Inactivation of Legionella pneumophila by copper-silver ions and free chlorine
AuthorLandeen, Lee Kevin, 1965-
Microorganisms -- Effect of metals on.
Chlorine and derivatives as disinfectants.
Water -- Purification.
AdvisorGerba, Charles P.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractWater disinfection systems utilizing electrolytically generated copper:silver ions (200:20 to 400:40 ug/L) and low levels of free chlorine (0.1 to 0.4 mg/L) were evaluated at room (21-23°C) and elevated (39-40°C) temperatures in filtered well water (pH 7.3) for their efficacy in inactivating Legionella pneumophila (ATCC 33155). A contact time of 24 hr was necessary for copper:silver (400:40 ug/L) to achieve a 3 log₁₀ reduction in bacterial numbers at room temperature. As the copper:silver concentration increased to 800:80 ug/L (K = 7.50 x 10⁻³ log₁₀ reduction/min), the inactivation rate significantly (p ≤ 0.05) increased. In water systems at room temperature with and without copper:silver (400:40 ug/L), the inactivation rates significantly increased as the free chlorine concentration increased from 0.1 mg/L (K = 0.397 log₁₀ reduction/min) to 0.4 mg/L (K = 1.047 log₁₀ reduction/min). All disinfection systems, regardless of temperature or free chlorine concentration, showed increased inactivation rates when 400:40 ug/L copper:silver was added; however, this trend was significant only at 0.4 mg/L free chlorine.
Degree ProgramGraduate College
Microbillgy and Immunology