reported on the oxidation
of 2-chloroethanol by H2O2 under UV
irradiation, their results showed that the oxidation of
2-chloroethanol generated significant amounts of Cl−
ions and their yields increased with substrate degradation.
Similar dechlorination reactions occurred during
the ozone initiated oxidation of 2-chloroethanol.
Table 3 shows data for measured conductivity of the
reaction mixture after 3, 6, 9, and 12 h, respectively. It
is evident from the results of these measurements that
there is a steady increase in conductivity of the reaction
mixture as the ozonation time is increased. This is
most likely due to the presence of the chloride ion
formed during the ozonation process, since it is the
only conducting species that can contribute significantly
to the specific conductivity of the reaction
mixture. We would expect the conductivity of the
partially dissociated weak organic acids to be negligible.
With higher ozone contact time with the reaction
mixture, it is evident that the chloride ion content
increases sharply, which suggests that ozone mass
transfer and hence cleaving of the C–Cl bond is improved
at higher ozonation times. A marginal improvement
in the rate of chloride ion formation is
observed when ozone reactions were conducted in the presence of activated charcoal indicating that the
breaking of the C–Cl bond in 2-chloroethanol is enhanced
in the presence of activated charcoal. The
pattern of chloride formation in reactions with solvent
is similar to that in reactions with substrate alone. A
significant increase of both parts per million chloride
ion and solution conductivity in the presence of 20 %
solvent is observed. Therefore, solvent with a higher
strength is said to significantly improve the ozonation
process resulting in an increase in C–Cl bond cleavage
to thus give the highest concentration of chloride ions
in the reaction mixture