Applications of nanoscale zero-valent iron and its composites to the removal of antibiotics: a review

Nanoscale zero-valent iron (nZVI, nFe(0)) particles have been investigated in recent years as a promising material for the removal of antibiotics from water environment. Although the potential benefits of nZVI in environmental remediation are considerable, there is a distinct need to rationally apply zero-valent iron-based (nano)materials to antibiotics removal in hydrosphere. This review supplied current opinions about the most recent works, which have been carried out toward the applications of various zero-valent iron-based (nano)materials (e.g., pristine nZVI, surface-modified nZVI, porous material-supported nZVI, inorganic clay mineral-supported nZVI and material-encapsulated nZVI) to the removal of antibiotics from water. The corresponding interaction mechanisms between the various zero-valent iron-based (nano)materials and the antibiotics, including adsorption, reduction, oxidation and other special interaction mechanisms, were discussed. The key influencing factors affecting the reactivities of the zero-valent iron-based (nano)materials with antibiotics (e.g., solution pH, solution temperature, nZVI dosage, coexisting oxy-anions and cations) were highlighted. It demonstrated that the zero-valent iron-based (nano)materials possess high reactivities with antibiotics and have great application prospects in water environmental remediation.