In situ synthesis of hierarchical cobalt-aluminum layered double hydroxide on boehmite surface for efficient removal of arsenate from aqueous solutions: Effects of solution chemistry factors and sorption mechanism

Seon Yong Lee, Kyung Won Jung, Jae Woo Choi, Young Jae Lee

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6 Citations (Scopus)

Abstract

A facile route is reported for the in situ formation of three-dimensionally structured hierarchical Co-Al layered double hydroxide (CoAl-LDH) crystals on a boehmite surface (CoAl-LDH@boehmite) via the dissolution of boehmite followed by the coprecipitation of Co and Al ions on the boehmite surface. The physicochemical properties of the as-prepared materials were characterized and tested for evaluating their sorption affinity toward arsenate (As(V)) in an aqueous solution. The characterization results confirmed that the plate-like CoAl-LDH nanocrystals were densely and uniformly formed on the boehmite surface with a three-dimensional hierarchical structure. Batch experiments were conducted systematically to evaluate the effects of the sorbent dosage, initial pH, competitive anions, and temperature on the sorption behavior of CoAl-LDH@boehmite. The sorption kinetics and isotherms studies indicated that the As(V) sorption processes could be well described by the pseudo-second-order and Sips isotherm models, respectively. The sorption mechanisms were confirmed by various solid phase analyses, including X-ray diffraction, Fourier transform infrared, transmission electron microscopy, X-ray photoelectron spectroscopy, and extended X-ray absorption fine structure. These findings suggest that the intercalation of As(V) into the interlayer region via anion exchange and bidentate-binuclear inner-sphere surface complexation due to ligand exchange were responsible for the removal of As(V) by CoAl-LDH@boehmite.

Original languageEnglish
Pages (from-to)914-923
Number of pages10
JournalChemical Engineering Journal
Volume368
DOIs
Publication statusPublished - 2019 Jul 15

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Keywords

  • Anion exchange
  • Arsenic removal
  • Boehmite
  • Hierarchical structure
  • Layered double hydroxide
  • Ligand exchange

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry
  • Chemical Engineering(all)
  • Industrial and Manufacturing Engineering

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