Bioaugmentation for Remediation of Chlorinated Solvents: Technology Development, Status, and Research Needs
ENVIRONMENTAL SECURITY TECHNOLOGY CERTIFICATION PROGRAM ALEXANDRIA VA
Pagination or Media Count:
The intent of this White Paper is to summarize the current technical and regulatory status of bioaugmentation, and to identify research needs to be addressed in upcoming years to facilitate widespread successful use of the technology. The focus of the White Paper is on bioaugmentation for chlorinated ethenes, as this is a critical need for the Department of Defense DoD and because of the advanced application and commercialization of bioaugmentation cultures for these compounds. Research in the early 1980s provided the first evidence that common chlorinated solvents such as tetrachloroethene PCE, trichloroethene TCE, 1,1,1-trichloroethane 1,1,1-TCA and carbon tetrachloride CT could be biodegraded by microorganisms that are naturally present in soil and groundwater. However, until the recent development of rapid and inexpensive molecular techniques for microbial identification, little was known regarding the specific microorganisms mediating these biodegradation reactions. As a result, an entire bioremediation industry developed for the remediation of chlorinated solvents in soil and groundwater without a comprehensive understanding of the relevant microbiological processes involved, including the identities of the bacteria mediating the degradation reactions, their nutrient requirements, and the appropriate methods for stimulating the desired degradation reactions while minimizing competitive or undesirable microbial activities. In the late 1980s and early 1990s, the growing acceptance of bioremediation to treat petroleum hydrocarbons and wood preserving wastes led to a proliferation of vendors offering microbial inoculants for bioaugmentation. However, experience showed that many of these inocula were not effective under field conditions, and the process of bioaugmentation fell into disrepute.
- Environmental Health and Safety