Comparison of different packing materials for the biofiltration of air toxics.

Published

Journal Article

Four different biofilter packing materials (two porous ceramics, perlite, and open pore polyurethane foam) were compared for the removal of toluene vapors. The focus was on evaluating performance at relatively short gas retention time (13.5 and 27 sec). The reactors were initially operated as biotrickling filters with continuous feeding and trickling of a nutrient solution. After significant plugging of the biotrickling filter beds with biomass was observed, the operation mode was switched to biofiltration with only periodic supply of mineral nutrients. This resulted in stable conditions, which allowed detailed investigations over > 6 months. The reactor packed with cattle bone Porcelite (CBP), a ceramic material containing some macronutrients and micronutrients, exhibited the highest performance. The critical load (i.e., load at which 95% removal occurred) was 29 g m(-3) hr(-1) at a gas retention time of 13.5 sec and 66 g m(-3) hr(-1) at a gas retention time of 27 sec. After the long-term experiment, the packing materials were taken from the reactors and examined. The reactors were divided into three sections, top, middle, and bottom, to determine whether spatial differentiation of biomass occurred. The assays included a double-staining technique to count total and live microorganisms and determination of moisture, protein, and dry weight contents. Microbial community analysis was also conducted by denaturing gradient gel electrophoresis. The results showed that most reactors had a significant fraction of inactive biomass. Comparatively, the CBP biofilter held significantly higher densities of active biomass, which may be the reason for the higher toluene removal performance. The analyses suggest that favorable material properties and the nutrients slowly released by the CBP provided better environmental conditions for the process culture.

Full Text

Duke Authors

Cited Authors

  • Sakuma, T; Hattori, T; Deshusses, MA

Published Date

  • November 2006

Published In

Volume / Issue

  • 56 / 11

Start / End Page

  • 1567 - 1575

PubMed ID

  • 17117742

Pubmed Central ID

  • 17117742

Electronic International Standard Serial Number (EISSN)

  • 2162-2906

International Standard Serial Number (ISSN)

  • 1096-2247

Digital Object Identifier (DOI)

  • 10.1080/10473289.2006.10464564

Language

  • eng