Iron Oxide Nanoparticles and Reclamation of Mine Sites

Abstract

Iron oxide nanoparticles (IOPs) are composed of iron and oxygen. In situ and ex situ methods are followed in the synthesis of IOPs. Green synthesis of IOPs using phytochemicals offers sustainable and environmentally friendly approaches for the synthesis of IOPs. Iron oxides have low solubility in water and high energy of crystallization. So IOPs exist as minute crystals having high specific surface areas. Consequently, IOPs pose high-efficiency adsorption. Adsorption process has the advantage that the process does not generate toxic by-products. Magnetic IOPs are easy to separate from the aqueous media. Adsorption and kinetic models are used to explain adsorption rate and maximum adsorption capacity of the IOPs. Fabricated IOPs having coated shell with carbon, polymer, etc., are developed for the reclamation of mine sites. These conjugates showed high-efficiency adsorption under varying environmental conditions such as pH and temperature. Colloidal systems of zero valent Fe (Fe0) act as a strong reducing agent, which converts mobile toxic trace elements to immobile. Modifications of agricultural and industrial waste residues with IOPs help to generate low-cost field remediation agents. Thus IOPs based techniques allow development of sustainable mine drainage systems filters and eco-friendly mine site remediation.