Photo reactor: A photo reactor which includes at least one baffle comprising a light source

An apparatus comprising a vessel to receive and discharge fluids, the vessel comprising a series of tubular members, each defining a discrete process zone, the tubular members being connected in a flow system to form at least one continuous fluid flow path having an inlet and an outlet, wherein at least one baffle is provided within a tubular member and at least one light source is provided on the baffle(s) which emits light into the fluid flow path during use. A baffle may comprise a plurality of light sources e.g. an LED or LED array, which can be arranged on both sides of the baffle and/or regularly or irregularly around the baffle surface. The apparatus can comprise a plurality of reaction zones, each zone having at least one baffle comprising a plurality of light sources. The wavelength and/or intensity emitted by the light sources in one zone can be the same or different as that in another zone. The baffle is preferably an orifice baffle which can be mounted on rails attached to the inner surface of the tubular members e.g. tubes. A baffle assembly which also includes a power source and a controller is also described.