In-situ technologies for groundwater treatment: the case of arsenic - In-Situ Remediation of Arsenic-Contaminated Sites - page 13

Figure 1.4. Schematic representation of changes resulting from using reactive barriers with added metallic
iron with particle size in the range of 3-6 mm (upper part) vs . the use of nanoparticles or iron colloids (Kaplan
et al ., 1996).

1.6 USE OF IRON NANOPARTICLES

1.6.1 Increase of the reactivity by size decrease
As said before, iron has a high efficiency for elimination of a large amount of organic and inorganic
pollutants. However, reactivity is limited by the characteristics of the medium, the pollutant and
the material. A high reactivity is important for the application in reactive barriers because the
major part of the cost of this technology is in the excavation and installation of the barrier; for this
reason, the higher the volume of the barrier, the higher will be its cost. Therefore, if the reactivity