Effect of Surfactant SDS, Tween 80, Triton X-100 and Rhamnolipid on Biodegradation of Hydrophobic Organic Pollutants

The effects of synthetic surfactants SDS, Tween 80, Triton X-100 on bacteria Flauobacteriurn sp. Q14 capable of degrading gasoline were studied. Biosurfactant rhamnolipid was used to analyze the effect on the biodegradation of n-hexadecane and the cell surface hydrophobicity for Bacillus sp. DQ02. The results showed that all the three chemical surfactants could delay the logarithmic phase of Flauobacteriurn sp. Q14. The anionic surfactant SDS did not significantly increase the degradation rate of diesel both at day 2 and 4. The maximum degradation value was 42.2% and 44.5% at 100 mg/L in the presence of Triton X-100 and Tween 80, respectively. The removal efficiency declined with the increase of concentration of surfactants over 100 mg/L. At day 4, the maximum degradation value reached 44.7% and 46.3% at 200 mg/L. The degradation of n-hexadecane by Bacillus sp.DQ02 was increased 11.6% within 48 h in the presence of the rhamnolipid than that of in the absence of the rhamnolipid. The growth of the strain and BATH (bacterial adherence to hydrocarbon) increased with obviously in the presence of the rhamnolipid. And the BATH reached 44% in the presence of rhamnolipid. Moreover, the interfacial tension decreased almost half with the addition of rhamnolipid.