Sure there are plenty of water purification technologies and some like the solar still pictured here
sound pretty virtuous from an energy input standpoint. But the big stationary solution is of little value in an emergency, or for people who are traveling or dislocated. That's why it got our attention when the Procter & Gamble Company (NYSE: PG), USA, was awarded the 2005 Stockholm Industry Water Award in recognition of its development of the PUR -- Purifier of Water(R) drinking water treatment system
. Designed for use in the developing world,the product consists of an envelope of chemicals commonly used in conventional municipal water treatment. Each sachet contains powder to treat 10 litres of water and is effective in removing bacteria, viruses, parasites and some heavy metals in contaminated water.The powdered product, which includes ferric sulphate and calcium hypochlorite, is delivered in small envelopes costing US$ 0.10/each. The treatment process involves stirring the water for 5 minutes until clear, filtering the water through a cloth, disposing of separated floc, and, finally, letting the water stand for 20 minutes to allow for complete disinfection.
A wonder for disaster recovery and helping displaced people. Can hikers or "off-grid" folk make use of it? A dime for a couple gallons of clean water sure beats those $50 filters in the outdoor supply catalogs.
For reference: Established in 2000 by the Stockholm Water Foundation in collaboration with the Royal Swedish Academy of Engineering Sciences and the World Business Council for Sustainable Development, the award is presented each August during the annual World Water Week in Stockholm, August 21-27, 2005 ( http://www.worldwaterweek.org ).