Synthesis and Application of Zero-Valent Iron Nanoparticles in Water Treatment, Environmental Remediation, Catalysis, and Their Biological Effects

Abstract

Present and past anthropogenic pollution of the hydrosphere and lithosphere is a growing concern around the world for sustainable development and human health. Current industrial activity, abandoned contaminated plants and mining sites, and even everyday life is a pollution source for our environment. There is therefore a crucial need to clean industrial and municipal effluents and remediate contaminated soil and groundwater. Nanosized zero-valent iron (nZVI) is an emerging material in these fields due to its high reactivity and expected low impact on the environment due to iron’s high abundance in the earth crust. Currently, there is an intensive research to test the effectiveness of nZVI in contaminant removal processes from water and soil and to modify properties of this material in order to fulfill specific application requirements. The number of laboratory tests, field applications, and investigations for the environmental impact are strongly increasing. The aim of the present review is to provide an overview of the current knowledge about the catalytic activity, reactivity and efficiency of nZVI in removing toxic organic and inorganic materials from water, wastewater, and soil and groundwater, as well as its toxic effect for microorganisms and plants.

Enhanced adsorptive removal of diclofenac sodium from aqueous solution by bentonite-supported nanoscale zero-valent iron

“…Composites of nZVI have been extensively synthesized to stabilize the nZVI particles in the adsorption of residual pollutants from aqueous solutions. In addition to the increased number of active inherent surface sites, the specific surface area, and reducing the reaction time (Bhatti, Safa, et al, 2020;Li et al, 2006;Mahmood et al, 2013;Pasinszki & Krebsz, 2020;Sana, Haq Nawaz, Khalid, Jan, & Munawar, 2020;Tam et al, 2020;Theron et al, 2008;Toli, Varouxaki, Mystrioti, Xenidis, & Papassiopi, 2018).…”

Effects of in situ Remediation With Nanoscale Zero Valence Iron on the Physicochemical Conditions and Bacterial Communities of Groundwater Contaminated With Arsenic

“…Nanoscale zero-valent iron (nZVI) is the most widely used nanomaterial for soil and groundwater remediation in Europe and the United States ( Mueller et al, 2012 ; Bardos et al, 2015 ). This material is effective on a wide range of contaminants, including halogenated compounds, nitrate, phosphate, polycyclic aromatic hydrocarbons and metal(loid)s ( Jiang et al, 2018 ; Pasinszki and Krebsz, 2020 ). Among other characteristics (such as low cost, ease of production and a presumably low impact on the environment, since iron is abundant in the earth’s crust; Jiang et al, 2018 ), nZVI show high reactivity toward a broad range of pollutants and can be used in the remediation of specific targets (such as aqueous slurries).…”

“…Among other characteristics (such as low cost, ease of production and a presumably low impact on the environment, since iron is abundant in the earth’s crust; Jiang et al, 2018 ), nZVI show high reactivity toward a broad range of pollutants and can be used in the remediation of specific targets (such as aqueous slurries). These properties are attributed to the small size of the nanoparticles, which confers them a high specific surface area and mobility, and to their strong reducing capacity ( Cagigal et al, 2018 ; Pasinszki and Krebsz, 2020 ). nZVI has some drawbacks, mainly related to its tendency to aggregate, which hinders its supply and mobility in the soil ( Stefaniuk et al, 2016 ).…”

“…Soil microorganisms (the soil microbiome) form a highly complex community that performs critical activities, including soil-atmosphere gas exchange, processes related to plant growth promotion, responses to adverse environmental conditions, synthesis of bioactive compounds such as antimicrobials, immunity to pathogenic species, and driving biogeochemical cycles through the decomposition and biotransformation of organic matter and pollutants ( Zhu et al, 2019 ; Tian et al, 2020 ). Microbial biogeochemical activities also include redox transformation of arsenic via As(V) reduction and As(III) oxidation, which directly affect the mobility and bioavailability of this metalloid ( Yamamura and Amachi, 2014 ), and removal of As(V) by nZVI includes adsorption and co-precipitation reactions with Fe(II), or adsorption and oxidation of As(III) to As(V) ( Pasinszki and Krebsz, 2020 ). Finally, microorganisms and nZVI can interact, potentially participating in the oxidation-linked “aging” of nZVI ( Xie et al, 2017 ).…”

In Vitro Study of the Toxicity Mechanisms of Nanoscale Zero-Valent Iron (nZVI) and Released Iron Ions Using Earthworm Cells

“…Nanoscale zero-valent iron (nZVI) and derived nanomaterials are widely applied for nanoremediation and have shown the potential to degrade inorganic and organic pollutants in many laboratory experiments and pilot field applications [1,2]. For remediation, nZVI-based materials in the form of highly concentrated suspensions (up to 10-30 g/L) are usually injected into contaminated soil or groundwater [1].…”