Efficacy of a combined system of copper and silver and free chlorine for inactivation of Naegleria fowleri amoebas in water

J. M. Cassells, M. T. Yahya, Charles P Gerba, J. B. Rose

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

Electrolytically generated copper and silver ions (400:40 and 800:80 μg/l) were evaluated separately and combined with 1.0 mg/l free chlorine, for their efficacy in reducing the viable numbers of Naegleria fowleri amoebas in water (pH 7.3 and 23-250C). Inactivation rates (k = log10 reduction/min) and T99 values (exposure time required to achieve a 99% or a 2 log10 reduction) of the disinfectants were determined. Copper and silver alone, at ratio of 400:40 to 800:80 μg/l caused no significant inactivation of N. fowleri even after 72 hours of exposure (k = 0.00017 and 0.00013, respectively). Addition of 1.0 mg/l free chlorine to water which contained 400:40 or 800:80 μg/l copper and silver resulted in enhanced inactivation rates (k = 0.458 and 0.515, respectively) compared to either chlorine alone (k = 0.33) or the metals alone. Water containing 800:80 μg/l copper and silver with 1.0 mg/l chlorine showed a T99 value of 3.9 minutes, while chlorine alone showed a T99 of 6.1 minutes. Enhanced inactivation of N. fowleri by a combined system of free chlorine and copper and silver may be attributed to the different mechanism that each disinfectant utilizes in inactivating the amoebas, and may suggest a synergistic effect.

Original languageEnglish (US)
Pages (from-to)119-122
Number of pages4
JournalWater Science and Technology
Volume31
Issue number5-6
DOIs
StatePublished - 1995

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Chlorine
chlorine
silver
Silver
copper
Copper
Disinfectants
Water
water
ion
metal
Ions
Metals
disinfectant
exposure
rate

Keywords

  • Amoebas
  • Chlorine
  • Copper
  • Disinfection
  • Inactivation
  • Naegleria fowleri
  • Silver

ASJC Scopus subject areas

  • Water Science and Technology

Cite this

Efficacy of a combined system of copper and silver and free chlorine for inactivation of Naegleria fowleri amoebas in water. / Cassells, J. M.; Yahya, M. T.; Gerba, Charles P; Rose, J. B.

In: Water Science and Technology, Vol. 31, No. 5-6, 1995, p. 119-122.

Research output: Contribution to journalArticle

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