title: Removal of cyanobacteria, cyanotoxins, heterotrophic bacteria and endotoxins at an operating surface water treatment plant.
abstract: The removal of cyanobacteria, hepatotoxins produced by them (microcystins), phytoplankton, heterotrophic bacteria and endotoxins were monitored at a surface water treatment plant with coagulation, clarification, sand filtration, ozonation, slow sand filtration and chlorination as the treatment process. Coagulation-sand filtration reduced microcystins by 1.2-2.4, and endotoxins by 0.72-2.01 log10 units. Ozonation effectively removed the residual microcystins. The treatment process reduced phytoplankton biomass by 2.2-4.6 and heterotrophic bacteria by 2.0-5.0 log10 units. In treated water, the concentration of microcystins never exceeded the WHO guide value (1 microg/L), but picoplankton and monad cells were often detected in high numbers. The heterotrophic bacterial isolates from the treated waters belonged to genera Sphingomonas, Pseudomonas, Bacillus, Herbaspirillum and Bosea.
authors.affiliation: Finnish Environment Institute, PO Box 140, FIN-00251 Helsinki, Finland. jarkko.rapala@sttv.fi
authors.forename: J
authors.initials: J
authors.lastname: Rapala
authors.forename: M
authors.initials: M
authors.lastname: Niemelä
authors.forename: K A
authors.initials: KA
authors.lastname: Berg
authors.forename: L
authors.initials: L
authors.lastname: Lepistö
authors.forename: K
authors.initials: K
authors.lastname: Lahti
mesh_terms: D001419:Bacteria / Q000145:classification / Q000302:isolation & purification*; D000458:Cyanobacteria / Q000302:isolation & purification*; D004731:Endotoxins / Q000302:isolation & purification*; D013045:Species Specificity; D014871:Water Microbiology; D014881:Water Supply
chemical_list: D004731:Endotoxins