The Sequential Anaerobic-Aerobic Biodegradation Of PCBs In Phytoremediation Cuttings

Abstract

The sequential anaerobic-aerobic process was applied for PCB biodegradation from plant cuttings. The PCBs were absorbed by plant roots called phytoextraction. The anaerobic process dechlorinated highly chlorinated PCBs (tetra-, penta-, hexa-) to lower chlorinated PCBs (mono-, di-, tri-). Then, the aerobic cultures degraded the low chlorinated PCBs. In the experiment, Aroclor 1254, the commercial PCB mixtures, were used. The culures were fed by methanol (CH4) as a sole carbon source. The temperature was an essential parameter to control the dechlorinated state. Produced gas from the anaerobic process was collected to examine the anaerobic condition. The highly chlorinated PCBs were dechlorinated with different pathways dependent upon the dominant cultures in the process. The PCB dechloriantion was detected by gas chromatography and reported by chromatograms. The phytoabsorption showed difficulty of PCB biodegradation. The PCB removal efficiency was compared with the PCB removal from contaminated soil of the previous study.