The four UV-mediated systems: UVC, UVC/H2O2, VUV and
VUV/H2O2, were able to provide a high degree of decolourisation of
the secondary effluent. The systems which support the production
of hydroxyl radicals were shown to be more effective for improving
the quality of the secondary effluent compared with direct UVC
photolysis.
When the same concentration of hydrogen peroxide was added
to either the UV or VUV system, similar overall removal of organics
was observed. Doubling the dose of hydrogen peroxide with UVC