Photodegradative process for the purification of contaminated water

A photodegradative process is described for the purificabastion of water contaminated by ether-based compounds, especially methylterbutyl ether (MTBE) or its analogous products, which comprises the following steps: (a) treatment of the contaminated water with an inorganic acid up to a pH ranging from 4.0 to 4.5 with the elimination of the carbon dioxide thus formed; (b) dispersion in the water of solid particles of a metal oxide of the semiconductor type or dissolution of a stream consisting of ozone in pure oxygen or air; (c) irradiation of the dispersion or solution obtained in step (b) with ultraviolet light to degrade the ether-based contaminants.