Iron-mediated remediation of RDX-contaminated water and soil under controlled Eh/pH

Journal Article · Sat May 01 04:00:00 EDT 1999 · Environmental Science and Technology

DOI:https://doi.org/10.1021/es9806175· OSTI ID:354353

Singh, J; Comfort, S D; Shea, P J ^[1]

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1. Univ. of Nebraska, Lincoln, NE (United States). School of Natural Resource Sciences

Soil and water contaminated with hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a serious environmental problem at several active and abandoned munitions production facilities. Zero-valent iron (Fe{sup 0}) can effectively remediate RDX-contaminated soil and water. The objective of this study was to manipulate Eh and pH for enhanced Fe{sup 0}-mediated destruction of RDX. This was accomplished by monitoring RDX destruction under controlled Eh-pH conditions (Eh: {minus}300 to +150 mV; pH: 2--10). Decreasing Eh and pH increased RDX destruction in aqueous solution. Treating 20 mg of RDX L{sup {minus}1} (90 {micro}M) under a static Eh of {minus}150 mV and pH 7 with 20 g of Fe{sup 0} L{sup {minus}1} removed 95% of the RDX within 4 h; no RDX was detected after 8 h. Treating a soil slurry (20% solids; 510 mg RDX kg{sup {minus}1} soil) with 20 g of Fe{sup 0} L{sup {minus}1} at an Eh of {minus}150 mV and pH 7 increased RDX destruction by 24% over the unbuffered control and resulted in 99% RDX destruction within 24 h. Adding 4.2 mM sodium sulfide (in lieu of a static Eh) under similar conditions resulted in 93% RDX loss within 24 h. Results indicated that lowering Eh and maintaining neutral pH during Fe{sup 0} treatment can increase RDX destruction in contaminated soil and water.

• OSTI ID: 354353
• Journal Information: Environmental Science and Technology, Journal Name: Environmental Science and Technology Journal Issue: 9 Vol. 33; ISSN 0013-936X; ISSN ESTHAG
• Country of Publication: United States
• Language: English

Related Subjects

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
54 ENVIRONMENTAL SCIENCES
EXPLOSIVES
GROUND WATER
IRON
NITRO COMPOUNDS
PH VALUE
REDOX POTENTIAL
REMEDIAL ACTION
SOILS