Nanomaterials for soil remediation: Pollutant immobilization and opportunities for hybrid technologies

Abstract Nanoremediation is a promising technology for soil reclamation. This approach consists of soil amendment with nanomaterials to immobilize inorganic pollutants by means of sorption, precipitation, or oxidation/reduction mechanisms. The core-shell structure of zero-valent iron nanoparticles supports several immobilization mechanisms, as demonstrated in field-scale work, and thus making these particles the most widely used nanomaterials for remediation purposes. Other nanomaterials, including several types of iron oxides and carbon-based materials, have also yielded satisfactory results in remediation studies. Most of these studies, irrespective of the nanomaterial used, have been conducted on soils affected by metal and metalloid pollution. Although nanoremediation is focused on the immobilization of pollutants, recent work has addressed combining this technology with other classical remediation approaches, such as phytoremediation and soil washing. Given the enormous potential of nanotechnology to design novel compounds, nanoremediation opens up a new scenario in remediation technologies that requires additional testing at lab-, pilot-, and field-scales.