Chromium Contaminant Management in Industrial Waste

Chromium, particularly in its hexavalent form (Cr(VI)), is a pervasive contaminant in effluents and solid residues generated by electroplating, leather tanning, pigment manufacture and chromite ore processing. Owing to its high solubility, mobility and recognised carcinogenicity, Cr(VI) poses acute risks to aquatic ecosystems and human health. Management strategies hinge upon reducing Cr(VI) to the less soluble and less toxic trivalent state (Cr(III)), followed by immobilisation or recovery. Conventional approaches employ chemical reductants such as ferrous salts or zero‐valent iron, often integrated with pH control to precipitate Cr(III) hydroxides. Emerging technologies harness adsorbent materials—including layered double hydroxides (LDHs), metal–organic frameworks and biogenic minerals—to sequester Cr species via surface complexation. Bioremediation exploits indigenous or engineered microbes capable of enzymatic Cr(VI) reduction, offering low‐energy treatment options for contaminated soils and groundwater. Parallel efforts address circular economy objectives by valorising chromium‐bearing waste: recovered Cr(III) can serve as a precursor for stainless steel or catalysis, while residual iron oxides find use in pigment and magnetic applications. Regulatory limits and discharge permits continue to drive innovation towards hybrid systems that combine rapid reduction kinetics with efficient separation and minimal secondary waste. Nonetheless, scale‐up and long‐term stability under variable field conditions remain key challenges for next‐generation remediation schemes.

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Chromium Contaminant Management in Industrial Waste publication trend

The graph below shows the total number of articles in chromium contaminant management in industrial waste across all publications each year (not limited to Nature Index journals).

Technical terms

Cr(VI): Hexavalent chromium, a highly soluble, mobile and toxic form of chromium.

Zero‐valent iron (ZVI): Metallic iron used as a reductant to convert Cr(VI) to Cr(III) in situ.

Layered double hydroxide (LDH): A class of anionic clays capable of interlayer anion exchange and adsorption of contaminants.

Chromite ore processing residue (COPR): Alkaline solid waste generated during the extraction of chromium from chromite ore.

Hydrothermal treatment: A process conducted at elevated temperature and pressure in aqueous media to promote chemical reactions for contaminant removal.

References

1. Efficient reduction of Cr(VI) and recovery of Fe from chromite ore processing residue by waste biomass. Environmental Technology & Innovation (2023).
2. Upcycling of Cr-Containing Sulfate Waste into Efficient FeCrO3/Fe2O3 Catalysts for CO2 Hydrogenation Reaction. Materials (2024).
3. Enhancing the Immobilization of Hexavalent Chromium by the Interlayer Anion Adsorption of the Brucite-Transformed LDH in the Presence of Aluminum Ions. Sustainability (2023).