Water Treatment

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Water Treatment

Post by heckdog » Thu Mar 27, 2008 10:19 am

What is the preferred UL method?

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Re: Water Treatment

Post by russb » Thu Mar 27, 2008 11:29 am

Preference is personal. All methods have pros and cons. If your preference is based solely on weight, then no treatment. I posted on another forum about different types and some of the pros/cons here is a copy of that post:

Your choice of water treatment should be based on what you are trying to remove/kill from the water supply.

For example: uV or chemical does not remove particulates such as heavy metals or salts. Filters do not kill or remove virii.

Different chemicals have differing abilities to kill microorganisms.

Household bleach (sodium hypochlorite) is very effective at killing virii (eg: rhinovirus, hepatitis, influenza, herpes, rubella ,HIV) and bacterium (staph, strep, salmonella, dysentery, e-coli) but not effective against cysts such as giardia and crypto.

Chlorine Dioxide (not to be confused with bleach) is effective at killing cysts such as giardia and crypto but requires much longer time (tests of 1/2 hour contact were ineffective at killing crypto).

Iodine does not kill crypto and may cause issues for those with thyroid problems. I do not remember if it is effective (or not) against giardia.

Iodine and chlorine are both halogens and use a similar process to attack the microorganisms. So it is no surprise that their limitations to cysts are so similar.

uV is often said to "not kill" microorganisms but instead render them sterile. If a cell is unable to reproduce it is considered dead. This is just semantics since the purpose of water treatment is to make water safe to drink. Whether one differentiates between dead and sterile is moot. uV limitations as mentioned earlier are the non removal of particulates. This can also be an issue if the water source in question is very turbid. The uV must be able to "hit" the cells. Dirty or cloudy water can inhibit the process.

In summary your water treatment decision should be based on what one is trying to kill/remove from the water and the source of the water. There are many who do not use any water treatment and instead are smart about their choices of source water. My guess is that even people who use water treatment will make efforts to get the cleanest water possible even before treatment and thus the "i have never gotten sick" is a result of safe water to begin with not a result of their chosen water treatment.

Now my disclaimer: I usually do not treat my water and instead rely on smart decisions on where/how to collect water. I carry a uV purifier when going into areas where I anticipate higher concentrations of human use (contamination IMHO is related most to human activity). In my emergency kit I carry a few tablets of chlorine dioxide, which if I use I allow treatment of hours to maximize safety.

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