Cleaning the Environment with Iron Nanoparticles

Roland Piquepaille writes "In "Nanoscale Iron Could Help Cleanse the Environment," the National Science Foundation (NSF) reports that "nanoscale" powder made from iron could be used to clean contaminated soil and water. "Iron's cleansing power stems from the simple fact that it rusts. When metallic iron oxidizes in the presence of contaminants, these organic molecules get caught up in the reactions and broken down into simple carbon compounds that are far less toxic." Using this technology, cleaning landfills or industrial sites would cost about $5 per square meter. More details are available in this summary, including other links and a diagram showing how the method works."

Comments

High risk of heat and hydrogen

[G4from128k]

I noticed a product called ThermaCare that uses an air-iron exothermic reaction to create a single-use heating pad. The description of the ingredients at ThermaCare's FAQ suggests some interesting and bad consequences of iron oxidation reactions. These include:
- the potential for generating uncontrolled levels of heat depending on the mix of iron, air, and accelerants.
- the potential for generating explosive hydrogen gas (in forming iron oxide from iron and water, hydrogen is left over).

Nanoscale iron reactions may well detoxify many pollutants. But high heat generation could volatilize solvents and explosions in and around contaminated soil don't seem wise either. I assume that some test samples would ensure that the soil was not too aerobic so that heat and hydrogen generation would be sufficiently gradual to forestall a dangerous reaction, but testing will always be imperfect.