Ref ID : 1099
Yoshihara Kazutoshi, Okubo Teturou, Fujio Yusaku, and Ueda Seinosuke; Growth of biofilm in initial operational stage of a biofilter. Hakkokogaku 57(6):475-481, 1979
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Taking into consideration adhesive growth on the filter media, COD removal activity and floc formation, four bacterial strains were selected as the seed source for a packed biofilter. One of them isolated from the biofilm grew well not only on glass filter media but also on synthetic polymer media such as polypropylene and foamed polystyrene. This strain was identified as genus Flavobacterium and considered effective as the main seed source of the biofilter. Eight biofilters (2 m in height and 100 mm in dia.) packed with polypropylene media (25 mm in dia.) were individually inoculated with eight seed systems which were all composed of combinations containing Flavobacterium sp. S78. The more strains the seed was composed of, the more rapidly the COD removal capacities of biofilters increased. When the inoculation was stopped, there were some biofilters of which the COD removal capacities decreased. Bacteria resembling Flavobacterium sp. S78 in morphological characteristics were isolated most frequently from the growing biofilm of the four strains used as the seed, followed by Vibrio sp. A6. Bacteria resembling both Pseudomonas sp. U52 and unidentified strain S102C which had been isolated from activated sludge and acclimated sludge, respectively, were not dominant in the biofilm. The biofilm developed uniformly around the filter media in five biofilters. In the other three, media were covered with colonial or dappled growths perhaps due to the Vibrio sp. A6 contained in the biofilm. After 6 days, 530 to 1180 mg dry biomass was obtained per liter of biofilter and this value was almost equal to that of mixed liquor suspended solid in the aeration tank of the conventional activated sludge system.