Raw Water Treatment Plant

1. Process for the conditioning of untreated water to produce service water, in which the untreated water is fed in a mainstream successively to a flocculation, an ozone reaction stage and an after-treatment, a part-stream of the service water which has been conditioned in this way is enriched with ozone via an ozone-introduction device and is then mixed into the mainstream of the untreated water between the flocculation and ozone reaction stage, and the ozone for the ozone-introduction device is obtained from pure oxygen, characterized in that the after-treatment is an aerobic biological treatment in which exhaust gas resulting in the ozone-introduction device is fed to an oxygen enrichment preceding the flocculation, and exhaust gas produced in the oxygen enrichment is fed to the biological stage.