In Situ Stimulation of Aerobic PCB Biodegradation in Hudson River Sediments

Abstract

A 73-day field study of in situ aerobic biodegradation of polychlorinated biphenyls (PCBs) in the Hudson River shows that indigenous aerobic microorganisms can degrade the lightly chlorinated PCBs present in these sediments. Addition of inorganic nutrients, biphenyl, and oxygen enhanced PCB biodegradation, as indicated both by a 37 to 55 percent loss of PCBs and by the production of chlorobenzoates, intermediates in the PCB biodegradation pathway. Repeated inoculation with a purified PCB-degrading bacterium failed to improve biodegradative activity. Biodegradation was also observed under mixed but unamended conditions, which suggests that this process may occur commonly in river sediments, with implications for PCB fate models and risk assessments.

Degradation of Aroclor 1242 Dechlorination Products in Sediments by Burkholderia xenovorans LB400( ohb ) and Rhodococcus sp. Strain RHA1( fcb )

“…Thus, the primary advantage of PCB-growing strains is that the maintenance of an adequate PCB-degrading population should occur and would avoid either the repeated inoculation of strains into the contaminated site (12) or the use of a second carbon source to stimulate cometabolism, such as biphenyl (2,13), surfactants (20,21), or plant aromatic compounds (11). For this approach to be successful, however, the plasmid constructs must remain stable, which was the case over the course of our experiment (Fig.…”

Three Stages of a Biofilm Community Developing at the Liquid-Liquid Interface between Polychlorinated Biphenyls and Water

“…Despite the fact that a number of PCB-degrading bacteria are known, this pollutant is recalcitrant in the environment, and efforts at bioremediation with optimized strains were often not very successful (11). To improve intrinsic bioremediation, a passive remedial approach that depends on microbial processes to degrade and dissipate pollutants in soil and groundwater, one has to understand the influence of this highly hydrophobic substrate on the autochthonous microbial community.…”

Natural and accelerated bioremediation research program plan

“…In addition, several projects, including one at DOE'S Savannah River Site, have demonstrated that TCE can be co-metabolically degraded in situ by providing methane as a carbon source. Explosives and polychlorinated biphenyls (PCBs) have been biodegraded in field-scale experiments (Harkness et al, 1993). Bacterial transformation and immobilization of trace metals such as selenium also have been implemented on a limited basis (Benson et al, 1993).…”