title: Algae-removal performance of a fluidized-bed biofilm reactor system for lake water treatment.
abstract: 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.
authors.affiliation: Mechanical Engineering Research Laboratory, Hitachi Ltd., 502 Kandatsu, Tsuchiura, Ibaraki 300-0013, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
authors.forename: K
authors.initials: K
authors.lastname: Tsuzuki
authors.forename: N
authors.initials: N
authors.lastname: Nishijima
authors.forename: T
authors.initials: T
authors.lastname: Takagi
mesh_terms: 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
chemical_list: D002734:Chlorophyll; D010100:Oxygen; D000077194:Chlorophyll A