Progress in developing the fixed bed, catalytic ozonation process “ECOCLEAR” continues. Experimental evidence supports a reaction mechanism that predominantly takes place at the surface of the solid catalyst. This sets “ECOCLEAR” apart from all other advanced oxidation techniques which depend on the presence of ·OH radicals in the aqueous phase. The catalytic ozonation process requires less ozone, is substantially less affected by dissolved radical scavengers such as (bi)carbonates and is equally effective under both highly acidic conditions – when ·OH radicals are not formed – as well as under highly alkaline conditions. Results of industrial plants in operation are given.