This control experiment proved that the absence of PCBs was as a result of bacteria degrading the compounds. In this control the wastewater was first sterilised by autoclaving. The chromatogram results obtained were similar to the one obtained with the standard. This was a confirmation that the changes obtained in regard to the compound Aroclor 1260 added to wastewater in the presence of bacteria isolate MD2 was a result of biodegradation of the compound by the isolate.

Figure 4: HPLC Chromatogram for PCB degradation in sterilised wastewater with no inoculation (Control 2).