The Study On The Manufacture, Character And Modification Of Polyaniline (PANI)-biofilm Composite Biocathode

Based on the stability and effect on human body of perchlorate, and take the various methods for perchlorate removement into consideration, we prepared a polyaniline (PANI)-biofilm composite biocathode for perchlorate removement. And at the same time, a permanent potential is applied to the composite biocathode to promote the conglomerate of the perchlorate reducing bacteria (PRB).Cyclic voltametric technique, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), Fluorescent in situ hybridization (FISH), polymerase chainreaction-denaturing gradient gel electrophoresis (PCR-DGGE) was used to study the performance of the composite biocathode.This study showed that the composite biocathode which was manufactured base on the wax-impregnated graphite electrode had good reduction for the perchlorate.The EIS (E=0.05V) result showed that the calculated reaction rate for the perchlorate is5.46×10-10mol/s (about3cm2), the FISH result showed that external electric field has a good effect on the perchlorate reducing bacteria’s enrichment in the biofilm, and pili was observed between the bacteria and the composite biocathode,which was used to help the bacteria attach to the composite biocathode and promote the electron translation.FISH result showed that external electric field has a good effect on the perchlorate reducing bacteria’s enrichment in the biofilm,a PCR-DGGE experimentation was carried to know the change of community in the bacteria in the sludge. The result showed that the bacteria on the composite biocathode was less that that in the sludge, Besides one new PRB may be discovered.Sodium dodecyl sulfate (SDS) was used to modify the PANI to improve the porous structure of the PANI, in order to improve the amount of PRB on the composite biocathode, which to be improved resultful because more bacteria was observed in the SEM picture.