Environmental Engineering Reference
In-Depth Information
•
Characterize the PCB-growing variants of strains
Rhodococcus
sp.
RHA1 and
Burkholderia xenovorans
LB400 possessing hydrolytic
para-dechlorination (
fcb
) and oxygenolytic ortho-chlorobenzoate
(
ohb
) dechlorination genes, respectively, for their substrate range.
•
Evaluate the survivability of the recombinant PCB-growing organ-
isms RHA1(
fcb
) and LB400(
ohb
) and their impact on PCBs in soil
microcosms.
•
Evaluate the effect of FeSO
4
and FeS on the fate and activity of the
recombinant strains LB400(
ohb
) and RHA1(
fcb
) in soil microcosms.
•
Evaluate the survivability of introduced biphenyl-degrading bacteria
in soils.
•
Isolate and evaluate the feasibility of genetic enhancement of indig-
enous biphenyl-degrading organisms from the PCB-contaminated
soil to increase chances for successful PCB remediation in this envi-
ronment, which has a complex contamination profile.
6.2.3
Research objectives to enhance PCB remediation
•
Investigate the growth of
Comamonas testosteroni
VP44 and
Rhodococ-
cus erythreus
NY05 on biphenyl and 4-chlorobiphenyl (4-CBP) in the
presence of selected nonionic surfactants (Tween 80, Tergitol NP-15,
and Witconol SN-120).
•
Develop analytical methods (high-performance liquid chromatogra-
phy (HPLC) and gas chromatography (GC)) to measure the concen-
tration of both surfactant and PCB congeners in the aqueous phase.
•
Measure the rates of micellar solubilization and equilibrium solubi-
lization capacity of the selected surfactant for specific PCB congeners.
•
Measure the sorption and desorption of surfactants on natural soils
possessing a range of organic carbon (OC) contents (Wurtsmith aqui-
fer material, 0.02% OC; Appling soil, 0.7% OC; and Webster soil, 3.5%
OC) and the influence of surfactant sorption on PCB sorption by the
solid phase.
•
Quantify the aerobic degradation of both surfactant and PCB conge-
ners in aqueous systems by recombinant variants of
Comamonas tes-
tosteroni
VP44 and
Rhodococcus erythreus
NY05.
•
Conduct microcosm experiments (500-ml reactors) to assess the de-
sorption and aerobic dechlorination of sorbed-phase PCB congeners
in the presence of Tergitol NP-15 and Tween 80.
•
Develop and test a mathematical model to describe the coupled
sorption/desorption, micellar solubilization, and transformation of
PCB congeners under sequential anaerobic and aerobic conditions.
•
Investigate the growth of
Comamonas testosteroni
VP44 and
Rhodococ-
cus erythreus
NY05 on biphenyl and 4-CBP in the presence of selected
nonionic surfactants (Tween 80, Tergitol NP-15, and Witconol
SN-120).
