| Abstrakt: |
Ozonation of citric acid in water catalyzed by different ions from the first row of transition metals (Mn 2+ , Co 2+ , Ti 4+ , Fe 2+ , Cu 2+ , Ni 2+ and Zn 2+ ) was investigated at room temperature. The results showed that at pH=2, where the decomposition of citric acid is negligible by only ozone, the following order of efficiency of metallic ions for the decomposition of citric acid by ozone, and also for the TOC removal, was obtained: Mn 2+ > Co 2+ > Ti 4+ > Fe 2+ . Cu 2+ , Ni 2+ and Zn 2+ showed negligible efficiency under the same experimental conditions. At pH=5.5, Mn 2+ and Co 2+ showed slightly higher efficiency than at pH=2 while Ti 4+ and Fe 2+ showed insignificant effect at this pH value. On the other hand, at pH=7 the investigated catalysts showed no obvious catalytic efficiency for the decomposition of citric acid by ozone. [ABSTRACT FROM AUTHOR] |
