In addition, the lower ozone consumption observed at
the end of this treatment (71 mgO3/L after 10 min) can be the
consequence of scavenger effect of the combination of H2O2
and TiO2 with O3. As it can be observed in Table 3, those treatments with a higher consumption of ozone achieve higher levels of inactivation of E. coli. The consumption of ozone is related with its decomposition. Theoretically, the decomposition
of ozone that favors the inactivation of microorganisms
due to a higher amount of hydroxyl radicals can be generated. All these results are in agreement with those shown by other authors. For instance, Lanao et al. (2008) showed that the population of Clostridium perfringens behaved similarly to that of E. coli using the same experimental conditions, achieving the highest level of inactivation with the peroxone system. Cho and Yoon also obtained higher levels of inactivation
of the spores of Bacillus subtilis with the peroxone
system than with ozonation, suggesting that the hydroxyl radicals produced in the peroxone system are more effective than the ozone molecule (Cho and Yoon 2006).