INACTIVATION OF FECAL BACTERIA IN DRINKING-WATER BY SOLAR HEATING

We report simulations of the thermal effect of strong equatorial sunsh ine on water samples contaminated with high populations of fecal colif orms, Water samples, heavily contaminated with a wild-type strain of E scherichia coli (starting population = 20 x 10(5) CFU/ml), are heated to those temperatures recorded for 2-liter samples stored in transpare nt plastic bottles and exposed to full Kenyan sunshine (maximum water temperature, 55 degrees C). The samples are completely disinfected wit hin 7 h, and no viable E. coli organisms are detected at either the en d of the experiment or a further 12 h later, showing that no bacterial recovery has occurred, The feasibility of employing solar disinfectio n for highly turbid, fecally contaminated water is discussed.