Effect of hydrogen peroxide on the biodegradation of PCBs in anaerobically dechlorinated river sediments

The ability to initiate aerobic conditions in dechlorinated anaerobic sediments was tested using hydrogen peroxide as an oxygenation agent. Hydrogen peroxide additions to the sediment induced aerobic polychlorinated biphenyl (PCB) degraders as indicated first, by an increase in bacterial count and second by a decline in PCB concentration from 135 micrograms/g to 20 micrograms/g over a 96-day period. Dechlorinated anaerobic sediment seems also to harbor indigenous anaerobic and aerobic microorganisms with high PCB degradation abilities. Those results support the potential of in situ degradation of PCBs using a sequential anaerobic-aerobic technique.