Water disinfection methods

Posted by: chaosmagnet

Water disinfection methods - 08/21/13 03:25 AM

Updates to the list in this color.

Costco had a Steripen for a nice price so I picked one up. It led me to think about disinfection methods.

  • Iodine tabs, like Potable Aqua. They make water taste nasty unless you have the neutralizer or drink mix to put in it, and reportedly don't work against Giardia
  • Chlorine dioxide tabs, also like Potable Aqua. I think they're a bit easier to use, they don't make water taste nasty, and they work against Giardia.
  • Calcium hypochlorite, such as pool shock. Best used when treating a large volume of water, I would think. Requires more steps than the other methods, but can also be used to create a bleach disinfection solution for other purposes.
  • Boiling. If you have a container, fuel and a way to make fire, can't be beat.
  • SODIS. Easy if you have the container, sunlight and time.
  • Steripen. Quick and easy...if you have batteries.
  • Filters. Quick and relatively easy, but may not remove viruses.
  • Iodine crystals. Roughly the same as iodine tabs? Need more information.
  • Miox. Uses both batteries and salt, not sure if there's an advantage to this.
  • Bio-sand filter. A great option for long-term use in a single location, not very portable.
  • Household bleach. Like the calcium hypochlorite but easier to use and doesn't store as long.





My field experience is limited -- I've boiled water while camping but normally I bring water so as not to have to treat it. Have I missed any methods that I should consider? What have been your experiences?
Posted by: hikermor

Re: Water disinfection methods - 08/21/13 03:57 AM


Boiling is definitely my preferred method. It has always worked for me, in some cases with some pretty nasty water sources. I am not so sure that water literally has to reach the boiling point to kill bugs; after all, milk is pasteurized by heating to 165F which is the same temperature to which safely cooked meat should reach. Years ago, I routinely drank untreated water from mountain springs, but I am a bit more cautious now.
Posted by: bacpacjac

Re: Water disinfection methods - 08/21/13 04:05 AM

Boiling is my favourite method too. I do carry a few MicroPUR tabs and a filter straw in most of my kit set-ups though, unless there's snow on the ground or I know I'm going to be able to access water. Especially during our short summer, it's nice to be able to drink water without having to wait for it to cool down after boiling. (They're also an easier way to make potable water when I'm dealing with the kids.)
Posted by: leemann

Re: Water disinfection methods - 08/21/13 04:15 AM

Resublimed Iodine Crystals (polar pure) is another method.
Posted by: AndrewC

Re: Water disinfection methods - 08/21/13 04:19 AM

Love my water filter - fine enough filter to remove Giardia. I never really use anything else. Doesn't have any chemical taste or leave the water tasting flat like boiling does, and doesn't take anywhere near as long as chemicals or boiling either. Water tastes delicious filtered out of a mountain stream!
Posted by: Burncycle

Re: Water disinfection methods - 08/21/13 09:49 AM

Primarily I prefer to boil but my go to emergency method when that is not an option is chlorine dioxide tablets. It will kill viral, bacterial and cyst based threats. I do have a water filter straw but that alone won't eliminate all threats (viruses are too small and will get through). Its primary advantage is allowing me to drink water treated with chlorine dioxide in 15-20 min (after bacteria ane viruses have been killed) instead of having to wait 4 hours for it to kill the cysts too, and for taste. Which is why I don't invest in the super expensive pump type filters. Hell a Millbank bag would work if you are just trying to keep the chunks out.

It seems to me steripen is a decent setup but it doesnt fill a niche for me at the moment. I would imagine because it depends on exposure to UV light that water would have to be pretty clear for it to be effective and might need to be used in conjunction with basoc filtration (even handkerchief) for best results.

Miox makes a water purification setup that uses batteries and salt to make an ionized solution that is supposed to work well and IIRC you can tweak it to purify different amounts..
Posted by: LesSnyder

Re: Water disinfection methods - 08/21/13 01:23 PM

I don't spend time in the outdoors like most of you do, but I do carry a half dozen chlorine dioxide tabs and a water transport bag in my wallet... my major concern is "boil order" for water main burst or contamination with a sewer line... so I opted for the .1 micron Sawyer 5 gal bucket for home... backed up with calcium hypochlorite/Clorox... just a lot more convenient for an old guy
Posted by: JPickett

Re: Water disinfection methods - 08/21/13 03:17 PM

I would not clain expertise in this subject, but my understanding is filters will remove larger nasties such as bacteria, amoebas and cysts; but will let viruses pass through. If your in a region where the viral load of streams is high, you need more than a filter. Either a purifier or chemical treatment is indicated. If the viral load is low, a filter is sufficient.
Mechanical filters and purifiers both have the problem of clogging, but prefilters help.
When i have camped, I have usually been happy with a filter.
Posted by: JerryFountain

Re: Water disinfection methods - 08/21/13 04:08 PM

Chaosmagnet,

I have the lot of tools for water prep (Steripen, Miox, Katadyn Filter, Tea Kettle, tabs, etc.) and they are all great in certain circumstances. For most uses though the new Sawyer Purifyer filters which will remove virus will do it all. I will still use the others where their strengths fit, but the Sawyer will do most of them almost as well and in many cases better.

Since virus populations are low in most of the North American Wilderness, a filter (I have used a Katadyn Pocket for over 30 years) has been my go to for normal use. Before that, in the high rockies I did not use anything. It also has worked well when traveling, but newer tools have displaced it there.

The Steripen is now my normal traveling (out of the country) source, Works well in a hotel room or by a lake or stream. Kills everything but works best in clearish water. Also great for canoeing. Biggest limitation is the amount of water you can produce at one time. Not good for group camping or in the desert where you may have to fill several gallons at one time. In the canoe you can quickly produce a bottle full any time you need it. Often used with Miox (or now the Sawyer) for working from canoes or small boats.

Miox (produces chlorine dioxide) is great for producing large quantities of water at one time but is slow for anything (15 min to several hours depending on potential problems). It is slowest for large cysts which are common in North American Waters. In third world countries I have been known to filter then use Miox for virus (the shorter time frames. This is a common recommendation from the Wilderness Medical Society (to use two methods). When working from a base camp in canoes, I set up a bag or two(10L) at the camp, fill it in the morning and have safe water when I return for dinner and cleanup. After dinner I fill the bags again and have water for the morning. I use the Steripen during the day since water is all around. The Sawyer bag to bag purifier may replace this, but not necessarily.

Tabs I have used in the past, still use after filtration in places where virus are a problem and I carry them in emergency kits because they are small. Taste and quantity of water are problems so although I usually carry some, I don't actually use them much any more.

The Sawyer I have is a gravity filter and requires 2 bags, dirty and clean. It works best as a replacement for the Miox and MSR bladders. It needs to set for a while.

I understand Sawyer is going to bring out a portable version of there filter (it may be out) which will be great for other uses as well. Just look carefully, some Sawyers are filters and some are Purfyiers.

Respectfully,

Jerry
Posted by: clearwater

Re: Water disinfection methods - 08/21/13 05:41 PM

Bio-Sand Filter-Long Term, Household

http://www.cawst.org/en/resources/biosand-filter

"The biosand filter has been studied in the field and in labs. It has been shown to remove the following from contaminated water:

Up to 100% of helminths (worms)
Up to 100% of protozoa
Up to 98.5% of bacteria
70-99% of viruses
The filter can also remove up to 95% of turbidity (dirt and cloudiness), and up to 95% or iron (which people often don’t like because it turns water, laundry and food red!). Like other filters, the biosand filter cannot remove dissolved contaminants or chemicals, such as salt, arsenic or fluoride. There is an adaptation of the biosand filter using rusty nails, called the Kanchan Filter, which can remove arsenic from water."
Posted by: Pete

Re: Water disinfection methods - 08/22/13 03:10 AM

after a million different approaches here and overseas I prefer two methods ... (1) buy good bottled water, or (2) BOIL IT. both are simple and the water tastes good afterwards.

cheers,
Pete2
Posted by: MDinana

Re: Water disinfection methods - 08/22/13 02:53 PM

I'm a filter fan. Worked fine for 10+ years of camping in CA as a boy scout.

Problem with the other methods is filtering the particulate matter.
Posted by: Am_Fear_Liath_Mor

Re: Water disinfection methods - 08/22/13 03:44 PM


Using a Millbank bag and a Ghillie Adventurer is useful for long term field use. Sterilised water will probably used for making tea/coffee and freeze dried food anyway.

Filters such as Ceramic filters produced by Katadyn are also very useful as well. I keep a Katadyn Syphon filter inside a Ortlieb 10 litre water storage bag with shower attachment next to an S10 respirator and a Geiger Counter in a PLCE respirator bag.

http://www.amazon.com/Katadyn-1120070-Siphon-Filter/dp/B0007U0102
Posted by: Burncycle

Re: Water disinfection methods - 08/23/13 03:15 AM

Originally Posted By: chaosmagnet

[*][color:#009900]Filters. Quick and relatively easy, but may not remove cysts.



I think you mean may not remove viruses. Filters take care of cysts pretty well due to their larger size.
Posted by: Arney

Re: Water disinfection methods - 08/23/13 06:22 PM

Let's not forget good old household liquid bleach (non-scented, non-"Ultra" type). In a disaster situation at home, next to boiling, using bleach is probably going to be the most commonly available form of water purification for the vast majority of households, even for folks without any special preps.
Posted by: chaosmagnet

Re: Water disinfection methods - 08/23/13 09:08 PM

Originally Posted By: Burncycle
I think you mean may not remove viruses. Filters take care of cysts pretty well due to their larger size.


Thanks for the correction; I'll fix the list.
Posted by: chaosmagnet

Re: Water disinfection methods - 08/23/13 09:10 PM

My plan is to write a better summary for each method based on the input in this thread. I think I've got a reasonably good handle on this other than the Miox.
Posted by: haertig

Re: Water disinfection methods - 08/23/13 09:53 PM

I used to just use iodine tablets back in the 70's. We would add powdered Jello to the water to make it taste better, not that I thought it was horrible plain. It wasn't great, but not horrible.

Iodine tablets are a major fail when you cook your noodle dinner in iodine water though. Unless you like purple noodles.
Posted by: wileycoyote

Re: Water disinfection methods - 08/25/13 05:20 PM

while my first line is a katadyn pocket pump, my back-up is a $2 mini squeeze bottle of TINCTURE OF IODINE 2% (5 drops/qt on warm clear water then wait 30 minutes, or 10 drop/qt if water is cold or dirty, wait one hour). bad taste in water can be removed by adding vitamin C pills/powder after water is ready to use.

available at any Rx or big-box store...
Posted by: JerryFountain

Re: Water disinfection methods - 08/25/13 07:27 PM

Chaosmagnet,

The Miox is another chemical system, basically a different form of tablet. You make a fresh solution of mixed antioxidants for each run. The salt is converted by electrolysis into a suite of antioxidants, including chlorine dioxide. The big advantage of this is that there is no expiration date. You may also make as much or as little as you need (within the design of the system). It is much larger and heavier if you don't expect to use it much, much lighter and less expensive if you are going to make lots. It is certified to kill everything, but, like tablets, you have to wait. Hours if you have to kill cysts - one of the most common problems in North America, and world wide. An excellent system if you are at a base or using a vehicle and can have multiple containers. Good if you are prefiltering and only need to kill virus (only a 15 min. wait). Not bad if you can wait. Not so good IMO if you are hiking and wish to limit the number of containers you carry.

Respectfully,

Jerry
Posted by: Pete

Re: Water disinfection methods - 08/26/13 12:34 AM

within the USA I have used the filters extensively and they work fine.

overseas, the ENEMY of all "systems" is good old-fashioned dirt. once you've got dirty water as your starting ingredient, all bets are off. filters clog fast and are a real hassle to clean (especially Katadyn's).

chemicals like bleach, iodine, chlorine all taste pretty bad in the water. nothing cancels out the taste. most people will not drink it once it tastes terrible, so the majority of people get dehydrated. have to admit that I was the most disciplined of the people in the various groups that I traveled with, and even I got sick of "chemical water" fairly quickly.

strain out the large gunk, and boil the water.
or buy pure.

cheers,
Pete
Posted by: UTAlumnus

Re: Water disinfection methods - 08/26/13 01:20 AM

IIRC pouring between containers will help with chlorine taste. If time isn't a factor, letting it stand for a day will also remove the chlorine content if it is regular chlorine and not a chloramine.
Posted by: JPickett

Re: Water disinfection methods - 09/16/13 03:51 PM

While perusing the 'net, I came across the Seychelle water filter, something I remember reading about; not always in a good light. Anyone here have an opinion on this product?
Posted by: acropolis5

Re: Water disinfection methods - 09/16/13 05:11 PM

JPickett, based upon my own Internet research, I've chosen the Seychelles Advanced Water Purifer bottles and straws as my first line PSK and GHB water treatment. I did not find any negative comments on their efficacy. If you have a source or sources of negative commentary, please share. Usual disclaimer, I have no affiliation with Seychelles . I'm just a purchaser.
Posted by: Nomad

Re: Water disinfection methods - 09/17/13 01:49 AM

I think the Sawyers filters have revolutionized the purification process. After a lot of research, my daughter in Brazil is using one as her primary water source. They make two versions. One that does not filter virus as that is not much of a problem in most countries, and one that does filter virus.

I don't have the information in front of me so for details check out

http://www.sawyer.com/tech-water.html

I have several of each and find them very easy to clean (backflush) and both have good flow rates considering what they are doing.

The original .1 squeeze filter, which uses a plastic bag which is squeezed to force water through the filter had a bad reputation for leaks. However in my opinion people were playing gorilla with it. At about 3 oz, it makes a very good survival item.

Two versions of .1 micron are for sale at Walmart for about $30. One is a bottle, the other the squeeze.

Nomad.
Posted by: LesSnyder

Re: Water disinfection methods - 09/17/13 03:14 AM

pic of a Sawyer .1micron kit for a 5gal bucket... a kit is even available with the spade bit to drill the hole in the bucket, and comes with a syringe to back flush...I stick some tape over the hole, and place the kit in the bucket with a lid... good peace of mind for the central Gulf coast....