Abstract: A device for the treatment of a liquid or gaseous medium, in particular water or air, using UV radiation, comprises a UV radiation source (24), with an axial longitudinal direction and an essentially perpendicular, in particular radial direction of irradiation (R), with several layers of transmissive treatment chambers (K1-K4), serially arranged one on the other in the radiation direction (R), separated from the UV radiation source (24) and from each other by a transparent, UV-transmissive separating layer (T1-T4) which is UV transparent. The chambers, beginning with a first treatment chamber (K1), adjacent to the UV radiation source, form a flow channel for the medium running in the longitudinal direction of the UV radiation source (24), the flow channel emptying (26) into the subsequent treatment chamber (K2, K3, K4) that is at a greater distance from the UV radiation source (24) in the direction of irradiation (R).

Abstract: A device for the treatment of a liquid or gaseous medium, in particular water or air, using UV radiation, comprises a UV radiation source (24), with an axial longitudinal direction and an essentially perpendicular, in particular radial direction of irradiation (R), with several layers of transmissive treatment chambers (K1-K4), serially arranged one on the other in the radiation direction (R), separated from the UV radiation source (24) and from each other by a transparent, UV-transmissive separating layer (T1-T4) which is UV transparent. The chambers, beginning with a first treatment chamber (K1), adjacent to the UV radiation source, form a flow channel for the medium running in the longitudinal direction of the UV radiation source (24), the flow channel emptying (26) into the subsequent treatment chamber (K2, K3, K4) that is at a greater distance from the UV radiation source (24) in the direction of irradiation (R).