RDX degradation using an integrated Fe(0)-microbial treatment approach

Area of Science:

• Environmental Science
• Environmental Chemistry
• Microbiology

Background:

• RDX (Royal Demolition Explosions) is a persistent and mobile groundwater contaminant.
• Remediation of RDX plumes at munitions facilities presents significant challenges.

Purpose of the Study:

• To evaluate permeable reactive iron barriers as a viable method for RDX plume interception and degradation.
• To investigate the role of anaerobic bacteria in enhancing RDX degradation by Fe(0).

Main Methods:

• RDX degradation was studied in aquifer microcosms amended with Fe(0) powder.
• Flow-through columns packed with steel wool were used to assess RDX reduction.
• Microbial enhancement of RDX degradation was investigated in anaerobic conditions.

Main Results:

• Fe(0) powder and steel wool rapidly reduced RDX in aquifer microcosms and columns.
• Anaerobic bacteria utilizing cathodic hydrogen (H2) enhanced RDX degradation rates and extent.
• Fe(0) treatment reduced RDX toxicity and improved its biodegradability.

Conclusions:

• Permeable reactive iron barriers show promise for RDX remediation.
• A combined Fe(0)-biological treatment approach can improve RDX removal efficiency.
• Enhanced biodegradation of RDX and its intermediates is achievable through this integrated method.