Disinfection of Escherichia coli and Pseudomonas aeruginosa by copper in water.
When households lack access to continuous piped water, water storage in the home creates opportunities for contamination. Storage in copper vessels has been shown to reduce microbes, but inactivation kinetics of enteric bacteria in water by copper alone needs to be understood. This work characterized inactivation kinetics of Escherichia coli and Pseudomonas aeruginosa by dissolved ionic copper in water. Reductions of E. coli and P. aeruginosa increase with increasing dose. At 0.3 mg/L, there was a 2.5 log10 reduction of E. coli within 6 hours. At 1 and 3 mg/L, the detection limit was reached between 3 and 6 hours; maximum reduction measured was 8.5 log10. For P. aeruginosa, at 6 hours there was 1 log10 reduction at 0.3 mg/L, 3.0 log10 at 1 mg/L, and 3.6 log10 at 3 mg/L. There was no significant decline in copper concentration. Copper inactivates bacteria under controlled conditions at doses between 0.3 and 1 mg/L. E. coli was inactivated more rapidly than P. aeruginosa. Copper at 1 mg/L can achieve 99.9% inactivation of P. aeruginosa and 99.9999997% inactivation of E. coli over 6 hours, making it a candidate treatment for stored household water.
Water Missions International, 1150 Kinzer Street, Building 1605, N. Charleston, SC 29405-1484, USA.
Andrew M
AM
Armstrong
Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599, USA.
Mark D
MD
Sobsey
Division of Environmental Health, School of Public Health, Georgia State University, 140 Decatur St, Atlanta, GA 30302, USA E-mail: lcasanova@gsu.edu.
Lisa M
LM
Casanova
D003300:Copper / Q000494:pharmacology*; D004202:Disinfectants / Q000494:pharmacology; D004203:Disinfection / Q000379:methods*; D004926:Escherichia coli / Q000187:drug effects*; D007700:Kinetics; D050296:Microbial Viability; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods*
D004202:Disinfectants; D003300:Copper