To clean wastewater from munitions processing and demilitarization, engineers at the University of Delaware are testing a novel technology using iron nanoparticles. Instead of being corroded by oxygen in water, forming rust, the 25 nm iron particles are corroded by munitions compounds in wastewater.

The processing scheme is geared toward the degradation of insensitive munitions compounds used to replace more explosive constituents such as TNT. While these compounds are safer for personnel to handle, high solubility results in the presence of elevated concentrations in manufacturing effluents and other process The treatment process breaks down explosives in wastewater. Source: Joy Smokerwaters.

The iron nanoparticles donate electrons to these persistent munitions compounds, breaking them down through electron transfer mechanisms. The treatment scheme was demonstrated with wastewater samples from U.S. Army facilities with the addition of hydrogen peroxide to oxidize residues to harmless byproduct. During the process, the parent zero-valent iron transforms into di-valent iron, which activates the hydrogen peroxide to oxidize the compounds. Tri-valent iron is then generated to remove particles and residues and polish the treated wastewater for potential discharge or reuse.

The researchers note that this is the first use of iron nanoparticles to treat munitions wastewater, and that the technology might also prove applicable to the processing of effluents produced by agrochemical or consumer product manufacturing facilities.