title: Degradation of aroclor 1242 in a single-stage coupled anaerobic/aerobic bioreactor.
abstract: Degradation of Aroclor 1242 was studied in granular biofilm reactors with limited aeration. An aerobic biphenyl degrader, Rhodococcus sp. M5, was used to supplement a natural bacterial population present in a "bioaugmented" reactor, while the "non-bioaugmented" reactor only contained natural granular sludge. The bioaugmentation, however appeared to have no effect on the reactor performance. Aroclor measurements showed its disappearance in both reactors with only 16-19% of Aroclor recovered from the reactor biomass and effluent. Simultaneously, a chlorine balance indicated that dechlorination occurred at a specific rate of 1.43 mg PCB (g volatile suspended solids)(-1) d(-1), which was comparable to the observed rate of Aroclor disappearance. Intermediates detected in both reactors were biphenyl, benzoic acid, and mono-hydroxybiphenyls. This suggests that a near-complete mineralization of Aroclor can be achieved in a single-stage anaerobic/aerobic system due to a combination of reductive and oxidative degradation mechanisms.
authors.affiliation: Biotechnology Research Institute, Montreal, Quebec, Canada.
authors.forename: B
authors.initials: B
authors.lastname: Tartakovsky
authors.forename: A
authors.initials: A
authors.lastname: Michott
authors.forename: J C
authors.initials: JC
authors.lastname: Cadieux
authors.forename: J
authors.initials: J
authors.lastname: Hawari
authors.forename: S R
authors.initials: SR
authors.lastname: Guiot
mesh_terms: D001140:Aroclors / Q000378:metabolism*; D001420:Bacteria, Aerobic / Q000502:physiology; D001421:Bacteria, Anaerobic / Q000502:physiology; D018441:Biofilms; D019149:Bioreactors; D004785:Environmental Pollutants / Q000378:metabolism*; D010084:Oxidation-Reduction; D012240:Rhodococcus / Q000502:physiology*; D018508:Water Purification
chemical_list: D001140:Aroclors; D004785:Environmental Pollutants; C027423:aroclor 1242