Removal of RDX from a Contaminated Groundwater by In Situ Bioremediation

摘要

Controlled experiments involving biodegradation of RDX were conducted with 14C-tagged RDX in aerobic, an- aerobic, and anaerobic/aerobic slurries to identify the conditions maximizing RDX-mineralization. Indigenous- microorganisms present in the CAAP groundwater and soil were evaluated along with a consortium of three microbes isolated from Hastings soil under aerobic conditions. A culture collection bacterium reported to be able to degrade RDX under anaerobic conditions was also evaluated. Several different carbon supplements were also investigated. Highest degree of mineralization (50%) was obtained under aerobic conditions when the contaminated groundwater was supplemented with large quantities of carbon source and Hastings triplet. Anaerobic/aerobic operation with native CAAP organisms and potato starch also resulted in rapid mineralization during the aerobic phase of the experiment. Under suitably chosen conditions, it was possible to transform RDX in solution to non-detect levels.