ALN No. 57: Reed Table 1: Solar disinfection effectiveness by bottle type

Backing surface:	90% inactivation time (minutes):
	low sunlight* (<300 W m -2)	moderate sunlight* (300-700 W m -2 )	high sunlight (>700 W m -2)**
transmissive	153	89	58
absorptive	117	68	48
reflective	175	84	49
* mean values based on 7 experiments ** mean values based on 8 experiments Inactivation of a suspension of fecal bacteria (Escherichia coli ATCC11775) in water kept in sunlight within custom-made 1-liter solar disinfection bottles with either transmissive, reflective or absorptive backings as a function of average solar irradiance during the illumination period. Data are based on standard aerobic plate counts obtained on nutrient agar after 24 hours incubation at 37°C.