A Scout’s Campfire

Water Treatment Options - Part 2

November 20th, 2006 spryken

Continuing my series on Water Treatment, I want to look at chemical disinfection.

Chemical Disinfection generally falls into 2 categories….Iodine and Chlorine. It is not surprising since both elements belong to the same chemical family.

Iodine

Iodine can be used in tablet form (Potable Aqua, eg.), liquid (tincture of Iodine), or as a saturated Iodine solution (Polar Pure).

Tablets are convenient and easy to use. One tablet will treat 1 liter of water. However, the tablets loose their effectiveness with prolonged contact with air. The bottles should be tightly sealed and replaced every few months. Cost is about $.40 - $.50 per quart/liter of water.

Tincture of Iodine is difficult to use due to the imprecise measuring that is usually available on camping/backpacking trips.

Iodine Solution (Polar Pure) is easier to use. The crystals are stored in water, so the solution is always ready to use. Cost is about $.005/quart/liter.

Pros for Iodine are cost and ease of use. Iodine will eliminate bacteria and giardia cysts. It will neutralize viruses.

Cons - taste, although that can be hidden with drink powders, and I have heard that cryptosporidium is not affected. Another con is the time involved. To effectively treat all but viruses you need to treat the water for 1/2 hour, up to 4 hours for viruses.

Chlorine

Chlorine in the form of chlorine dioxide can be used to disinfect water. This is a typical treatment for municipal water systems. Chlorine dioxide can be used in tablet form (MicroPur eg.) or liquid (Aqua Mira).

MircoPur tablets treat 1 liter of water and cost about $.40 per liter.

Aqua Mira is a system that uses 2 liquids to generate chlorine dioxide. Cost is about $.12 per liter.

Pros for Chlorine Dioxide - cost and ease of use. Chlorine is effective against bacteria, viruses, giardia cysts and cryptosporidium.

Cons - taste, although it can be hidden with drink powders. Some people complain of a “lemony” flavor or swimming pool taste. Another con is the time involved. To effectively
treat all but viruses you need to treat the water for 1/2 hour, up to 4
hours for viruses.

For both chlorine and iodine, cold temperatures will affect treatment time. Prefiltering is needed for “dirty” water.

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