The synthesis of zero­valent nano­dimension iron on the surface of montmorillonite and organomontmollonite by reducing aqueous solutions of Fe 2+ salts by sodium boronhydride was conducted. The results of RFA and IR­spectroscopy indicate formation of a monolayer of SAS (HDTMA) both on the outer surface of the particles of montmorillonite and among structural packages of montmorillonite. In this case, organofilization of the surface contributes to the formation of more dispersed particles of zero­valent iron. The physical and chemical features of the processes of sorption cleaning of contaminated waters from chromium(VI) compounds using the obtained nanodispersed material were explored. It was established that the sorption of ions Cr(VI) by the composite adsorbent based on zero­valent iron and organomontmorillonite amounts to 120 mg/g of Fe, which significantly exceeds sorption for the original montmorillonite, organomontmorillonite, nano­dimension iron and the composite sorbent based on montmorilonite and nano­dimension iron. Based on the study of structural and rheological properties, it was established that with the content of iron in sorbent equal to 0,037÷0,146 %, the suspension remains resistant to aggregation and sedimentation. This, together with their rather high sorption characteristics, makes it appropriate to use aqueous dispersions of organomontmorillonite with the applied layer of the synthesized highly dispersed reactive material when cleaning ground waters from ions of heavy metals (chromium) using the latest environmental technologies based on pumping aqueous dispersions of nanomaterial into contaminated layers of soil.