Abstract:
Remediation of contaminated soils is an important task which aims to reduce the impact of toxic
metalloids such as Cd, Cu and As on public health. In-situ immobilization via the addition of soil
amendments such as iron-based materials reduces the mobility and transport of these toxic
metalloids in the environment. A wide range of iron-based materials have been used for metal
immobilization in contaminated soils including iron oxides, zerovalent iron, nano-zerovalent iron
(nZVI), iron salts, green synthesized iron oxide nanoparticle (GION) or phytogenic iron oxides
nanoparticles (PION), Fe-Al layered double hydroxide and CMC (carboxymethylcellulose)
based iron. The reactivity and surface area of zerovalent iron is increased at the nanoscale when
utilized as nZVI thereby increasing its effectiveness as demonstrated by previous studies. The
efficiency of nZVI in remediation of contaminated soils is limited by the strong tendency of its
particles to agglomerate. In order to overcome this limitation and facilitate the delivery and
mobility of nZVI in soils, nZVI is immobilized onto a carrier such as resin, potato starch, zeolite,
or mesoporous silica or by increasing colloidal stability with the addition of other soil
amendments. Even though, there is g rowing concern over the environmental impact of
nanoparticles, the use of plant extracts to synthesize iron nanoparticles is environmentally
friendly and economical. |
