Ozone is very effective in decolorizing textile effluents.
The decomposition rate of ozone is affected by
pH and initial dye concentration. At basic pH, ozone
rapidly decomposes to yield the hydroxyl radical and
other radical species in solution. Under acidic conditions,
ozone can directly react with organic substrates
as an electrophile. Ozone is frequently used for decolorizing
dye wastewaters because it attacks conjugated
double bonds which are often associated with color.
Ozone decomposition is also affected by the presence
of inorganic/organic species in the reaction medium.
On the other hand, ozone molecular reactions are
selective, and in most cases, they proceed through
electrophilic attack, though ozone can react through
nucleophilic or oxygen transfer pathways.