Currently, the textile industry is one of the most important economic sectors in many countries. Besides, it is known as a major consumer of water and consequently one of the largest groups of industries causing intense water pollution. Chemicals, including surfactants, dyes, resins, dispersants agents, inorganic salts, etc., play a variety of functions during the textile processing and are present as a by-product in large volumes of toxic wastewater. As a consequence, textile industry has been challenged for colour removal, salt content reduction and elimination of the non-biodegradable organic fraction from the generated wastewaters. Biological processes are the preferred choice for textile wastewater treatment because they are less costly, and the by-products resulting from complete degradation are not toxic. However, conventional biological processes do not always provide satisfactory results, since many of the organic substances used in the textile industry are toxic or recalcitrant. Advanced oxidation processes (AOPs) have been considered a promising wastewater treatment technology for the elimination of recalcitrant/toxic organic pollutants, as those present in textile wastewaters. The main aim of this thesis was the study of alternative processes for the treatment of textile wastewaters, combining AOPs and biological oxidation. The treatment strategy was applied to four different textile wastewater, two real textile wastewaters and two synthetic ones.