title: Laboratory validation of an ozone device for recreational water treatment.
abstract: Obtaining an accurate assessment of a treatment system's antimicrobial efficacy in recreational water is difficult given the large scale and high flow rates of the water systems. A laboratory test system was designed to mimic the water conditions and potential microbial contaminants found in swimming pools. This system was utilized to evaluate the performance of an in situ ozone disinfection device against four microorganisms: Cryptosporidium parvum, bacteriophage MS2, Enterococcus faecium, and Pseudomonas aeruginosa. The sampling regimen evaluated the antimicrobial effectiveness in a single pass fashion, with samples being evaluated initially after exposure to the ozone unit, as well as at points downstream from the device. Based on the flow dynamics and log reductions, cycle threshold (Ct) values were calculated. The observed organism log reductions were as follows: >6.7 log for E. faecium and P. aeruginosa; >5.9 log for bacteriophage MS2; and between 2.7 and 4.1 log for C. parvum. The efficacy results indicate that the test system effectively functions as a secondary disinfection system as defined by the Centers for Disease Control and Prevention's Model Aquatic Health Code.
authors.affiliation: NSF International, Ann Arbor, MI 48105, USA. Donofrio@nsf.org
authors.forename: Robert S
authors.initials: RS
authors.lastname: Donofrio
authors.forename: Sal
authors.initials: S
authors.lastname: Aridi
authors.forename: Ratul
authors.initials: R
authors.lastname: Saha
authors.forename: Robin
authors.initials: R
authors.lastname: Bechanko
authors.forename: Kevin
authors.initials: K
authors.lastname: Schaefer
authors.forename: Lorelle L
authors.initials: LL
authors.lastname: Bestervelt
authors.forename: Beth
authors.initials: B
authors.lastname: Hamil
mesh_terms: D001431:Bacteriological Techniques; D001493:Bathing Beaches; D016785:Cryptosporidium parvum / Q000187:drug effects; D016984:Enterococcus faecium / Q000187:drug effects; D006801:Humans; D017909:Levivirus / Q000187:drug effects; D010126:Ozone / Q000737:chemistry*; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D011998:Recreation; D013551:Swimming Pools; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods*
chemical_list: D010126:Ozone