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

摘要: Water disinfection systems utilizing electrolytically generated copper and silver ions (200 20, 400 40, or 800 80 micrograms/liter) low levels of free chlorine (0.1 to 0.4 mg/liter) were evaluated at room (21 23 degrees C) elevated (39 40 temperatures in filtered well water (pH 7.3) for their efficacy inactivating Legionella pneumophila (ATCC 33155). At temperature, a contact time least 24 h was necessary (400 achieve 3-log10 reduction bacterial numbers. As the concentration increased micrograms/liter, inactivation rate significantly (P less than equal 0.05) from K = 2.87 x 10(-3) 7.50 (log10 per minute). In with without micrograms/liter), rates as 0.1 mg/liter (K 0.397 log10 min) 1.047 min). Compared no significant differences observed when 0.2 mg liter micrograms tested 39 C. All systems, regardless temperature concentration, showed increase added; however, this trend only liter.