Influence of silicate on the structural memory effect of layered double hydroxides for the immobilization of selenium

Quanzhi Tian, Binglin Guo, Keiko Sasaki

研究成果: Contribution to journalArticle査読

2 被引用数 (Scopus)

抄録

The influence of silicate on the structural memory effect of layered double hydroxides (LDHs) has been rarely reported. In this study, five kinds of calcined LDHs (CLDHs) were synthesized and used as adsorbents for the sorption of selenium with or without silicate, under the initial pH 10 and 13, respectively, characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), infrared spectroscopy (IR), nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), and N2 adsorption-desorption isotherm. The results indicated that silicate can significantly affect the phase transformation of CLDHs, and the sorption amounts of selenite and selenate dramatically decreased in the presence of silicate. Specifically, silicate can react with MgO and Al2O3 in CLDHs to generate magnesium silicate hydrate and geopolymer-like substance which were covered on the surface of particles, blocking the hydroxylation of metal oxides. However, higher pH suppressed the interaction between MgO and silicate and enhanced the formation of geopolymer-like substance, which promoted the regeneration of LDHs. Al in CLDHs plays a critical role in the regeneration of LDHs. Besides, the ternary oxides (CLDH-2, Mg2Al0.75Fe0.25-oxide; CLDH-3, Mg2Al0.5Fe0.5-oxide) possessed larger specific surface areas (127.7 and 158.2 m2/g) and consequently presented more resistance to the effect of silicate.

本文言語英語
論文番号122674
ジャーナルJournal of Hazardous Materials
395
DOI
出版ステータス出版済み - 8 5 2020

All Science Journal Classification (ASJC) codes

  • Environmental Engineering
  • Environmental Chemistry
  • Waste Management and Disposal
  • Pollution
  • Health, Toxicology and Mutagenesis

フィンガープリント 「Influence of silicate on the structural memory effect of layered double hydroxides for the immobilization of selenium」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル