An ultraviolet (UV) fluid-treatment apparatus comprises a plurality of elongate, cylindrical UV lamps 4 mounted with their longitudinal axes generally horizontal, such that when fluid 3, 7 flows onto a first lamp the fluid is caused to form a film on the lamp surface, and to flow from the first lamp to a second lamp and form a film on a surface of the second lamp. The lamps may be arranged in a ladder-, lattice-, herringbone- or pyramid-like array (see figures 3-6). A divider (9, fig. 3) may divide and guide fluid flowing from the first lamp to the second lamp and from the first lamp to a third lamp. A fourth lamp may be provided at the same vertical level as the first lamp, with fluid flowing from the fourth lamp to a fifth lamp (see figures 5 & 6). The fluid may flow under gravity. The apparatus may include a housing 20 to which the lamps are attached. The apparatus is intended to promote a thin film of fluid flow across the surface of the lamps in order to assist treatment of fluids having low UV transmissivity such as milk or juices.
