Skip to main content

Efficacy of “One Drop” Metal Ion Disinfectant for Inactivation of Indicator and Pathogenic Microorganisms

Buy Article:

$17.50 plus tax (Refund Policy)

Or sign up for a free trial


The burden of unsafe drinking water falls most heavily on those without access to water infrastructure, including people in the developing world. Unsafe water containing harmful bacteria, viruses, and parasites kills more than 1.6 million people a year in the developing world, many of them children. The long-term solution to the problem of waterborne illnesses in developing countries is to provide universal access to safe, pathogen-free, and reliable piped water supplies; unfortunately, this solution is decades away in much of the developing world due to the high capital costs of water infrastructure construction and maintenance. Treatment of drinking water at the point of use (POU) has demonstrated health benefits for people who have access only to microbially contaminated drinking water sources. Chlorine is widely used for drinking water disinfection, and has been applied for POU treatment, but it is often rejected by users due to taste and odor problems and toxic disinfection by-products. Drawbacks of chlorine disinfection have led to a search for alternative chemical disinfectants for POU treatment of drinking water.

One such alternative is One Drop, an aqueous solution of natural ionic minerals, including silver, gold, aluminum and copper. These metal ions have been previously shown to have microbicidal properties when added to contaminated water. Metal-ion based disinfectants have the potential to be effective disinfectants when added in small quantities, without causing adverse human health effects or problems with undesirable taste and odor. In addition to inactivating microbes, One Drop may also interact with negatively charged microbes to facilitate settling or removal by filtration. In this work, One Drop was evaluated in the laboratory for its ability to reduce turbidity and indicator and pathogenic microorganisms in seeded test waters consisting of raw surface water. Reductions of E. coli B and coliphage MS-2 were measured in one-liter volumes of test water treated with 0, 1, 2, or 4 drops of disinfectant.

There were appreciable reductions of microbial indicators in One Drop treated water. Reductions of >6 log10 (>99.9999%) were observed for E. coli B and >5.5 log10 for MS-2. Reductions generally increased over time and with increasing disinfectant concentration. Microbial reductions in test waters treated with One Drop were more rapid and extensive than in test waters without the addition of One Drop. We conclude that One Drop reduces concentrations of some representative indicator and pathogenic microorganisms in raw water and may serve as an effective and low-cost alternative to chlorine for household or other point-of-use water treatment.

Keywords: disinfection; metals; point-of-use; water

Document Type: Research Article


Publication date: 2009-01-01

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access.
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free ContentFree content
  • Partial Free ContentPartial Free content
  • New ContentNew content
  • Open Access ContentOpen access content
  • Partial Open Access ContentPartial Open access content
  • Subscribed ContentSubscribed content
  • Partial Subscribed ContentPartial Subscribed content
  • Free Trial ContentFree trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more