[Degradation of PCDD/Fs by the Mixture of V2O5-WO3/TiO2 Catalyst and Activated Carbon]

Huan Jing Ke Xue. 2015 Sep;36(9):3508-14.
[Article in Chinese]

Abstract

The mixture of V2O5-WO3/TiO2 catalyst and two kinds of Activated Carbons (AC) (AC-1: based on lignite; AC-2: based on coconut shell) was used to destroy gas phase PCDD/Fs with high concentration (9. 80 ng.m-3, evaluated by international toxic equivalence quantity (I-TEQ) under low thermal temperature (160°C) based on a dioxin generating system. After mixing with AC, removal efficiency (RE) and destruction efficiency (DE) of PCDD/Fs increased by 20% compared with only catalyst condition. In comparison with mixture of AC based on coconut shell, mixture of AC based on lignite had lower RE-values and higher DE-values. The adjustments of the ratio of catalyst and AC could cause the different degradation effects, and RE-values increased and DE-values decreased with increasing proportions of catalyst. When the volume fraction of oxygen was 0% in experimental atmosphere, catalyst could lose its activity and most PCDD/Fs were not oxidized but adsorbed by the mixture. RE and DE-values increased with increasing content of oxygen. The addition of ozone (concentration of 200 mg.m-3) could improve catalytic oxidation effects to a certain degree. However, ozone might react with AC, which could influence the lifetime of the mixture. Under 200°C, the mixture with proportion of AC: catalyst = 1:1 and in the present of 200 mg.m-3 ozone conditions, the highest RE and DE-value were obtained with 98. 0% and 94. 8% respectively, and the concentration of PCDD/Fs residual in off-gas was only 0. 51 ng.m-3 evaluated by I-TEQ.

MeSH terms

  • Adsorption
  • Benzofurans / chemistry*
  • Catalysis
  • Charcoal / chemistry*
  • Oxidation-Reduction
  • Oxides / chemistry*
  • Ozone
  • Polychlorinated Dibenzodioxins / analogs & derivatives*
  • Polychlorinated Dibenzodioxins / chemistry
  • Polymers / chemistry*
  • Titanium / chemistry*
  • Tungsten / chemistry*
  • Vanadium Compounds / chemistry*

Substances

  • Benzofurans
  • Oxides
  • Polychlorinated Dibenzodioxins
  • Polymers
  • Vanadium Compounds
  • polychlorodibenzofuran
  • titanium dioxide
  • Charcoal
  • Ozone
  • tungsten oxide
  • vanadium pentoxide
  • Titanium
  • Tungsten