A fluid treatment system by force of thermophoresis, including first and second modules between which the fluid to be treated is intended to circulate, the first module configured to be brought to a temperature greater than that of the second module so as to engender a temperature gradient causing a force of thermophoresis capable of projecting the particles to be purified in the direction of the second module. The first module includes a succession of parallel first tubes configured to be traversed by hot fluid, the second module includes a succession of parallel second tubes configured to be traversed by cold fluid, and the first tubes are arranged staggered with the second tubes.