Industrial wastewater is becoming more and more complex with the increasing diversity in its composition and toxicity. In addition to the dye production plants, the textile industry produces large amounts of effluents which are toxic and resistant to destruction by physicochemical methods and/or biodegradation. Some of the medium size factories began to use biological treatment processes for their wastewater. The big size textile factories situated in industrial centers discharge their process water to central wastewater treatment plants which use classical biological treatment by mixing with domestic sewage.

The specific objective of this project is to investigate a new chemical oxidation method for dyes. It will be an energy saving photocatalytic degradation method by using sunlight. The biodegradability of the previously photocatalytically treated water will be examined. In the project, a thorough examination of the biodegradability of well-selected and relevant application products shall be carried out in the strict sense of ex­amining the mineralization processes (transformation of a compound to end products like CO₂, H₂O or CH₄) under aerobic, anoxic and anaerobic conditions.