Efficacy of copper and silver ions and reduced levels of free chlorine in inactivation of Legionella pneumophila

Journal Article · Fri Dec 01 04:00:00 EST 1989 · Applied and Environmental Microbiology; (USA)

OSTI ID:5837939

Landeen, L K; Yahya, M T; Gerba, C P ^[1]

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1. Univ. of Arizona, Tucson (USA)

Water disinfection systems utilizing electrolytically generated copper and silver ions (200 and 20, 400 and 40, or 800 and 80 {mu}g/liter) and low levels of free chlorine (0.1 to 0.4 mg/liter) were evaluated at room (21 to 23{degree}C) and elevated (39 to 40{degree}C) temperatures in filtered well water (pH 7.3) for their efficacy in inactivating Legionella pneumophila (ATCC 33155). At room temperature, a contact time of at least 24 h was necessary for copper and silver (400 and 40 {mu}g/liter) to achieve a 3-log{sub 10} reduction in bacterial numbers. As the copper and silver concentration increased to 800 and 80 {mu}g/liter, the inactivation rate significantly increased. In water systems with and without copper and silver (400 and 40 {mu}g/liter), to inactivation rates significantly increased as the free chlorine concentration increased from 0.1 mg/liter to 0.4 mg/liter. Compared to room temperature, no significant differences were observed when 0.2 mg of free chlorine per liter with and without 400 and 40 {mu}g of copper and silver per liter was tested at 39 to 40{degree}C. All disinfection systems, regardless of temperature or free chlorine concentration, showed increased inactivation rates when 400 and 40 {mu}g of copper and silver per liter was added; however, this trend was significant only at 0.4 mg of free chlorine per liter.

• OSTI ID: 5837939
• Journal Information: Applied and Environmental Microbiology; (USA), Journal Name: Applied and Environmental Microbiology; (USA) Vol. 55:12; ISSN 0099-2240; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BACTERIA
CHLORINE
CHROMIUM
ELEMENTS
HALOGENS
INACTIVATION
LEGIONELLA PNEUMOPHILA
METALS
MICROORGANISMS
NONMETALS
SILVER
TOXICITY
TRANSITION ELEMENTS