Nanoremediation: Tiny Objects Solving Huge Environmental Problems

Abstract

Background: The application of zero-valent iron nanoparticles (nZVI) to remediate soil and groundwater has gained increased attention within the last decade, primarily due to their high reactivity, cost-effectiveness and potential to treat a broad range of contaminants (e.g., chlorinated organic solvents, inorganic anions, or metals). Objective: In this paper, the state of the art of applicability of nanomaterials, especially the most frequently used nZVI in soil and groundwater, is presented. The purpose of this article is to give an overview of the current knowledge pertaining to the synthesis, employment, limitations, and risk of iron nanoparticles. Methods: Therefore, the authors have reviewed and discussed the recent patents and papers related to the developments and approaches made on the synthesis of iron nanoparticles, emphasizing the justification of green synthesis methods. The studies related to the effective use of nanoparticles in remediating organic and inorganic contaminants are addressed. The potential limitations, challenges, and risks of this innovative nanoremediation technology are also discussed. Results: Studies suggest that nZVI have successfully been applied in nanoremediation, however little is known about the particles’ fate and impacts. Additionally, it has already been proven that synthesis and modification can largely determine the physicochemical and biological properties of the particles. Conclusion: This review corroborates the suitability of nanoparticles in the remediation of contaminated media, simultaneously highlighting the work still needed to optimize the syntheses and careful use of such materials, concluding that comprehensive screenings should be performed prior nZVI applications to assess their behavior and impact on the environment and living systems.