Colferrox provides the innovative treatment of contaminated groundwater, wastewater, and soil with colloidal (iron oxide) nanoparticles. Large amounts of contaminants (heavy metals, Cyanide, etc.) are adsorbed onto the surface of colloidal iron oxide particles. The particles can be injected into the subsurface and used in separation tanks and other water treatment facilities. This solution is cost-effective, easily implemented, and environmentally friendly.