A short review on the preparation and use of iron nanomaterials for the treatment of pollutants in water and soil

Abstract

Iron-based nanomaterials are increasingly used in environmental applications. Different types of iron-based nanomaterials, namely, zerovalent iron nanoparticles, nanoparticles of iron oxides, and nanoparticles prepared from iron salts and natural extracts by green procedures, are briefly indicated in this short review, together with their preparation, characterization, and applications in the treatment of pollutants in water and soils, with emphasis on the works performed in the last 10 years. The present short review will focus on the preparation and recent advancements (last 10 years) in the application of iron-based nanoparticles on the removal of pollutants in water (mainly) and soils. In terms of preparation, top-down procedures such as mechanical milling, nanolithography, laser ablation, sputtering, and thermal decomposition and bottom-up methods such as chemical synthesis, sol–gel, spinning, chemical vapor deposition (CVD), pyrolysis, and biosynthesis are indicated for nanoparticle production. The most commonly used nanomaterials are inorganic nanoparticles based on metal and metal oxides and, among them, iron-based materials have been widely used on the removal of pollutants in water. Among pollutants, halogenated organics; nitroaromatics; pesticides; dyes; antibiotics; halogenated aromatics; phenolic compounds; PCBs; inorganic anions such as nitrate and heavy metals and metalloids (e.g., Hg, Pb, Cr, Cu, As, Ni, Zn, Cd, and Ag); radioisotopes of Ba, TcO4, and U; and antibacterial activity against Gram-positive and negative bacteria have been successfully treated. In some cases, iron-based nanoparticles have been combined with H2O2 in Fenton processes. The advantages of using these materials and the need for their improvement to extend their deployment are remarked.