An overview of preparation and applications of stabilized zero-valent iron nanoparticles for soil and groundwater remediation

Abstract

Nano-scale zero-valent iron (nZVI) is one of the most intensively studied materials for environmental cleanup uses over the past 20 years or so. Freshly prepared nZVI is highly reactive due to its high specific surface area and strong reducing power. Over years, the classic borohydride reduction method for preparing nZVI has been modified by use of various stabilizers or surface modifiers to acquire more stable and soil deliverable nZVI for treatment of different organic and inorganic contaminants in water and soil. While most studies have been focused on testing nZVI for water treatment, the greater potential or advantage of nZVI appears to be for in situ remediation of contaminated soil and groundwater by directly delivering stabilized nZVI into the contaminated subsurface as it was proposed from the beginning. Compared to conventional remediation practices, the in situ remediation technique using stabilized nZVI offers some unique advantages. This work provides an update on the latest development of stabilized nZVI for various environmental cleanup uses, and overviews the evolution and environmental applications of stabilized nZVI. Commonly used stabilizers are compared and the stabilizing mechanisms are discussed. The effectiveness and constraints of the nZVI-based in situ remediation technology are summarized. This review also reveals some critical knowledge gaps and research needs, such as interactions between delivered nZVI and the local biogeochemical conditions.

An overview on heterogeneous Fenton and photoFenton reactions using zerovalent iron materials

“…It is important to recall that it is mandatory to acidify the effluents before the reaction and subsequently neutralize the treated solutions before disposal. Due to these problems, in the mid-1990s, researchers started to develop heterogeneous catalysts for the Fenton reaction using solid iron-containing compounds or solid materials rich in iron for the degradation of a wide range of organics at lower operational cost [18,40,[68][69][70][71][72][73][74]. Decomposition of aqueous H 2 O 2 over some metals (Ag, Cu, Fe, Mn, Ni, and Pt) and their oxides on supported silica, alumina, and zeolites has been a subject of research since the beginning of the previous century [75].…”

Environmental Nanoremediation under Changing Climate

“…This remediation has cost effective solutions in challenging the problems of the environmental cleanup from pollutants (El-Temsah et al 2016). For example, some nanoparticles can be used in remediation of soil or waste water or groundwater pollution because these nanomaterials have the following characterizations (1) the very small size of these nanoparticles can make the injection of them into very small spaces easy and remain active for a long time, (2) the large surface area can help to a high enzymatic activity, (3) the movement of these nanoparticles can be transported with the flow of water and is controlled by gravitational sedimentation, (4) and these nanoparticles can be adsorbed on the solid matrix (Araújo et al 2015;Guan et al 2015;Liu et al 2015;Louie et al 2016;Zhao et al 2016;Dasgupta et al 2017;Kaur et al 2017). …”

Polydimethylsiloxane as a Matrix for the Stabilization and Immobilization of Zero‑Valent Iron Nanoparticles. Applications to Dehalogenation of Environmentally Deleterious Molecules

“…Also, some nanotechnologies for water treatment are promising as efficient 'remediators' because of the high surface/volume ratios intrinsic to nanomaterials. 14 In that regard, zero-valent iron nanoparticles (nFe 0 ) are useful for the dehalogenation of HOCs; [15][16][17] they are highly reactive toward halogenated molecules and low in cost. 14,18 However, they react rapidly as well with oxygen in the air or dissolved in a liquid, 19 leading to iron oxides which are less efficient as dehalogenation agents.…”