2015-07-12

water purification

web.aq.care/water purification:
7.11: summary:
. we should store water for emergencies;
boiling is the simplest way to purify water;
but to store tap water in sealed containers,
you can keep it fresh with chlorine dioxide,
(not to be confused with chlorine bleach).
. if there's a chance the water has
protozoa protected by the dormant cyst form
such as Giardia and Cryptosporidium,
only boiling or a submicron filter can remove them
but you don't usually find them in tap water .

14.2.9: 15.7.11: web.aq.care/amazon/water purification:
Chlorine dioxide vs halogens:
Halogens (chlorine bleach, iodine) are persistent;
they are slow to degrade and are germ killers
long after being added to water;
chlorine dioxide mixtures are not persistent:
they sterilize water and then break down,
so if your water isn't sealed,
then the germs that come later
can thrive in the water [CDC]

iodine purification raises TSH:
Tetraglycine hydroperiodide tablets purify water
by liberating 8 mg free iodine per tablet.
Serum TSH and the TSH response to TRH
rose significantly after 7 days and remained elevated
for the full 3 months of the study.
The average thyroid volume increased by 37%.
Neither hyperthyroidism nor hypothyroidism was observed
[J Clin Endocrinol Metab. 1995].
. very elevated TSH may cause the thyroid gland
to become enlarged (compensatory goiter) [endocrineweb];
and high intake of iodine may increase the risk of
autoimmune thyroiditis [j Am Dietitic Assoc 1990];
but high iodine may offer health benefits
[J Amer Physicians and Surgeons 2006]
including cancer prevention.
. see Iosol 8oz, and 1oz with dropper.

. boiling is one of the few water treatments
that can remove all pathogens, including cysts;
Water should be brought to a rolling boil for 1 minute.
At altitudes greater than 6,562 feet
you should boil water for 3 minutes.
. for Giardia and Cryptosporidium
chlorine dioxide has a low to moderate effectiveness;
whereas Filtration has a high effectiveness
when using an absolute less than or equal to 1 micron filter
(NSF Standard 53 or 58 rated "cyst reduction / removal" filter).
. chlorine dioxide has a high effectiveness in
killing bacteria and viruses;
whereas filters are not stopping all viruses [CDC].

Filters with the EPA designation of water purifier
undergo company-sponsored testing that has demonstrated
removal of 10^6 bacteria, 10^4 (9,999 of 10,000) viruses,
and 10^3 Cryptosporidium oocysts or Giardia cysts.
(EPA does not independently verify these claims) [CDC].

different ways to get chlorine dioxide:
. Potable Aqua's chlorine dioxide
comes as 6.4% sodium chlorite mixed with
1.0% sodium dichloroisocyanurate dihydrate.
. AquaMira chlorine dioxide consists of
a 2% sodium chlorite solution
mixed with a 5% phosphoric acid solution.

Micropur mp1 [Katadyn; Micropur purification]
The EPA Registered Name for this product is:
Aseptrol-SE water purifier tablets:
6.4% sodium chlorite
1.0% sodium dichloroisocyanurate dihydrate.

re: sodium dichloroisocyanurate dihydrate;
beware water tainted with melamine:
. some chlorine dioxide products contain
sodium dichloroisocyanurate dihydrate
which releases cyanuric acid in water;
this seems to be the catalyst to make
chlorine dioxide from sodium chlorite .
. but if your water is contaminated with melamine,
cyanuric acid forms melamine cyanurate
which harms kidney.
Pet food containing both melamine and cyanuric acid
has caused kidney failure in cats and dogs
[USA; 2007].

. the authors of that warning recommend
MMS (Master Mineral Solution:
Sodium chlorite and citric acid).
. mixing sodium chlorite solution with a
food-grade acid (commonly citric acid),
results in 5–35% chlorous acid
with 65–95% chlorite
(more acidic solutions result in
a higher proportion of chlorous acid).
Chlorous acid breaks down to chlorine dioxide
which in turn breaks down to chlorite anion [ClO2−]
and ultimately chloride anion [wiki].

. waterborne bacteria have the ability to live
either as a free-floating planktonic form,
or as a community in a biofilm.
. the biofilm has an extra cellular matrix
which resists penetration of chemicals,
and makes a biofilm more difficult to kill.
Filtration devices often clog due to biofilms.
Aquamira results predominantly in hypochlorous acid [HClO]
which is considered to be
a better biofilm disinfecting agent
than either Cl2 [chlorine gas] or OCl-[hypochlorite]
because of its ability to penetrate the biofilm matrix.
Aquamira worked better than iodine on biofilms
[Backpacking Light SPRING 2005].

AquaMira mixing in large batches:
"The chemicals released so much heat
that the container was almost too hot to touch;
The mixture also releases a noxious smelling light smoke,
so use it outside."

$20 LifeStraw Personal Water Filter:
#1 Best Seller in Camping & Hiking Water Filters
troubleshooting:
"Upon testing of returned units,
we've found that in most cases
What you need to do is uncap it
and stand it up in a glass of water for 30 seconds;
This allows the water to creep up the membrane.
Then take five quick sucks and the water should flow fine.
Blow back into it to clear any debris from the membrane.
If this still does not work,
please take advantage of the generous return policy."

$20 Sawyer Products Mini Water Filtration System:
review by AC:
" if your filter clogs 4 days into a 10 day backpacking trip
it may be useless unless you have house water pressure
as suggested by the company.
I won't stop carrying purification tablets
and something to boil water in.
I would still buy it,
yes you can get the job done with it
and it still appears to be the best water filtration
in my 40-plus years of backpacking experience."

Micropur MT 5 is 0.25 % silver:
. it has a bacteriostatic action,
causing at least loss of germ reproduction
if not death of germs.
silver ingestion can turn you blue .