[pct-l] Aquamira - at 1/15th the cost?

[Hikers Two]

There is no question that chlorite (which AM employs) is best for on-trail oxygen disinfection of water. From info available, point-of-use mixing gives best results, "best" being 'predictably effective', or maybe, 'death by parasites avoided'. Since this is dealing with your health, wouldn't it be most prudent to follow the AM destructions for mixing and use? Pre-mixed chlorite solutions are available but (from info available), chlorite concentration (efficacy) at time of use (when you dispense into the nasty water you're about to chug) can vary according to solution age, heat, light exposure, etc.

Not to hijack the thread, but if any chemists, why not take on the bigger question of homemade AM at much lower cost? AM's price is $15/oz, parts A and B. The 'A' is sodium chlorite at 2% concentration; 'B' is phosphoric acid at 5%. But one can freely purchase 4 oz of 28% sodium chlorite (~22% chlorite(?) for a mere $20, enough to make ~46oz (by my calculation). That's under $1/oz for Part A, including shipping and the DI water for dilution. Phosphoric acid (part B) is abundant in the food supply, but more difficult to purchase in consumer quantities. Citric acid, which is readily available and very inexpensive, is commonly used as the reactant to produce chlorite for human consumption.

So with proper handling and storage (of course "use" also, which would be the same as for AM), the question is whether hikers can get the same results as with AM, but at a much lower cost. (AM operatives, provide predictable scary reply here.  :^)



Notes And Concerns

1. The chlorite part that does the work is also called 'chlorine dioxide'. Even though chlorine is present, it apparently doesn't take part in the reactions that kill the pathogens. (The AM narrative says "contains no *active* chlorine," asterisks added.)

2. AM's part A is "stabilized," probably referring to the low concentration (2%) and small amounts of added sodium hydroxide. The 28% solution probably also contains this stabilizer, or perhaps some other. Having a fully potent solution is essential.

3. One chem lab manager mentioned that added buffering agents may be present in AM's solution. The reference material says that as long as the pH is kept below the threshold value, chlorite will be produced as the reaction goes on. (In other words, just be sure there's an abundance of acid (implying no buffering agents needed) and all will go right.)

4. Probably most of that $15/oz AM price is buying confidence. The homemade version may work just as well today, but without a qualified chemist(s) to say so, widespread use is doubtful.


Free enterprise in a lawful society is wonderful. When a product is way overpriced, in this case $15 vs $1 /oz, there's an opportunity for alternatives.

Bill



  From: jason moores 
  Sent: Thursday, March 05, 2009 5:15 AM
  To: pct-l at backcountry.net 
  Subject: [pct-l] Aquamira



  My understanding of how Aquamira(chlorine dioxide) works is basic and based on only a small amount of research, but here I go...I combine appropriate amounts of bottle A. Stabilized Chlorine Dioxide with bottle B. Phosphoric Acid. Let sit for 5 min. to allow for the chemical reaction, which releases oxygen molecules. It's these molecules that "oxidize" (read: kill) the pathogens in the water. 

  How long do I have before this chemical reaction reaches an end, or becomes inert? If I can mix up some solution prior to reaching my next water source it will shorten the time until we'll be able to drink our treated water. 

  I normally carry my drops in my hip belt pocket. On longer water stretches I utilize a second mixing cap kept from a previous set. This is enough mixing space for a couple of gallons of treated water. I'll be treating water for two people so I'm adding a tiny 1oz squeeze bottle to my pouch for the additional mixing space I'll need for water in the desert. (maybe as much as 16 liters at some stops) I figure I'll mix my solution as I skip down the path and be ready to go when I get to the next source. 

  Does anyone know how long this reaction lasts? Is there some flexibility here or do I need to add this mixture soon after the 5 min. mark? 5 min. is a small amount of time to wait (plus the 15 min. wait after adding Aquamira) and I'm really not sweating that. The more I thought about it the more curious I became. I checked a few sites but found nothing about shelf life after mixing. Any chemists out there?

  jason

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