title: Seasonal variation of microcystin concentrations in the Saint-Caprais reservoir (France) and their removal in a small full-scale treatment plant.
abstract: At the Saint-Caprais reservoir (France), a mono-specific bloom of Aphanizomenon flos-aquae occurs every year in the autumn months. Levels of microcystin-LR (MCYST-LR) in this reservoir were evaluated by protein phosphatase type 2A (PP2A) inhibition test as MCYST-LR equivalents in both raw and drinking water. Analysis by HPLC of the crude extract of the mono-specific bloom of A. flos-aquae revealed the presence of MCYST-LR with a low concentration of 270.3 +/- 20.4 ng/g wet weight. MCYST-LR equivalent concentrations in raw water were correlated with the cyanobacteria biomass and they varied between 14 and 74 ng/l. The removal of A. flos-aquae and microcystins were evaluated in a small full-scale plant associated with the Saint-Caprais reservoir. Total elimination of cyanobacterial cells and the low concentration of hepatotoxins was achieved through the combined action of pre-ozonation at 0.07 mg/l and adsorption on powdered activated carbon at 20 mg/l. However, pre-chlorination at 0.42 mg/l followed by 20 mg/l of powdered activated carbon removed only 45% of hepatotoxins.
authors.affiliation: Laboratoire Santé Publique-Environnement, Université Paris-Sud, UFR de Pharmacie, Châtenay-Malabry, France.
authors.forename: Imed
authors.initials: I
authors.lastname: Maatouk
authors.forename: Noureddine
authors.initials: N
authors.lastname: Bouaïch
authors.forename: Didier
authors.initials: D
authors.lastname: Fontan
authors.forename: Yves
authors.initials: Y
authors.lastname: Levi
mesh_terms: D017033:Anabaena; D001427:Bacterial Toxins / Q000032:analysis*; D018533:Biomass; D002244:Carbon; D000458:Cyanobacteria; D004202:Disinfectants; D004784:Environmental Monitoring; D004791:Enzyme Inhibitors / Q000032:analysis*; D005068:Eutrophication; D005602:France; D008387:Marine Toxins; D052998:Microcystins; D010456:Peptides, Cyclic / Q000032:analysis*; D011157:Population Dynamics; D012621:Seasons; D018508:Water Purification; D014881:Water Supply
chemical_list: D001427:Bacterial Toxins; D004202:Disinfectants; D004791:Enzyme Inhibitors; D008387:Marine Toxins; D052998:Microcystins; D010456:Peptides, Cyclic; D002244:Carbon; C057862:cyanoginosin LR