The decontamination of pathogens (bacteria and yeast fungi) from non-transparent fluids (liquids or gases) using periodical structures like small quartz or glass spheres irradiated by ultraviolet (UV)-C light is proposed. Studies were devoted to the topological effect of individual metamaterial elements which modify UV-C evanescent waves in a contact zone of contaminated fluids and metamaterials, as a function of granule geometry. The efficiency of utilization of metamaterials in decontamination of non-transparent liquids is demonstrated. The decontamination efficiency is assessed both in the dynamic and static regime. Control experiments were performed in the absence of metamaterials and/or UV-C irradiation. © Springer Science+Business Media B.V.