광합성세균에 의한 미생물막의 형성 = Formation of Microbial Films with Phototrophs in a Packed-Bed Reactor

국문 초록 (Abstract)

홍색비유황 광합성세균인 Rhodopseudomonas capsulata를 선택하여 packed-bed reactor에서 미생물막을 형성할 때, porous ceramic bead가 다른 담체에 비해 우수하였고, 일정한 유입농도하에서 체류시간(hydraulic retention tiem, HRT)이 짧을수록 미생물막 형성이 양호하였으며, 그 때 반응기내의 세포농도는 11,400mg/l로 현탁처리시의 세포농도에 비하여 3~8배 증가하였다. PBR에서 미생물막의 형성은 cell attachment, microcolony formation, biofilm formation의 단계를 거쳐 형성되는 것으로 관찰되었으며, PBR이 FBR보다 안정적인 미생물 부착을 보였고 특히 PBR에서는 BOD용적 부하가 15gBOD/ℓ·day 이상이 되어도 미생물막의 부착비율은 90% 이상을 유지하였다. 전자현미경으로 담체의 표면 및 내부에 고정화된 광합성세균을 확인할 수 있었다.

다국어 초록 (Multilingual Abstract)

The formation of microbial films(biofilm) by a non-sulfur phototrophic bacteria, Rhodopseudomonas capsulata, on inorganic media was studied. Porous ceramic beads(PCB) were superior to other immobilizing media for the biofilm formation in a packed-bed reactor. It was found that the formation of microbial films favored a lower hydraulic retention time, showing a higher ratio of cells attatched to the media to those suspended in the solution. The cell concentration in the biofilm reactor was as high as 11,400 mg/ℓ, which is 8-folds of the cell concentration in a ordinary suspended treatment. It was observed that the formation of microbial film by R. capsulata followed a general serial process of cell attachment, microcolony formation, and biofilm formation. The microbial films thus formed was very stable even for an extremely high volumetric BOD loading rate of 15 gBOD/ℓ·day. The scanning electron micrographs of the microbial films showed that the cells were attached to both the surface and pores of the media.