Nanoscale Zero-Valent Iron Applications in Environmental Contaminant Remediation

Nanoscale zero-valent iron (nZVI) has emerged as a versatile remediation agent for a broad range of environmental contaminants, including chlorinated solvents, heavy metals and persistent organic pollutants. Its high surface-area-to-volume ratio and intrinsic reducing power derive from an Fe(0) core enveloped by an oxide layer, enabling rapid electron transfer and chemical transformation of target compounds. In aqueous and subsurface environments, nZVI promotes reductive dechlorination of halogenated hydrocarbons, precipitates and immobilises metal ions, and catalyses advanced oxidation processes when combined with activators such as persulfate. To overcome challenges of particle aggregation, limited transport and premature oxidation, researchers have developed surface modifications—sulfidation, polymer coatings or support on porous matrices—that enhance stability, selectivity and longevity. Field trials and pilot-scale studies demonstrate the potential for in situ injection and permeable reactive barriers, while ex situ treatments leverage nZVI composites in fixed-bed reactors. Ongoing work addresses optimisation of synthesis routes, controlled delivery, long-term reactivity and ecotoxicological assessments. The global significance of nZVI remediation spans contaminated industrial sites, agricultural runoff and groundwater plumes, offering cost-effective, minimally invasive solutions that reduce remediation time and mitigate secondary waste generation.

Research from Nature Portfolio

Recent studies have introduced a nanoparticle seeding approach to synthesise sulphide-modified nZVI with a well-defined core–shell architecture. By treating iron nanoparticles with controlled doses of sulphide, this method yields particles with a highly sulfidised outer layer that preserves a substantial Fe(0) core. The seeding protocol accelerates Fe2+ reduction, increases crystalline Fe(0) content and boosts magnetic susceptibility. Optimised particles exhibit over a tenfold enhancement in cadmium removal capacity and elevated electron efficiency, demonstrating promising performance for treatment of metal-contaminated water under realistic conditions.

Nanoscale Zero-Valent Iron Applications in Environmental Contaminant Remediation publication trend

The graph below shows the total number of articles in nanoscale zero-valent iron applications in environmental contaminant remediation across all publications each year (not limited to Nature Index journals).

Technical terms

Nanoscale zero-valent iron (nZVI): Elemental iron particles typically below 100 nm in diameter, featuring a reactive Fe(0) core and an oxide shell, used for reductive transformation of contaminants.

Core–shell architecture: Nanoparticles comprising an inner core of one material (e.g. Fe(0)) and an outer shell of another (e.g. iron sulfide), designed to combine distinct chemical functionalities.

Sulfidation: Surface modification of nZVI by incorporation of sulphide species, which enhances reactivity, selectivity and resistance to oxidative passivation.

Biochar: Porous carbonaceous material derived from biomass pyrolysis, employed as a support to disperse nZVI and prevent aggregation.

Electron efficiency: The fraction of electrons donated by nZVI that are utilised in target contaminant reduction reactions, serving as a measure of reactivity and selectivity.

Reductive degradation: Chemical transformation of contaminants through electron addition, typically resulting in dechlorination or conversion to less harmful species.

References

1. Incorporation of N-doped biochar into zero-valent iron for efficient reductive degradation of neonicotinoids: mechanism and performance. Biochar (2023).
2. Integrated Remediation Processes Toward Heavy Metal Removal/Recovery From Various Environments-A Review. Frontiers in Environmental Science (2019).
3. Direct Synthesis of Novel and Reactive Sulfide-modified Nano Iron through Nanoparticle Seeding for Improved Cadmium-Contaminated Water Treatment. Scientific Reports (2016).
4. Core–Shell Fe/FeS Nanoparticles with Controlled Shell Thickness for Enhanced Trichloroethylene Removal. ACS Applied Materials & Interfaces (2020).