As(V) adsorption onto nanoporous titania adsorbents (NTAs): Effects of solution composition

Dong Suk Han, Bill Batchelor, Sung Hyuk Park, Ahmed Abdel-Wahab

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8 Citations (Scopus)

Abstract

This study has focused on developing two nanoporous titania adsorbents (NTA) to enhance removal efficiency of adsorption process for As(V) by characterizing the effects of pH and phosphate concentration on their sorption capacities and behaviors. One type of adsorbent is a mesoporous titania (MT) solid phase and the other is group of a highly ordered mesoporous silica solids (SBA-15) that can incorporate different levels of reactive titania sorption sites. Microscopic analysis showed that Ti(25)-SBA-15 (Ti/SBA=0.25g/g) had titania nanostructured mesopores that do not rupture the highly ordered hexagonal silica framework. However, MT has disordered, wormhole-like mesopores that are caused by interparticle porosity. Adsorption experiments showed that Ti(25)-SBA-15 had a greater sorption capacity for As(V) than did Ti(15)-SBA-15 or Ti(35)-SBA-15 and the amount of As(V) adsorbed generally decreased as pH increased. Higher removal of As(V) was observed with Ti(25)-SBA-15 than with MT at pH 4, but MT had higher removals at higher pH (7, 9.5), even though MT has a lower specific surface area. However, in the presence of phosphate, MT showed higher removal of As(V) at low pH rather than did Ti(25)-SBA-15. As expected, the NTAs showed very fast sorption kinetics, but they followed a bi-phasic sorption pattern.

Original languageEnglish
Pages (from-to)273-281
Number of pages9
JournalJournal of Hazardous Materials
Volume229-230
DOIs
Publication statusPublished - 30 Aug 2012

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Keywords

  • Adsorption
  • Arsenate
  • Nanoporous adsorbent
  • Phosphate
  • SBA-15
  • Titania

ASJC Scopus subject areas

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

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