抄録
This paper describes the structure and characteristics of granules which were unexpectedly formed in anaerobic-oxic activated sludge process. The activated sludge granules had prominent characteristics of sedimentation and agglomeration : sedimentation velocity was 13-15cm·min-1 ; sludge volume for 30 minutes was 6% ; sludge volume index was 27ml·g-1. The surface structure of the granules was densely agglomerated by various bacteia, mainly rod type bacteria. Some parts of its surface were covered by extracellular polymer, and other parts showed the complex structure with multi-layers. By the quantitical analysis of chemical compositions of the granules, the contents of Fe, Zn and Ca in the granules were found to be more than those of activated sludge. The microflora of granules was characterized using quinone profile. In the granules, Rhodoquinone-8 (RQ-8) of 1.8mol% was detected, while little RQ-8 was found in activated sludge. This result suggested that bacteria containing RQ-8 would participate in formation of the granules.
