keiko
AU - Yu, Qianqian
AU - Momoki, Taichi
AU - Kaseyama, Takuya
N1 - Funding Information:
Financial support was provided to KS by the Funding Program for Next Generation of World-Leading Researchers ( GR078 ) for the Japan Society for Promotion of Science (JSPS). XAFS/EXAFS spectra were collected at SAGA Light Source Kyushu Synchrotron Light Source Center (Proposal No. 2012IIK017). The authors acknowledge Dr. Yudzuru Inoue for collecting XFAS spectra.
Publisher Copyright:
© 2014 Elsevier B.V.
PY - 2014/11/1
Y1 - 2014/11/1
N2 - Adsorption of Cs+ on biogenic birnessite was investigated and compared with (ad)sorption of other heavy metals and also with (ad)sorption on chemically synthesized birnessite. The adsorption density of Cs+ on biogenic birnessite was smaller than that on chemically synthesized birnessite; however, the (ad)sorption densities of Co2+ and Ni2+ on biogenic birnessite were larger than on chemically synthesized birnessite. These phenomena can be interpreted by considering the distinctive nano-structure of biogenic birnessite, which is not only poorly crystalline and includes organic matter but also according to EXAFS contains a greater proportion of vacant central metal sites than is found in synthetic birnessite. Adsorbed Cs+ ions on both birnessites were mainly in the form of outer sphere complexes, which cannot easily occupy vacant central metal sites in biogenic birnessite. Biogenic birnessite has a greater specific surface area and more fine pores than synthetic birnessite, but these factors do not necessarily lead to more adsorption sites for Cs+ ions.
AB - Adsorption of Cs+ on biogenic birnessite was investigated and compared with (ad)sorption of other heavy metals and also with (ad)sorption on chemically synthesized birnessite. The adsorption density of Cs+ on biogenic birnessite was smaller than that on chemically synthesized birnessite; however, the (ad)sorption densities of Co2+ and Ni2+ on biogenic birnessite were larger than on chemically synthesized birnessite. These phenomena can be interpreted by considering the distinctive nano-structure of biogenic birnessite, which is not only poorly crystalline and includes organic matter but also according to EXAFS contains a greater proportion of vacant central metal sites than is found in synthetic birnessite. Adsorbed Cs+ ions on both birnessites were mainly in the form of outer sphere complexes, which cannot easily occupy vacant central metal sites in biogenic birnessite. Biogenic birnessite has a greater specific surface area and more fine pores than synthetic birnessite, but these factors do not necessarily lead to more adsorption sites for Cs+ ions.
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U2 - 10.1016/j.clay.2014.06.028
DO - 10.1016/j.clay.2014.06.028
M3 - Article
AN - SCOPUS:84908363361
SN - 0169-1317
VL - 101
SP - 23
EP - 29
JO - Applied Clay Science
JF - Applied Clay Science
ER -