This paper presents a new hybrid process for the treatment of industrial waste water. It combines pervaporation as a means of separating the pollutant from the condensed aqueous phase by phase transfer and vacuum-UV (VUV) gas phase photolysis for the oxidative degradation of the organic pollutant. Organic substances dissolved in water are separated and concentrated in a multistage pervaporation process. The gaseous permeate is subsequently oxidised and mineralised in a VUV-photochemically induced oxidation process. In contrast to the VUV-photolysis of aqueous solutions, gas phase photolysis is highly energy efficient. The process combination was developed from bench to pilot scale. The results show that industrial waste water containing organic pollutants can be purified to very low residual concentration permitting recycling, re-use (irrigation) or release into the environment. (C) 2002 Elsevier Science B.V. All rights reserved.