Algae-removal performance of a fluidized-bed biofilm reactor system for lake water treatment.
The algae removal efficiency of a pilot plant--based on a fluidized-bed biofilm reactor system for treating--was investigated. This system does not require back-washing because the fluidized-bed suffers no clogging. Moreover, the system uses dissolved oxygen in the influent water for aerobic biological treatment without the need for additional aeration equipment. This, it is an easy-maintenance, low-energy system for purifying eutrophic lake water. The system was operated continuously at a flow rate of 1500 m3/d for nine months at Tsuchiura Port in Lake Kasumigaura. And concentrations of chlorophyll-a and dissolved oxygen in both the influent and effluent water were continuously monitored. In summer (August to September) when water bloom occurred, the average efficiency of chlorophyll-a removal was 64% at an average influent chlorophyll-a concentration of 137.8 micrograms/L. Over the entire experimental period of nine months, the average daily amount of removed chlorophyll-a was 40.3 g/d at an average influent chlorophyll-a concentration of 89.5 micrograms/L. By analyzing the relationship between the amount of removed chlorophyll-a and the consumption of dissolved oxygen, it was estimated that almost all of the algae trapped in the reactor was biologically degraded.
Tanaka
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T
Mechanical Engineering Research Laboratory, Hitachi Ltd., 502 Kandatsu, Tsuchiura, Ibaraki 300-0013, Japan.
Tsuzuki
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K
Nishijima
N
N
Takagi
T
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D018441:Biofilms; D002734:Chlorophyll / Q000378:metabolism*; D000077194:Chlorophyll A; D056890:Eukaryota / Q000502:physiology*; D005068:Eutrophication; D010100:Oxygen / Q000378:metabolism; D014876:Water Pollution / Q000517:prevention & control*; D014881:Water Supply
D002734:Chlorophyll; D010100:Oxygen; D000077194:Chlorophyll A