Contaminated water and soil at active or abandoned munitions plants is a serious problem since these compounds pose risks to human health and can be toxic to aquatic and terrestrial life. Our objective was to determine if zero-valent iron (Fe0) could be used to promote remediation of water and soil contaminated with 2,4,6-trinitrotoluene (TNT) and hexahyro-1,3,5-trinitro-1,3,5-triazine (RDX). As little as 1% Fe0 (w/v) removed 70 mg TNT litre-1 from aqueous solution within 8 h and removed 32 mg RDX litre-1 within 96 h. Treating slurries (1:5 soil:water) of highly, contaminated soil (5200 mg TNT and 6400 mg RDX kg-1 soil) from the former Nebraska Ordnance Plant (NOP) with 10% Fe0 (w/w soil) reduced CH3CN-extractable TNT and RDX concentrations below USEPA remediation goals (17.2 mg TNT and 5.8 mg RDX kg-1). Sequential treatment of a TNT-contaminated solution (70 mg TNT litre-1 spiked with 14C-TNT) with Fe0 (5% w/v) followed by H2O2 1% v/v) completely destroyed TNT and removed about 94% of the 14C from solution, 48% of which was mineralized to 14CO2 within 8 h. Fe0-treated TNT also was more susceptible to biological mineralization. Our observations indicate that Fe0 alone, Fe0 followed by H2O2, or Fe0 in combination with biotic treatment can be used for effective remediation of munitions-contaminated water and soil.
- Zero-valent iron
ASJC Scopus subject areas
- Health, Toxicology and Mutagenesis