Fluid treatment system

A fluid treatment system having: an inlet; an outlet; and a fluid treatment zone disposed therebetween. The fluid treatment zone has: (i) an elongate first radiation source assembly having a first longitudinal axis, and (ii) an elongate second radiation source assembly having a second longitudinal axis. The first and second longitudinal axes are non-parallel to each other and to a direction of fluid flow through the treatment zone. The present fluid treatment system can treat large volumes of fluid (e.g., wastewater, drinking water or the like); it requires a relatively small "footprint"; it results in a relatively lower coefficient of drag resulting in an improved hydraulic pressure loss/gradient over the length of the treatment system; and it results in relatively lower (or no) forced oscillation of the radiation sources thereby mitigating breakage of the radiation source and/or protective sleeve (if present).