Difference between revisions of "Iron filings (ZVI)"
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===How is it being used?=== | ===How is it being used?=== | ||
| − | No projects that use ZVI were found in Ontario. | + | * A Maplewood,Minnesota field study developed an iron-enhanced (5% iron filings) ditch check sand filter for installation in [[Swales|swales]] to provide treatment of dissolved heavy metals and dissolved phosphorous in stormwater runoff from highways<ref>Farzana Ahmed, Poornima Natarajan, John S. Gulliver, Peter T. Weiss, John L. Nieber. 2014. Assessing and Improving Pollution Prevention by Swales. https://www.lrrb.org/pdf/201430.pdf</ref>. |
| + | * No projects that use ZVI were found in Ontario. | ||
[[File:Screenshot 2025-08-13 113919.png|500px|thumb|[[Bioretention]] schematic, with circles highlighting ZVI addition and phosphorus removal <ref name = Lechner>Lechner L. Phosphorus Removal From Stormwater Using Zero-Valent Iron. 2016. Applied Science Masters Thesis.</ref>.]] | [[File:Screenshot 2025-08-13 113919.png|500px|thumb|[[Bioretention]] schematic, with circles highlighting ZVI addition and phosphorus removal <ref name = Lechner>Lechner L. Phosphorus Removal From Stormwater Using Zero-Valent Iron. 2016. Applied Science Masters Thesis.</ref>.]] | ||
Revision as of 18:56, 13 August 2025
What is it?[edit]
Iron filings or zero-valent iron (ZVI) is the elemental form of iron with a zero charge carried by each atom – a result of the outer valence level being filled. ZVI is able to remove dissolved phosphorus (phosphate) from solution through precipitation. [1] Zero-valent iron nanoparticles (nZVI) are also used for phosphorus removal.
How is it being used?[edit]
- A Maplewood,Minnesota field study developed an iron-enhanced (5% iron filings) ditch check sand filter for installation in swales to provide treatment of dissolved heavy metals and dissolved phosphorous in stormwater runoff from highways[2].
- No projects that use ZVI were found in Ontario.
Benefits[edit]
A study was done that compared the phosphorus reduction capabilities of ZVI, biochar, biochar-supported ZVI (ZVI/BC), and biochar-supported nZVI (nZVI/BC). [1] It was found that nZVI/BC had the highest phosphorus reduction. Using biochar-supported ZVI or nZVI improves the dispersion and stability of the iron filings. Biochar is fine-grained and highly porous, providing a large surface area to support nZVI. Another paper reports that ZVI can remove up to 98% of influent phosphorus at low input concentrations, and at high concentrations is shown to remove up to 36% of incoming phosphorus. The phosphorus retained in the soil is mostly iron-bound, which will not be easily leached out of the system because it is very stable.[3]
Back to additives.
- ↑ 1.0 1.1 Rossetti M. Evaluation of phosphorous removals by biochar supported nano-scale zero-valent iron. 2017. Chemical Engineering Undergraduate Honors Thesis.
- ↑ Farzana Ahmed, Poornima Natarajan, John S. Gulliver, Peter T. Weiss, John L. Nieber. 2014. Assessing and Improving Pollution Prevention by Swales. https://www.lrrb.org/pdf/201430.pdf
- ↑ 3.0 3.1 Lechner L. Phosphorus Removal From Stormwater Using Zero-Valent Iron. 2016. Applied Science Masters Thesis.