The invention relates to a process for treating effluents (2) moving between the inlet (4) and outlet (5) of a reactor (1), the process consisting in treating the effluents by means of a cold plasma treatment and by means of a UV-photocatalytic agent in order to produce oxidizing species for treating the effluents. In accordance with the invention, the process consists in treating the effluents with a cold plasma treatment simultaneously with the action of a UV-photocatalytic agent, the cold plasma treatment being carried out in a manner that is integrated into and located within a bed of porous microbeads (9) placed inside the reactor (1) and carrying the photocatalytic agent in order to generate oxidizing species as well as to diffuse them within the bed.