Inactivation of fecal bacteria in drinking water by solar heating.
We report simulations of the thermal effect of strong equatorial sunshine on water samples contaminated with high populations of fecal coliforms. Water samples, heavily contaminated with a wild-type strain of Escherichia coli (starting population = 20 x 10(5) CFU/ml), are heated to those temperatures recorded for 2-liter samples stored in transparent plastic bottles and exposed to full Kenyan sunshine (maximum water temperature, 55 degrees C). The samples are completely disinfected within 7 h, and no viable E. coli organisms are detected at either the end of the experiment or a further 12 h later, showing that no bacterial recovery has occurred. The feasibility of employing solar disinfection for highly turbid, fecally contaminated water is discussed.
Joyce
T M
TM
Department of International Health and Tropical Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland.
McGuigan
K G
KG
Elmore-Meegan
M
M
Conroy
R M
RM
D003889:Desert Climate; D003906:Developing Countries; D004203:Disinfection / Q000379:methods*; D004926:Escherichia coli / Q000302:isolation & purification*; D005069:Evaluation Studies as Topic; D005243:Feces / Q000382:microbiology*; D006358:Hot Temperature; D006801:Humans; D066298:In Vitro Techniques; D007630:Kenya; D013472:Sunlight; D013997:Time Factors; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods; D014881:Water Supply