Fate of CL-20 in sandy soils: Degradation products as potential markers of natural attenuation

• Published in: Environmental pollution (1987) 2009, Vol.157 (1), p.77-85
• Main Authors: Monteil-Rivera, Fanny, Halasz, Annamaria, Manno, Dominic, Kuperman, Roman G., Thiboutot, Sonia, Ampleman, Guy, Hawari, Jalal
• Format: Article
• Language: English
• Subjects: Abiotic degradation; Applied sciences; Aza Compounds - analysis; Aza Compounds - chemistry; biodegradation; Biodegradation, Environmental; Biological and physicochemical properties of pollutants. Interaction in the soil; Biotic degradation; CL-20; degradation; Degradation products; denitrification; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; environmental fate; Environmental Monitoring - methods; Exact sciences and technology; Explosive Agents - analysis; Explosive Agents - chemistry; explosives; Heterocyclic Compounds - analysis; Heterocyclic Compounds - chemistry; hydrolysis; Natural attenuation; Pollution; Pollution, environment geology; sandy soils; Silicon Dioxide; Soil - analysis; Soil and sediments pollution; Soil Microbiology; Soil Pollutants - analysis; Soil Pollutants - chemistry; soil pollution
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2008.07.030

Hexanitrohexaazaisowurtzitane (CL-20) is an emerging explosive that may replace the currently used explosives such as RDX and HMX, but little is known about its fate in soil. The present study was conducted to determine degradation products of CL-20 in two sandy soils under abiotic and biotic anaerobic conditions. Biotic degradation was prevalent in the slightly acidic VT soil, which contained a greater organic C content, while the slightly alkaline SAC soil favored hydrolysis. CL-20 degradation was accompanied by the formation of formate, glyoxal, nitrite, ammonium, and nitrous oxide. Biotic degradation of CL-20 occurred through the formation of its denitrohydrogenated derivative ( m/ z 393 Da) while hydrolysis occurred through the formation of a ring cleavage product ( m/ z 156 Da) that was tentatively identified as CH 2 N–C( N–NO 2)–CH N–CHO or its isomer N(NO 2) CH–CH N–CO–CH NH. Due to their chemical specificity, these two intermediates may be considered as markers of in situ attenuation of CL-20 in soil. Two key intermediates of CL-20 degradation are potential markers of its natural attenuation in soil.