Decomposition of Nitroglycerin in Smokeless Powders by Aerobic Thermophilic Composting
The reported study evaluated the disappearance of nitroglycerin as applied in commercial smokeless powder (SP), in compost prepared from vegetative matter. Double base smokeless powder was applied to mesocosms at rates of 0, 1 and 5% (w/w) and mesocosms were incubated for 70 d. Compost was prepared at two moisture levels, viz., 20.5 bar and 20.1 bar (wet and moist, respectively). Amendments to microcosms included agricultural limestone and alkaline powerplant fly ash. Determination of free NG was performed using gas chromatography with electron capture detection. In wet compost, NG concentrations decreased by 72% from Day 7 to Day 35. In contrast, NG in moist compost exhibited significantly ( p < 0.05) less NG solubilization and decomposition. Compost nitrate levels increased markedly after 28 d incubation; however, no correlation was determined between NG concentrations and NO3 levels or compost pH. Incorporation of limestone or fly ash had no marked impact on NG disappearance. Destruction of NG appears to be substantially more rapid via thermophilic composting compared with incubation in soil, and should serve as a low-cost, viable technology for NG-contaminated media.