Using H-titanate nanofiber catalysts for water disinfection: understanding and modelling of the inactivation kinetics and mechanisms

Meng Nan Chong, Bo Jin, Christopher P. Saint

Research output: Contribution to journalArticleResearchpeer-review

12 Citations (Scopus)

Abstract

The H-titanate nanofiber catalyst (TNC), which has a favourable morphological structure for mass transfer and energy access, was proven as a promising alternate titanium dioxide (TiO2) carrier for photo-inactivation of a sewage isolated E. coli strain (ATCC 11775). This study revealed that the TNC loading is a key process parameter that radically influenced the photo-inactivation of bacteria in an annular slurry photoreactor (ASP) system. Variation in the TNC loadings was found to have a considerable impact on the dissolved oxygen (DO) concentration profiles and subsequently, on the photo-inactivation rates of bacteria in the ASP system. The photo-inactivation reaction in the ASP system was found to exhibit three different bacterial inactivation regimes of shoulder, log-linear and tailing. Resultant photo-inactivation kinetics data was evaluated using both empirical and mechanistic bacterial inactivation models. The modified Hom model was found to be the best empirical model that can represent the sigmoid-type bacterial inactivation pattern. An interesting correlation between the TNC loadings and DO concentration profiles was also established. From the correlation, it was found necessary to integrate a DO limiting reactant term in the newly proposed mechanistic Langmuir-Hinshelwood model to describe the bacterial inactivation mechanisms under two different TNC loading conditions of sub-optimal and optimal, respectively.

Original languageEnglish
Pages (from-to)6525-6535
Number of pages11
JournalChemical Engineering Science
Volume66
Issue number24
DOIs
Publication statusPublished - 15 Dec 2011
Externally publishedYes

Keywords

  • Catalysis
  • Kinetics
  • Mathematical modelling
  • Nanostructure
  • Photocatalysis
  • Titanium dioxide

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