A photoreactor assembly comprising a reactor, wherein the reactor is configured for hosting a fluid to be treated with light source radiation selected from one or more of UV radiation, visible radiation, and IR radiation, wherein the reactor comprises a reactor wall which is transmissive for the light source radiation, wherein:
- the reactor is a tubular reactor, and wherein the reactor wall defines the tubular reactor;
- the tubular reactor is configured in a coiled tubular arrangement;
- the photoreactor assembly further comprises a light source arrangement comprising a plurality of light sources configured to generate the light source radiation, wherein the reactor wall is configured in a radiation receiving relationship with the plurality of light sources;
- and
- wherein the coiled tubular arrangement and the light source arrangement both define polygons having mutually parallel configured polygon sides;
- wherein the plurality of light sources comprise Chips-on-Board light sources (COB) and/or an array of Light emitting diodes (LEDs).