Magnetic nanoparticles: Essential factors for sustainable environmental applications

• Published in: Water research (Oxford) 2013-05, Vol.47 (8), p.2613-2632
• Main Authors: Tang, Samuel C.N., Lo, Irene M.C.
• Format: Article
• Language: English
• Subjects: Amino Sugars; Applied sciences; desorption; Environmental Restoration and Remediation - economics; Environmental Restoration and Remediation - methods; Exact sciences and technology; iron; Iron Compounds - chemistry; Iron Compounds - toxicity; Maghemite; Magnetic; Magnetics; Magnetite; Metal Nanoparticles - chemistry; Metal Nanoparticles - toxicity; Nanoparticles; Pollution; Remediation; Water Purification - economics; Water Purification - methods; Water treatment and pollution; Zero-valent iron
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2013.02.039

In recent years, there has been an increasing use of engineered magnetic nanoparticles for remediation and water treatments, leading to elevated public concerns. To this end, it is necessary to enhance the understanding of how these magnetic nanoparticles react with contaminants and interact with the surrounding environment during applications. This review aims to provide a holistic overview of current knowledge of magnetic nanoparticles in environmental applications, emphasizing studies of zero-valent iron (nZVI), magnetite (Fe3O4) and maghemite (γ-Fe2O3) nanoparticles. Contaminant removal mechanisms by magnetic nanoparticles are presented, along with factors affecting the ability of contaminant desorption. Factors influencing the recovery of magnetic nanoparticles are outlined, describing the challenges of magnetic particle collection. The aggregation of magnetic nanoparticles is described, and methods for enhancing stability are summarized. Moreover, the toxicological effects owing to magnetic nanoparticles are discussed. It is possible that magnetic nanoparticles can be applied sustainably after detailed consideration of these discussed factors. [Display omitted] ► This article reviews the contaminants removal mechanisms of magnetic nanoparticles. ► Desorption of contaminants mainly depends on removal mechanisms. ► Magnetic nanoparticles recovery with magnetic field requires further study. ► Stability and reactivity have to be balanced during surface modification. ► Type of bacteria and determination method greatly affect the toxicity results.