Activated charcoal to filter water

[bulrush]

About 2 months ago someone posted that you could make activated charcoal in the field to filter water. The user did not post any technical references proving his point so I disagreed, assuming making activated charcoal (as opposed to normal charcoal) was a highly technical undertaking.

I was wrong and I apologize.

Yesterday I saw vol 2 of "Rough Science" where 6 scientists go into the wilderness (ok they were in cabins) and have to purify water. This was their only water supply in the desert near Death Valley. And yes they made activated charcoal. To test it they make 2 foot water columns out of 1 inch clear plastic hose. They put crushed activated charcoal in it, and put dyed water in the top end. Out the bottom of the hose came clear, pure water.

For making the charcoal they put wood in a sealed metal container with a small hole, and cooked it, thus denying the charcoal oxygen. When the charcoal was "almost done" they opened the bucket to let oxygen in. This exposure to oxygen at the last minute created many more holes and pockets in the charcoal, thus drastically increasing the surface area of the charcoal and making it "activated". They did not give any more details on how to tell when you should open the bucket while making charcoal.

I would be highly interested in learning exactly when to expose the charcoal to oxygen, to make sure it becomes activated. I would also be very interested as to the effectiveness of the AC in filtering out pathogens, dissolved heavy metals (lead, arsenic, zinc, other bad stuff), pesticides, herbicides, and other industrial chemicals which are highly prevalent in my area (the 2 most polluted streams in Michigan are within 3 miles of my house).

Can anyone provide requested information?

[Ken]

Bulrush, this was a great post - got me looking around. This site has some good info:

http://www.joyfullivingservices.com/activatedcharcoal.html

I think I'm going to start playing with activated charcoal. :)

[Rick]

Activated charcoal is great for clearing water of turbidity, odor and improving the taste. It adsorbs (chemically bonds. The molecules stick to the surface) many organic contaminants and chemicals such as chlorine. But be careful, some chemicals don't bond with carbon. However, it does not purify the water from pathogenic cysts such as ghiardia.

Here is a way to make it:

http://wassupcom.1.forumer.com/index.php?showtopic=1748

[LeaveThisLifeGuy]

hmmmm, guess i'll stick to my purification tablets. the last time i had ghiardia was two weeks i never want to relive.

[crashdive123]

Ghiardia. Got me to thinking. I'll bet we could market a "Wilderness Survival Diet". All of the "pretty" folks in Hollywood would go for it. Water containing ghiardia packaged in 16 ounce bottles - guaranteed weight loss program.

[bulrush]

Crash, you got that right. I don't know what I had but I had 4 weeks of misery. I don't think food poisoning lasts 4 weeks, so I assume it was crypto. Stayed home from school for all 4 weeks because I had to use the bathroom every 5 minutes. No point in going to school if I just had to stay in the bathroom.

[Rick]

When my son was on the AT he hiked for a short time with a guy that drank raw water. I don't know how long he had been lucky but after about the 3rd day my son hiked with him the guy hobbled into the nearest town to find a doctor. My son said he'd never seen anyone that sick or go that often.

I would imagine the PCPs in and around those trails see some illnesses most doctors won't see in years if practice.

[crashdive123]

When I was living in the PNW a friend was stricken ill from ghiardia. Before he was sick - 6 ft, 4 in tall and 245 lbs. Eleven weeks later 165 lbs and on IV's to stay hydrated.

[deserttoad64]

In my younger days I worked for the Dept. of Fisheries for Washington State. I had to roam three counties walking creeks and rivers. I never carried water. I drank from what was available. As these areas were never around an urban area I didn't have too much worry about pollution from people/septic. I always picked an area where the water ran shallow over gravel for at least 100 to 150 yards. I checked to make sure there were not anything dead or floating in the water such as fish during the spawn. When the water started to slow or pooled it was a good idea to stay clear. If in doubt, dig a small hole 6 feet awat from the stream on a gravel bar and let the water seep thru and fill the hole. When any sand or dirt has settled, take a drink.
This always worked for me. My nephew drank from a dank, deep pool with floating leafs and ended up with beaver fever for months. Got to be careful.

[Rick]

Welcome, desertoad. Why not go over to the Introduction section and tell us a bit about yourself.

[DOGMAN]

ended up with beaver fever for month

I thought if it lasted for more than 4 hours you should seek immediate medical attention.:D:D:D

[Leon]

Thats some really good info - water is a serious issue if your lost or in any other survival situation, even if you prepared you might lose or run out of tablets and this is an easy method that should be available to anyone, if you can't find a metal can you could just make an old fashioned charcoal pit/hut out of wood/earth.

While its less than perfect in a pinch im sure it will be damned useful!

[Leon]

To quote that above linked article:

"Medical researchers acknowledge that charcoal is probably the best known antidote for poison"

Good to know :)

[Rick]

Remember that at the molecular level, SOME chemicals will aDsorb to carbon. So the "poison" will bond to carbon and pass through the system without being aBsorbed by your system. Not true of all poisons, of course. Always best to contact a poison control center if at all possible. The Poison Help hotline is 1-800-222-1222.

We also have a thread about how to boil water if you don't have a metal can available.

http://www.wilderness-survival.net/forums/showthread.php?t=756&highlight=boil+water

[bourne]

If I might ask - what is the recommended ratio of AC to water?

[Rick]

bourne - I would be surprised if anyone can come up with a recommendation. It would depend on a lot of factors including the material the charcoal is made of, surface area, pore size, temperature, the pH, the contact time (flow rate), and the ash content. All would increase of decrease the ability of the carbon to clear the water. The amount of contaminates in the water would also impact the amount of water the charcoal could purify.

Carbon filters, like Brita or some other commercial filter, have controlled environments for the manufacture of charcoal and since they are generally purifying tap water they can calculate the amount of water their filter can be expected to purify.

Just my thoughts on the subject.

[Ken]

bourne - I would be surprised if anyone can come up with a recommendation. It would depend on a lot of factors including the material the charcoal is made of, surface area, pore size, temperature, the pH, the contact time (flow rate), and the ash content. All would increase of decrease the ability of the carbon to clear the water. The amount of contaminates in the water would also impact the amount of water the charcoal could purify.

Carbon filters, like Brita or some other commercial filter, have controlled environments for the manufacture of charcoal and since they are generally purifying tap water they can calculate the amount of water their filter can be expected to purify.

Just my thoughts on the subject.


GASP! :eek: I am told that you are entirely correct on all points, Rick. :o * Did I just say that? *

Organic and inorganic contaminates present in the untreated water, turbidity, and temperature are all among factors to be considered. In most cases, charcoal filtering alone will not render untreated water safe to drink unless it was already naturally free of other contaminants. Sadly, most municipal water suppliers still do not (and cannot) treat for a wide array of chemical (inorganic) contaminants which may potentially enter the supply and emerge at your kitchen faucet. This is one reason why many municipal suppliers test both raw and treated water for a wide range of contaminants several times each day.

Boiling water will only render biological hazards inactive - it has no effect on chemical contaminates whatsoever. Even distillation cannot guarantee absolutely pure water depending on its source.

Industrial producers and otherwise illegally dumped waste "upstream" (including discharged inorganic contaminants and those deposited by rain, wind, and "nighthaulers") and those which leach into aquifers continue to present more longterm health risks to consumers. Understandably, extremely high levels of toxins may have an accute effect. :mad: