I have found a great deal about water purification dealing with biological contaminants; not much on acquiring water from industrial or farm areas. This is highlighted more because of the disaster in Japan. Major disasters like Katrina and the earthquake in Japan pollute the water with much more than bacteria and viruses. In many parts of the world (and even our country) all ground water must be considered polluted.

How do you remove chemicals and heavy metals? Is it even worth trying? Are there any products which can do it efficiently? Will they fit in your BOB? Do they require power?

Carbon filter and cross your fingers.

Berkey filters are about the best you're gonna get. The travel size is pretty compact, but its stainless steel so weight might be a factor. Course you could always make your own using a black filter element and drilling a hole in a plastic bucket. Crude but effective.

How about Distilling? I know the process of Distilling,Rids the water of containing Minerals,for the purpose of Purification/Clarity/Taste,When making Whiskey,Shine,etc.Does Heavy Metal Contamination Mock the same Category as Mineral Contamination?

I would be pretty concerned about industrial contamination. I'm not sure any technique is guaranteed to remove the huge variety of junk that gets dumped down storm drains in industrial areas. I would consider that water source to be suspect.

A better approach might be to find clean water within the industrial district. There could be some in certain storage tanks, flushing reservoirs, water pipes, gutters on roofs etc. You might be better to scrounge around ... but look for pure water.

other Pete

Check out this thread: PURIFICATION OF WATER

In particular:

In a Disaster situation,such as What we are seeing Presently,I See No Shortage of Fuel!An Art Form pertains to Flavor of Finished Product,All I'm Seeking is Potable Water!

What about Pur packets?

Apparently its use flocculants can remove a lot of pollutants, how much exactly I'm not sure.

If I were in a situation where the only available water was highly contaminated with industrial or farm waste, an HTI filter would be my top choice. According to this FAQ it has shown 95% plus rejection of herbicides and pesticides and 85-90% plus rejection of heavy metals.

No affiliation with either of these and no firsthand experience.

I think you misunderstand the post. Different contaminants have different boiling points, many of which are lower than that of water (100*C/212*F).

In a closed system, many industrial pollutants will vaporize at lower temperatures than water, to be collected and condensed by the condensing coils and wind up deposited with your supposedly "purified" water in the collection container. So while you've eliminated those contaminants that have a HIGER boiling point than water, you still have those with a LOWER boiling point in your distilled water. And the majority of industrial solvents have a lower boiling point than water.

This could be accommodated by starting the distillation process with an open container to avoid collecting the more volatile contaminants until they have boiled-off, then sealing the system to complete your water purification cycle. The question that nobody seems to be able to answer is how long does this uncollected boil need to last for a given quantity of water to be effective. My guess is there's no fixed answer, it depends on what's present and in what quantities. If your collected water contains a large amount of a chemical with just slightly below 100*C boiling point, perhaps it would be impossible to effectively distill potable water.

Could boiling in an open container first, then condensing as described work? Maybe heating to below the boiling point for an extended period to remove the more volatile elements without losing too much water? A combination of filtering, heating, boiling and chemical treatment?

Understanding the process will enable you even if you do not have all of the right gadgets. Know more, carry less.

Although not very practical for producing large amounts of water or quickly, if portability and being able to operate without power are primary concerns, forward osmosis like HTI's product seems like a good choice for what you're describing.

Reverse Osmosis pumps will remove most of nitrates, phosphates and heavy metals from water. I would assume this will clog the filters of any hand held pump pretty quickly, but how quickly, I have no idea (and having no access to a lab I can't really tell for sure how effective they are).

The problems with ROPs are price, tiny volume of purified water (the manual life raft model produces about 1-2 litres per hour of manual pumping, the electricity run models are pretty decent but obviously, require a power source) and need for special replacement filters. On the plus side, they also desalinate sea water and remove most of the taste from any water.

For situations where you don't have access to such a pump. I would probably let water stand in a bucket until sediment falls to the bottom, scooping the top 2/3-3/4 and repeating the process two or three times. After that, add any normal water purifications and hope for the best.

-jh

Hope it rains and get your tarps and containers out.

If you're talking about your home area, contact your local Water Board and ask them what kinds of contaminants are in the local water (they know). Then ask what would be the best, least complicated way to deal with them in a major disaster situation.

Use the info now that is already available. Waiting until a problem erupts and then guessing on how to deal with it would seem to be the height of poor planning.

Sue

A bit further into the water purification thread linked:



Apparently it is not a time but rather a volume consideration. But don't take my word for it, I am by no means an expert. Blast on the other hand ...

Natural water sources were never really safe. What bears do in the woods, beaver fever (also known as giardia), naturally occurring alkali and arsenic, there are even some plants that can poison water in some rare situations. Point being that you can't assume the water is safe to start with.

Then you add humanity, leaking septic tanks, people squatting in the woods. Things get worse if those people are maintaining a golf course, grassy areas, growing crops with lavish applications of fungicides, herbicides, insecticides, fertilizers. But on top of this you can stack the abominable behaviors of country gear-heads dumping their used motor oil, agricultural and industrial dumping, general human carelessness and callousness.

But even that may be just the start. Consider the standing water in Haiti, or Japan after the tsunami. Mama was very careful with how and where she used that insecticide. She kept is sealed in its bottle well away from hard. Them the wave came along and ground her lovely and orderly home, and that bottle of insecticide, to splinters. The answer to the question; what is in the water is like the old James Dean line. When asked what he was rebelling against he answered back 'What you got?'. Pretty much every chemical, fuel, virtually anything that could get into the water is in there in some amount.

First way to get around this is to try to find cleaner water. Any rainfall, outside that falling through smoke from fires, or vapors from the nuke plant, should be collected. Outside that careful consideration of what is in the area is helpful.

After that some mix of skimming, settling and crude filtering would be a good start. After that carbon filters would be one way to go.

The other way is what Richlacal suggests.



Distillation would work well I think. I'm thinking of something like a Sierra stove. A stove that will allow you to convert the huge mounds of scrap wood into distilled water, hot food, warmth.

Forward osmosis systems could potentially remove chemical contaminants. See http://www.247water.org/. They advertise it as working on contaminated water.

Basically, they have a sugar/salt syrup on one side of a membrane. Dirty water goes on the other side. Osmotic pressure pushes H2O from the dirty side to the clean side.

Never used it myself but thought it might be worth having a couple of the emergency use versions in a kit.

Fuel and/or time intensive, not very mobile, and a number of contaminates evaporate as well and would condense in the system. Petrochems mostly, but IIRC there are some other ag chems that won't mind. You'll get out heavy metals and salts, so if you got the time, fuel, material and don't mind relatively low output, sure.

I believe the Seapack and Hydropack kits, the ones that use a syrup to promote osmosis, don't yield pure drinking water, but rather a sweetened drink, similar to sports drink. I recall reading something that sweetened drinks, including sports drink, aren't ideal for rehydration. Then again, gotta be better than nothing.

Maybe once things settle down in Japan there will be some new studies on the effectiveness of various filtering methods and devices to deal with these types of situations. Hopefully Consumer Reports or a similar objective organization will perform a scientific rather than empirical study.

Forward osmosis is an interesting concept, but I was not impressed by the amount of water they provided - something like half a liter per capsule, and that over a very long period. In any situation where you are doing even moderate work, that amount of water is minuscule. For most applications, it would be much simpler merely to pack the water in the first place.

I have had good experience with sports drinks for rehydration, although I usually dilute Gatorade about fifty-fifty with water. It is better that way when working hard.

A relevant excerpt from Zen Backpacking...............


http://zenbackpacking.net/WaterFilterPurifierTreatment.htm

The US military uses Chlor-Floc water purification tablets which uses aluminum sulfate as a flocculating agent.

Flocculating agents allow for removal of suspended solids in water by promoting rapid clomping and sedimentation of fine particles suspended in water. This sediment is then easily removed by straining the water through a cloth or by siphoning or pouring off just the clear water. This isn't a "filter" treatment in itself but allows for the removal many suspended solids to improve clarity and taste of water as well as decreasing the amount of treatment (chemical/filtration/heat/radiation/etc) needed for your water.

Flocculating and coagulation can remove 60–98% of microorganisms, heavy metals, and some chemicals and minerals from water.

And don't forget the simple, low-tech Slow Sand Filter, suitable for many homestead and survival situations: http://www.nesc.wvu.edu/ndwc/pdf/OT/TB/TB14_slowsand.pdf

If you're not looking for the most expensive, highest-tech, most-chemicals-required way to filter water, go with a method that is well over 100 years old, and is still used in some municipal facilities.

Some slow sand filters would look awfully good in many places in Japan right now...

Sue

Thank you for saying about the alum method - that's a really good way to start before the purification process and it's dirt cheap if you just pack some with you. It will bind to many of the nasty gunk in water, drag it down and you can separate it. Then from there do your normal distillation/boiling + filtering and that will give you about as good as you're going to get unless you have a reverse osmosis system to use in addition/aside from that.

Excellent article on it:
http://www.wikihow.com/Purify-Water

And that ladies and gents, is (IMHO) the best process we have available.

Susan ... thanks for posting the slow sand filter. Very practical. It won't remove everything, but could be very useful in a disaster situation. And it's pretty easy to construct. Maybe it would work even better if people mixed some charcoal with the sand - the charcoal might absorb some chemicals. Don't know if this would be an improvement. Just thinking out loud. Anyway, thanks for the link!

For water in urban sources, my own approach in L.A. will be to scavenge clean water from various locations such as water tanks, pipes, storage containers etc. I plan to work harder on developing this set of skills this year. I realized that I need a few items/tools
some garden hose
some sort of hand-powered pump
something that can drill a hole (or punch) through sheet metal

Pete #2

It is a nice rainy morning here in SoCal, a timely reminder that collection of rainwater/dew can be a viable source of good water, although that would not be the case in northern Japan right now....

For a charcoal filter, will any charcoal do? Is there a particular method to prepare it if you have to make your own? Charcoal is used in military chemical protective filters and suits, so I imagine it does work. How does it work, scientifically?

Montanero - I can help with part of the answer. No doubt the best thing to use for absorbing chemicals in water is proper charcoal (activated charcoal) available in stores. This charcoal is probably higher purity.

However, in primitive villages in the third world I know people who use charcoal (from campfires) for the same purpose. It is routinely used when they wash out gourds - which are used for storing liquids. Gourds can be used for water storage, but they are also used for storing milk and the preparation of "sour milk" (i.e. milk aged for 12 hours and deliberately soured before drinking). When the gourds are cleaned after the milk preparation, the people wash them out with a mixture of water and charcoal (from the firepit) to absorb impurities. Subsequently, any water from the gourd can taste a bit "ashy", but is essentially harmless for drinking. So my guess is that you could use charcoal from a campfire as a crude method for absorbing impurities in water.

Pete #2

Susan ... I was thinking a bit more about the sand filter. A couple of things came to mind. The first is that you would need to have clean sand. If the sand has any salt or soluble minerals, they will get into the water. This is probably why the folks in Japan are not using this method in the tsunami zones. All the local dirt and sand has been contaminated with seawater.

The second thing is that some of your water will stay in the sand - the sand will remain wet. So you will lose some water when you use this technique. If you have a major source of water, then this may not matter at all. But if you have a very limited water supply, then you may not want to lose some to the filter. In that case, it may make more sense to filter impurities (dirt, algae) with some layers of cloth.

Pete #2

Montanero ... a bit more information on charcoal. It seems that the 2 advantages of charcoal is that it has a tremendously high porosity and it does quite a good job of absorbing organic chemicals. The high porosity means that it has a high "active surface area" - which simply means that even a small amount of charcoal has a lot of internal sites where chemicals can attach to the surface. Although basic charcoal will work, companies often take it and subject it to further processing. This produces "activated charcoal" which has even higher porosity, and it also has a special surface treatment that increases the ability of chemicals to bind to the surface.

Besides water filtration, charcoal is used medically (medicinal charcoal) to absorb poisons from the stomach and intestines. Doctors give it to patients for that reason.

I have been looking to see if i can find any information about charcoal produced by burning different kinds of woods. I have been wondering about whether the charcoal from a certain type of wood might be superior. I am just curious about how best to produce useful charcoal from a campfire. But I haven't found any good sources of info yet.

cheers,
Pete #2

Here is some basic information on activated charcoal:

Activated Charcoal

Pete

I produce a fair amount of agricultural charcoal (biochar) to improve the soil in my garden. It's incredibly simple to make. You burn wood through the "gas" phase and then deny oxygen so it can't burn in the "carbon" phase.

In practical terms: make a fire in a safe pit, keep adding wood, and continually tamp down the pieces that have stopped burning vigorously and have turned to carbon. Than, dampen it slightly, cover to exclude all oxygen, and let it sit until cold.

You can also heat wood that's stuffed inside a closed (not sealed) vessel. You'll get less ash this way. An uncoated tin can with a foil cover is an easy way to experiment.

Activation of the charcoal is a separate process, and I'm not sure a backyard setup could do this effectively. Though since my charcoal finishes while exposed to some steam and some CO in a sealed environment, I wouldn't be surprised if it is activated to some degree (can't prove it though).