Iodine water purification tablets

Iodine is still commonly used in liquid and sofid forms for use in emergency preparation of drinking water sources. The solid forms are sold commercially by various vendors, and are widely distributed by the U.S. Army for use in austere environments. The U.S. Army iodine water purification tablets release 8 mg/1 iodine per tablet (Department of the Army, 2002). Current guidefines specify two tablets per 1-quart canteen of water with a minimum contact time of 35 min to disinfect and prevent giardiasis (Department of the Army, 2002). Among the species of iodine, elemental iodine (fy) and hypoiodous acid (HIO) are the forms with the greatest biocidal efficacy (White, 1999). At pH 8.0 and 25°C, the concentrations of fy and HIO are approximately equal (Snoeyink and Jenkins, 1980). 

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