Background The textile sector has high levels of water consumption and generates significant pollution. Much progress has been made in water treatment. However, the organic compounds in wastewater generated by dyeing are barely treated by conventional wastewater systems. Existing research on photo oxidation treatment suggests that application to textile outflows may be a suitable option for the elimination of organic compounds. Objectives This project examined and demonstrated the effectiveness of applying photo-oxidation treatment to industrial wastewater. Such wastewater comes either from a secondary active sludge biological treatment or before. A semi-industrial scale prototype using the new purification treatment was introduced into the depurating system of the partner company. The aim of the research was to determine the technical and economic feasibility of the new treatment when working in a continuous industrial flow process. The project also aimed to achieve high quality outgoing water for reuse in the same industry. The project thus tackled two environmental problems: pollution of water and high water consumption. The specific objectives are: •Ancillary treatment feasibility study on a semi-industrial scale. •Pilot plant set up (prototype: photochemical reactor for continuous operation) •Establish the feasibility of using purified wastewater. •Verify the advantage of reusing treated water •Disseminate and transfer technology to other SMEs. •Establish the technical and economic feasibility as well as environmental benefits. Results The most important result is that the application of photo-oxidation techniques for the removal of biodegradable and non-biodegradable organic compounds in textile wastewaters require simple lighting installations and accessible re-agents. This allows for waste problems caused by many textile processes to be solved in a financially viable manner. The advantage of such techniques is that organic substrate degradation is derived from its generality comprised of a high number of organic compounds with a great variety of functional groups. The project indicated that such a technique can be effective in the treatment of several kinds of effluents. The photo-oxidation treatment achieved high reductions in organic polluting load and removes the coloration from the wastewaters. However, photo-oxidation does not decrease but increases conductivity considerably due to the mineralization of the organic matter. Reusing purified water requires treatment to decrease the level of dissolute salts. Following treatment, and according to the quality parameters that the water must have in order to be reused in the production process of a textile enterprise, a combination of membrane systems, such as micro-filtration and nano-filtration, would be necessary.