A fluid treatment apparatus for sterilizing drinks comprises an elongated tubular duct (110) and an elongated UV light source (111) extending longitudinally along the duct (110). The fluid flows longitudinally along the duct (110) in a thin annular low passage (114) which extends around the UV light source (111). A mixing device (112), disposed between adjacent longitudinal portions of the duct (110), diverts the fluid from a first portion of the passage (114) through fluid mixing means (113, 116) in the device (112) and returns the mixed fluid to a second portion of the passage (114). Micro-organisms in the fluid flow are killed as they come close to the light source (111). The mixing device (112) mixes the flow and returns it to the flow passage (114). A plurality of mixing devices along the duct (110) increases the likelihood that microorganisms receive a sufficient lethal dose of UV radiation.
