Slide Image: An illustration shows how an ultrafine, "nanoscale" powder made from iron, one of the most abundant metals on Earth, is an effective tool for cleaning up contaminated soil and groundwater (site remediation with iron nanoparticles).
In the image a horizontal line is near the top to indicate ground level. A contaminant source is shown on the upper left side above and below ground level. Lines lead down from the contamination source to a large puddle-shaped area indicating leaching of the contaminant into the ground. Just to left of center and descending from ground level into the contamination area is a vertical tube into which iron nanoparticles are injected. Once the iron nanoparticles are injected and released in the contamination site (indicated by arrows pointing out from the bottom third of the tube), they break down the following contaminants into less toxic compounds, each illustrated by a star-like shape:
Dechlorination of Organic Solvent (e.g., CCl4, C2Cl4)
Detoxification of Pesticides (e.g., Lindane, DDT)
Transformation of Fertilizers (e.g., NO3-)
immobilization of Metals (e.g., Pb, Cr, As).
On the right side of the illustration is another vertical tube that goes from above ground level down to the lowest level of contamination. An arrow points up from the top of the tube. The bottom half of the tube is dark.
Credit: Wei-Xian Zhang, Lehigh University