Environmental Engineering Reference
In-Depth Information
Genetically engineered microorganisms (GEMs) were developed that
were capable of using PCB congeners as growth substrate under aerobic
conditions. GEMs were modified to exhibit dechlorination genes that
enabled the removal of chlorine before chlorocatechols were formed, avoid-
ing toxicity (Tsoi et al., 1999). This approach avoids the need to manage
cometabolism, which can be difficult
in situ
. These organisms can be used
to remove products of anaerobic reductive PCB dechlorination, predomi-
nantly ortho-chlorinated and ortho- + para-chlorinated congeners (Hrywna
et al., 1999). Verniculite, as a carrier for the bacterial inoculum, improved
survival of the GEMs in Picatinny soil.
4.2 Technical approach
Figure 4.1 illustrates the technical approach used to develop new biotreat-
ment technologies during the Flask to Field project. The technical approach
within the consortium was to develop the most promising biotreatment
processes at the bench scale and then validate the technology at the pilot
and field scales. Engineering groups worked closely with scientists in eval-
uating the potential of the resulting technologies and in the transfer of
technologies from bench scale to field. The Technical Advisory Committee
(TAC) periodically reviewed projects for technical merit. The recommenda-
tions of these biotechnology experts to the thrust area coordinators served
to further enhance the projects. This approach ensured that effective reme-
diation technologies were developed within a reasonable time frame.
Chlorinated
Solvents
hPAHs
Explosives
PCBs
Process Engineering
CANDIDATES FOR DEMONSTRATION
AND VALIDATION
Figure 4.1
Biotreatment process development in Federal Integrated Biotreatment
Research Consortium (FIBRC).
