Calcium-deficient Hydroxyapatite as a Potential Sorbent for Strontium

• Sekine, Yurina

• Motokawa, Ryuhei

• Kozai, Naofumi

• Ohnuki, Toshihiko

• Matsumura, Daiju

• Tsuji, Takuya

• Kawasaki, Riku

• Akiyoshi, Kazunari

Abstract

A calcium (Ca)-deficient hydroxyapatite was investigated for its potential to remove Sr2+ from environmentally relevant water. We conducted sorption tests on solutions containing magnesium ion (Mg2+) and calcium ion (Ca2+) as competing cations at a strontium ion (Sr2+) concentration of 0.05 mmol/L. The Ca-deficient hydroxyapatite maintained a high Sr2+ sorption ratio of above 80% in the presence of Mg2+ and Ca2+ at the concentrations between 0.1 and 1.0 mmol/L, whereas the stoichiometric hydroxyapatite showed a lower ratio even in the presence of small amounts of Mg2+ and Ca2+ (72% for Mg2+ and 51% for Ca2+ at 0.1 mmol/L). For solutions with various Sr2+ concentrations between 0.01 and 10 mmol/L, Ca-deficient hydroxyapatite exhibited a higher Sr2+ sorption ratio than stoichiometric hydroxyapatite. The bonding states of Sr2+ on the Ca-deficient hydroxyapatite were evaluated by extended X-ray absorption fine structure measurements. The results indicated that there are specific sorption sites in Ca-deficient hydroxyapatite where Sr2+ is stably and preferentially immobilized.

Journal

• Scientific Reports

  Scientific Reports 7 2017-05-18

  Springer Nature

Keywords

• Ceramics
• Pollution remediation

Details

• CRID: 1050845760782104192
• NII Article ID: 120006368157
• ISSN: 20452322
• HANDLE: 2433/228138
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • CiNii Articles