Stabilization of Soil Arsenic with Iron and Nano-Iron Materials: A Review.

Soil arsenic (As) contamination is an important environmental problem, and chemical stabilization is one of the major techniques used to remediate soil As contamination. Iron and iron nanoparticle materials are widely used for soil As stabilization because they have one or more of the following advantages: high adsorption capacity, high reduction capacity, cost effectiveness and environmental friendliness. Therefore, this review introduces the stabilization of soil As with iron and iron nanoparticles, including zero-valent iron, iron oxides/hydroxides, some iron salts and Fe-based binary oxides and the nanoparticles of these iron materials. The mechanism of chemical soil As stabilization, which involves adsorption and the coprecipitation process, is discussed. The factors affecting the chemical stabilization process are presented, and challenges to overcome in the future are also discussed in this review.