Abstract: A purifying device adapted to perform a method of photochemical elimination of xenobiotics present in water. The purifying device comprises a photochemical reactor unit having at least one inlet for contaminated water and one outlet for purified water, it provides a flow path for continuously flowing water from said inlet to said outlet, and is equipped with a radiation source module providing ultraviolet radiation in a wavelength range ranging from 100 to 280 nm. The purifying device further comprises at least one membrane filtration unit designed to perform ultra filtration and connected upstream of said photochemical reactor unit via said inlet and at least one device for supplying air or dioxygen to the water comprised in the photochemical reactor unit. Further, a purification method is provided, using the device of the invention.