PROGRESS TOWARD THE BIOLOGICAL TREATMENT OF C(1) AND C(2) HALOGENATED HYDROCARBONS

Halogenated aliphatic hydrocarbons can be dehalogenated and completely mineralized in a highly reductive environment characterized by active methanogenesis. In the aerobic environment, microbial growth on certain alkanes and aromatic compounds induces the synthesis of mono- and dioxygenases, which fortuitously oxidize and dehalogenate alkanes and alkenes. Tetrahalogenated methanes, ethanes, and ethenes are readily reduced under anaerobic conditions, but they are not known to be degraded by aerobic microorganisms. In contrast, less halogenated compounds are more easily degraded aerobically. Development of a sequential anaerobic-aerobic bioreactor process for the complete mineralization of these hazardous wastes at source is recommended as a feasible and preferable alternative to current disposal methods.