Figure 3.

PCB_i accumulation in the vapor phase (left) and free aqueous phase (right) over the 35-day incubation period. Vapor phase profiles reveal that LB400 prevented 59% of the PCBs shown here from volatilizing. A small number of congeners were particularly resistant to biodegradation (e.g., PCBs 10,19, 32). Aqueous phase PCB profiles show a proportional decrease in freely dissolved concentrations for those congeners that volatilized. Taken together, these results indicate that LB400 biotransformed freely dissolved LC-PCBs as they desorbed from sediment particles and prevented them from volatilizing. The T = 16 days SPME measurement in the control is likely elevated due to small-scale sediment heterogeneity. The error bars represent the standard error of triplicate measurements in non-bioaugmented controls (n = 3) and quadruplet in bioaugmented treatments (n = 4).