An EPR study on wastewater disinfection by peracetic acid, hydrogen peroxide and UV irradiation

EPR spectroscopy was applied to obtain qualitative and quantitative
information on the radicals produced in disinfection processes of
wastewater for agricultural reuse. The DEPMPO spin trap was employed to
detect hydroxyl and carbon-centered short living radicals in two different
peracetic acid solutions and a hydrogen peroxide solution used for water
disinfection either in the absence or in the presence of UV-C irradiation.
Moreover, three different kinds of water (wastewater, demineralised water,
distilled water) were analysed in order to assess the contribution of
Fenton reactions to the radical production. The spectroscopic results were
discussed in relation to the efficiency of the different oxidizing agents
and UV irradiation in wastewater disinfection evaluated as Escherichia
Coli, Faecal and Total Coliforms inactivation.