title: Micro-organism re-growth in wastewater disinfected by UV radiation and ozone: a micro-biological study.
abstract: A series of disinfection experiments using UV radiation and ozone was performed on the secondary effluent from a wastewater treatment plant at a pilot plant scale. The microbial population in the inflowing wastewater and the treated outflow water were quantified for each of the treatment modules (fecal coliforms, fecal streptococci, Salmonella spp. (presence/absence), Clostridium Sulphite-reducers, Pseudomonas aeruginosa, Staphylococcus aureus, coliphages, nematodes, intestinal nematodes and pathogenic fungi). Treated water was stored in opaque tanks at a temperature between 20 and 22 degrees C, after which, a one-month study of the regrowth of the bacterial flora, nematodes and fungi was carried out. Clostridium Sulphite-reducers, pathogenic fungi and nematodes were the micro-organisms showing a greatest degree of resistence to UV- and Ozone-treatment. It was only concerning Clostridium and Pseudomonas abatement that significant elimination results were achieved with both technologies.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University of Seville, E-41012, Seville, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Alonso
authors.forename: A
authors.initials: A
authors.lastname: Santos
authors.forename: P
authors.initials: P
authors.lastname: Riesco
mesh_terms: D003013:Clostridium / Q000187:drug effects / Q000472:pathogenicity / Q000528:radiation effects; D004203:Disinfection / Q000379:methods*; D006801:Humans; D010126:Ozone / Q000494:pharmacology*; D011549:Pseudomonas / Q000187:drug effects / Q000472:pathogenicity / Q000528:radiation effects; D014466:Ultraviolet Rays; D014865:Waste Disposal, Fluid / Q000379:methods*; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods*
chemical_list: D010126:Ozone