Author Topic: The Water Myth  (Read 8330 times)

captain paranoia

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Re: The Water Myth
« Reply #15 on: July 24, 2014, 06:23:43 PM »
krenaud,

DrinkSafe sell filters from a number of manufacturers (for instance, compare and contrast Seychelle with DrinkSafe's product range).  I'm sure they used to quote filter sizes, or filtration performance.

It's a while since I bought my filter from them, but I'm pretty sure it had an NSN and appropriate test figures.

They're usually very responsive to customer enquiries, so drop them an email and ask for figures and test results.
« Last Edit: July 28, 2014, 06:01:19 PM by captain paranoia »

Pete McK

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Re: The Water Myth
« Reply #16 on: July 25, 2014, 11:00:12 AM »
I have been considering buying some sort of system to purify water for our longer journeys, especially our planned trip to the Alps next month. Was the work you mention looking at different systems Lyle?

By the way, great article :) I have seen a lot more articles written by you in Trail and didn't know that you write for other magazines, can you load up these articles on the forum as well?

Sandy Sanderson

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Re: The Water Myth
« Reply #17 on: July 25, 2014, 11:10:16 AM »
I can remember reading about a water bottle that would produce clean drinkable water from fresh air.

At first i though that it was a joke article but after doing a little more research I found a small company in the U.S. called NBD NANO. They are currently in the process of biomimicking the Namib Desert Beatle which by produces it own water due to condensation in its outer shell.

Now if they actually manage to get this fully up and running then the applications of this, not just in the hiking community, would be extremely beneficial in warmer climates.

Here is a link to the company.

http://www.nbdnano.com/index.php

http://www.bbc.co.uk/news/technology-20465982

Will be good to see the water creation rate (if that’s the correct phrase) of one these bottles and the price.  As I would be very interested in purchasing one especially when working in the Middle East where drinkable water in more expensive than fuel.

Lyle Brotherton

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Re: The Water Myth
« Reply #18 on: July 26, 2014, 07:34:49 AM »
Thx Pete :) Yes I contribute every month to Trail Magazine, every issue of Mountain Rescue Magazine, two foreign language journals - they translate my work - and then occasional articles for other publications such as TGO and Wanderlust.

I have been 'meaning' to upload them for a while and following your prompt I will now do :)

Water purification: Yes Pete I have been part of a team looking at variously methods and different approaches to this with 3 primary objectives: safe drinking water, weigh/size and practicality. I must say that I have been surprised by just how little I actually understood ;) Summary soon to follow.

Sandy, fascinating product because the usual drawback with distillation, which is a brilliant method of purification even desalination water, is practicality and the time required to collect the water. I have pinged the manufacturer a series of questions which hopefully they will get back to me about and I will publish their answers in this thread.
« Last Edit: July 26, 2014, 07:39:26 AM by Lyle Brotherton »
“Opinion is the medium between knowledge and ignorance” - Plato

boogyman

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Re: The Water Myth
« Reply #19 on: July 27, 2014, 03:25:15 PM »
This topic (ie filtering water) gets more and more attention around the world. Here's another article describing "an innovative solution": Perforene gets patented.

Hugh Westacott

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Re: The Water Myth
« Reply #20 on: July 28, 2014, 07:06:34 AM »
I suspect that the amount of water required depends to some extent on  personal metabolism.

Last July I spent a week backpacking the South Cornwall Coast Path with my son during a heatwave when the temperature approached 30°C.

Austin is 147cm tall, is not overweight but sweats heavily and, on average, drank four litres of water between breakfast and dinner.

i am sixty years older than Austin and am 140cm tall, weigh 63.5kg and do not sweat much and, on average, drank one litre of water between breakfast and dinner. My urine remained a light straw colour throughout the day.

I grow old...I grow old, I shall wear the bottom of my trousers rolled. T.S. Eliiot

captain paranoia

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Re: The Water Myth
« Reply #21 on: July 28, 2014, 06:10:36 PM »
The Namib beetle bottle sounds interesting.  I am reminded of the Fremen stillsuits in Dune...

Sandy Sanderson

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Re: The Water Myth
« Reply #22 on: July 30, 2014, 06:56:04 PM »
Just been looking at replacing my Hydration system for my trip to lakes in September.

Lyle posted:

Quote
which is why only filtering stream water is risky as these portable filters do not remove viruses - they filter to 0.1 microns and to filter viruses out you need to go to 0.02 microns

And i found:

http://www.geigerrig.com/hydration-packs/accessories-Inline-virus-filter.html

The company states that it will remove removes:
 
≥99.9% Protozoans (Cryptosporidium and Giardia)
≥99.9999% Bacteria (Raoutella terrigena)
≥99.99% Virus (MS-2 Bacteriophage)

Not to sure about the top one, but i know the other 2 can be bad. The only thing that I cannot see on the website is filter size itself.

They also state:

This patent pending design and manufacturing method has been thoroughly tested and certified by independent laboratories to consistently remove protozoan cysts, bacteria, and virus to ANSI/NSF Standard 52, and US EPA standards without the use of disinfecting chemicals such as chlorine, bromine, or iodine.

I have tried to find the standards on the net but i just kept going round in circles on the EPA website.

I have also emailed the company requesting information on their inline filter, hopefully i will get a reply in the next few days.

Hoping this may kill 2 birds with one stone for me, a water purfication/filter system and hydration bag (Almost all in one).

boogyman

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Re: The Water Myth
« Reply #23 on: July 30, 2014, 08:23:16 PM »
Have you also looked at this water filter ?

Callum

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Re: The Water Myth
« Reply #24 on: July 30, 2014, 09:40:50 PM »
In a hyper-saturated (forgive the pun) outdoor consumer rehydration market, where businesses fight for attention, never mind sales, it should not be surprising that some companies stretch the boundaries for their products claims.

From the unsinkable Titanic, through the wonder anti-emetic Thalidomide to the performance sports drink Lucozade exaggerated product claims are something we should be aware of and, consequently, research before we purchase, especially when our well-being may well depend upon them.

captain paranoia

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Re: The Water Myth
« Reply #25 on: July 31, 2014, 06:47:10 PM »
I'm beginning to wonder if manufacturers have decided to stop quoting filter sizes, because there will be a manufacturing variation in pore sizes.  That's why a statistical specification may be more honest (% filtration), which probably correlates with the statistical variation of pore sizes in the manufacturing process.  One difficulty then comes in determining what percentage filtering is required to make the filtered water 'safe'; how many viruses does it take to make you ill?

The other obvious issue with all filtering systems is the separation of dirty side and clean side, and the difficulty of maintaining separation of the two.  It's easy to envisage ways in which dirty water could bypass the filter: drips running down the outside of the filter; a filter bottle being dunked in dirty water, and then this water dripping past the filter cap as water is drunk, etc.

Lyle Brotherton

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Re: The Water Myth
« Reply #26 on: August 02, 2014, 03:21:47 PM »
Boogyman used your link to view the Fitbottle from the USA.

On the homepage I was instantly suspicious with the claim “Removes up to 99.99997% of bacteria, viruses & harmful chemicals” because percentage contaminant removal values (the 99.99997% claimed) used are based on Log reduction values to show the relative number of particulates removed. Simply this is a way to express levels of decreased biological contamination in water by factors of 10 which are then easily converted to the corresponding percentage removal, where 1-log = 90% / 4-log = 99.99% / 6 log = 99.9999% and so forth, there would not be a 99.99997 at the end.

Reading on, they claim to remove metals such as mercury and nickel, volatile organic compounds such as formaldehyde, even viruses such as hepatitis and norwalk (winter vomiting virus) and all confirmed by “rigorously tested by a nationally certified laboratory” using “a patented filter media design” – this is a miracle product, achieving more than water utility companies, both in your country, Belgium and here in the UK, who are responsible for providing safe and clean drinking water who have to use a seven stage process of treatment to produce water to 6-log, not 7-log.

There is an old adage: If something seems too good to be true it probably is!

Despite several requests direct to the firm to provide me with the details of the national certified laboratory and their patent registration, in addition to an on-line search for such a patent – nothing :o

OK, this fir is at the extreme edge of making unsubstantiated and false claims about their filters to share in the US$15 Billion bottled water market, yet they are not alone; it’s a murky industry ;)

I had hoped to publish the results of my research sooner rather than later, however I have to await approval from the rest of the group before I release any finding and it may well be some week, possibly months yet.
“Opinion is the medium between knowledge and ignorance” - Plato

captain paranoia

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Re: The Water Myth
« Reply #27 on: August 03, 2014, 10:42:08 PM »
Whilst I'm always wary of spurious claims, I'll make a couple of comments here.

A percentage is just that; a fraction expressed in terms of in 100.  A filter may remove 99.99997% of contaminants, and this figure isn't necessarily derived from a simple integer log rating; things do not work in simple factors of ten steps.  Specifications may use a log rating, but the chances are very, very high that their actual performance will fall somewhere between the log values.  Actually, its performance can be expressed as a log value, but that value will not be an integer.  99.99997%, for instance, is a −6.5228787 log filter (that's log10(1-0.9999997) ).

The issue of the performance of a portable filter vs an industrial scale water treatment plant might well be explained by the issue of throughput; a portable filter doesn't need to have a flow rate anything like a municipal treatment plant, so, potentially, can have a superior filtration performance.
« Last Edit: August 04, 2014, 06:19:30 PM by captain paranoia »

captain paranoia

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Re: The Water Myth
« Reply #28 on: August 04, 2014, 06:39:02 PM »
The other issue with industrial water treatment is that, as Lyle says, a number of processes are used, with biological digesters*, sand filter beds, etc.  One of the last stages (as I understand it) is the use of a flocculant to encourage the very small particles to cluster together, allowing a larger filter to be used.  A common flocculant is aluminium sulphate, and it was an error in the dispensing of this which caused the Camelford incident (the delivery driver dumped the tanker load into a water output tank, rather than the aluminium sulphate storage tank, leading to a massive overdose of the flocculant).

Then there is the fact that water sources come from controlled locations (reservoirs) and the use of chlorination to kill biological contaminants.

Thames Water have a rather 'picture-book' explanation of water treatment.

* actually, these are used for sewage treatment.

Oakleaf

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Re: The Water Myth
« Reply #29 on: August 08, 2014, 07:50:24 AM »
With apologies for drifting the topic back to snakes -

http://www.theguardian.com/environment/2014/aug/07/man-bitten-three-times-adder