Adsorption enhancement mechanisms of silica-titania nanocomposites for elemental mercury vapor removal

Erik Pitoniak, Chang Yu Wu, David W. Mazyck, Kevin W. Powers, Wolfgang Sigmund

Research output: Contribution to journalArticlepeer-review

114 Scopus citations

Abstract

A novel nanocomposite that combines high-surface area silica with the photocatalytic properties of titania has been developed that allows for effective capture of elemental mercury vapor. The adsorption capability of the developed material has been found to improve after periods of photocatalytic oxidation. In this study, the mechanisms for adsorption enhancement were identified. BET nitrogen adsorption and mercury porosimetry were used to evaluate pore structure, and the results suggest that a decrease in contact angle was likely to be responsible for improved mercury capture overtime. Contact angle measurements showed a significant change of more than 10°, indicating greater attraction to mercury for the used pellets due to deposited mercuric oxide. ICP and TGA analyses showed that mercury was captured as both elemental mercury (Hg0) and mercuric oxide (HgO). In addition, it was shown that pellets used for nearly 500 h still showed greater than 90% removal efficiency and had an average capacity of 10 mg of Hg/g based on mass balance calculations, while some pellets had a capacity over 30 mg of Hg/g according to ICP and TGA analyses. Mercuric oxide doped pellets removed 100% of elemental mercury without pretreatment. The superior mercury removal efficiency combined with various advantages of the novel composite demonstrates its use as an effective alternative to conventional activated carbon injection technology.

Original languageEnglish (US)
Pages (from-to)1269-1274
Number of pages6
JournalEnvironmental Science and Technology
Volume39
Issue number5
DOIs
StatePublished - Mar 1 2005

All Science Journal Classification (ASJC) codes

  • General Chemistry
  • Environmental Chemistry

Fingerprint

Dive into the research topics of 'Adsorption enhancement mechanisms of silica-titania nanocomposites for elemental mercury vapor removal'. Together they form a unique fingerprint.

Cite this