and were shaken for 48 h at 20°C on a rotary shaker (125 rpm). The solutions were then filtered to separate the crystalline portion of the PAHs. The solutions were immediately added to the NMB solution, which contained micro-organisms acclimatised to phenanthrene, in order to prevent the loss of PAHs from volatilization. The reaction solution was sampled at set time intervals and the samples were filtered through 0.2 μm filter paper. The filtered solution was analyzed for naphthalene and phenanthrene using HPLC.