In an effort to make the transportation and handling of munitions by military personnel safer, the United States Department of Defense (USDoD) is currently transitioning to utilizing insensitive high explosives (IHEs) in place of legacy or traditional munitions. As a result, the manufacturing, detonation, and disposal of new IHEs has resulted in insensitive munition compounds (IMCs) such as 2,4-dinitroanisole (DNAN), 3-nitro-1,2,4-triazol-5-one (NTO), 1-nitroguanidine (NQ), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), ammonium perchlorate (AP) and ammonium nitrate (AN), being released to the environment. Current treatment techniques are incapable of adequately treating water that has been contaminated with a mixture of IMCs due to their high chemical stability, low adsorptive capacities, and microbial toxicity. Furthermore, previous studies have shown that the biological treatment of DNAN and NTO requires sequential anaerobic and aerobic processes to completley mineralize them, which complicates biological treatment design and increases the input costs to applying full-scale treatment facilities. In this study, the mineralization of IMCs using high-rate aerobic and anaerobic sludge reactors is being evaluated. Defined redox zones embedded within the structure of granular sludge promote the conditions necessary for the simultaneous degradation of multiple IMCs in a single treatment step. We have demonstrated that anaerobic granular sludge is capapble of simultaneously reducing 94.2 ± 9.92% perchlorate and 99.9 ± 0.06% nitrate from a synthetic waste stream consisting of 500 mg/L perchlorate and 1,000 mg/L nitrate over 138 days of reactor operation. Additionally, we have also shown that aerobic granular sludge can simultaneously degrade 97.3 ± 3.02% DNAN, 56.6 ± 20.4% RDX, 94.9 ± 10.1% NTO, and 3.22 ± 5.18% NQ from a synthetic waste stream. The preliminary results of this study indictate that both aerobic and anaerobic sludge reactors are capable of treating water contaminated with a mixture of IHEs.

Biological degradation of legacy munitions and insensitive high explosives using aerobic and anaerobic granular sludge reactors

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.