US EPA

4123135 

Journal Article 

Laboratory Column Evaluation of High Explosives Attenuation in Grenade Range Soils 

Won, J; Borden, RC 

2017 

Yes 

Journal of Environmental Quality
ISSN: 0047-2425
EISSN: 1537-2537 

AMER SOC AGRONOMY 

MADISON 

46 

5 

968-974 

English 

28991974 

10.2134/jeq2017.05.0180 

WOS:000411433900005 

High explosives (HEs) deposited on military ranges can leach through the soil and contaminate groundwater. We examined the transport and fate of HEs in laboratory columns containing soils from two hand grenade bays (Bays C and T) and the impact of organic amendments on biodegradation. Soil characteristics were similar; however, Bay C had somewhat higher clay and organic C. Experimental treatments included addition of crude glycerin and lignosulfonate, and parallel control columns. Experimental results showed extensive 2,4,6-trinitrotoluene (TNT) degradation with minimal leaching, consistent with prior batch microcosm results. Amendment addition enhanced TNT degradation in both Bays C and T compared with controls. Although hexahydro-1,3,5-trinitro-1,3,5-triazine (Royal Demolition Explosive, or RDX) did not biodegrade in prior aerobic batch microcosms, 64 to 77% of RDX biodegraded in untreated soil columns with O present in the mobile soil gas. The RDX biodegradation was likely associated with short-term anoxic conditions or anoxic micro-niches. In nearly saturated Bay C columns, RDX removal increased to >92%. Amendment addition to unsaturated Bay T columns increased RDX removal to >86%. In one column, the soil remained anoxic (O < 5% by volume) for about a year after amendment addition, significantly reducing RDX leaching. Nitroso degradation products were produced equivalent to 9 to 39% of the RDX degraded, with most retained in the soil (9-37%) and 0 to 3% in the effluent. These results demonstrate that RDX biodegradation can occur in soils with measurable O, and that amendment addition can reduce RDX leaching by stimulating anaerobic biodegradation.