Abstract: Responses of bacterial community in polycyclic aromatic hydrocarbon (PAHs) contaminated soil remedied by reversal electric field were assessed by denaturing gradient gel electrophoresis (DGGE) and realtime quantitative PCR. The results showed that reversal electric field was favorable to the degradation of PAHs. The degradation rates of PAHs in the soils near the electrode and at electric field center were both more than 50%, especially in the soils at electric field center. During the remediation, bacteria 16S rRNA gene copy numbers and diversity indices of bacterial communities had no significant change between the soils near the electrode and at electric field center, and also showed no significant difference compared with the control. However, bacterial community structure showed obvious difference between the soils near the electrode and at electric field center, and had greater change compared with the control. The results suggested that changes in composition of bacterial community after application of electric field might be one of microbiological mechanisms of electro-enhanced bioremediation.

Key words: dye tracer experiment, stained path number, crack area density, soil surface characteristics.