Expedient Water Filtration (in emergency) -- hardwood charcoal acceptable sub for activated?

self | 7/28/09 | NewJerseyJoe

[NewJerseyJoe]

I'm looking into making expedient water filtration (i.e., with found materials) under emergency circumstances.

Would crushed hardwood charcoal –– the real stuff, not "briquettes" like Kingsford –– make an acceptable filtration material, if one doesn't have access to activated charcoal? This assumes, of course, that other rules of water filtration are followed –– straining out debris, boiling after filtering, etc.

I know there is a difference at the molecular level -- activated charcoal is highly porous, creating a huge surface area. But in an emergency, hardwood charcoal might be all that's available.

[NewJerseyJoe]

I figure that, between the two of you, you’ll know the right people to ping on this topic. Thanks.

[oyez]

Charcoal has to heated to about 750 C in an inert atmosphere to become “activated”.

[NewJerseyJoe]

To clear up the original query: I'm referring to emergency scenarios -- a circumstance where you might find yourself out in wild with little more than clothes on your back.

One can make charcoal in the field; my understanding is that activated charcoal requires a bit of tech and certain chemical supplies to make properly.

So, to reiterate -- for expedient water filtration (def: "a means devised or employed in an exigency") -- would you use hardwood charcoal for filtration, where you would use activated carbon under normal circumstances?

[JRandomFreeper]

Bucket full of fine sand to filter out the junk and either bleach or idodine(blech) tabs to kill nasties. Depending on the water source, I might boil it as well. Aerate boiled water for palatablility.

BTW, you can boil water in a paper sack (honestly, try it sometime), so just because you don't have pots and pans, don't assume you can't boil water. Filtration and boiling is fairly safe.

/johnny

[seowulf]

The only difference between activated charcoal and charcoal is surface area, created by very high pressure, dry steam that blasts pores into the charcoal.

The higher the surface area the more efficient removal of organic contaminants the charcoal has.

If you use regular, homemade charcoal grind it up as small as possible to increase surface area and use more of it. It would work.

Remember, charcoal will not remove ionic species such as heavy metals or salts. It will only remove organic contaminants like solvents. If your worried about living critters, boiling is better.

[Errant]

Improvised Water Filter Part 1

There is a part 2 as well as many other videos Dave has created and posted. Many are very good.

[Cold Heart]

Scroogle an article “Using Granulated Wood Charcoal as a filter” They compare GWC favorable to Activated charcoal and superior to sand filtration. The article was talking about cleaning up waste water.

I’ll check back see if anyone else comes up with anything.

[Domandred]

http://www.therangerdigest.com/Tips%20Tricks/22%20fil%20and%20pur%20water/22%20fil%20and%20pur%20water.htm

[Bean Counter]

If you plan on boiling your water anyway, using activated charcoal to filter it first is overkill. Activated charcoal is great for removing impurities from liquids like fusal oils from alcohol, but filtering drinking water through activated charcoal is not necessary.

You can build a relatively simple, plastic barrel based sand filter that will remove most of the stuff you want out anyway, and boiling will take care of the rest. You can always purify with chlorine bleach or a proper amount of swimming pool chlorinator chemical as well.

[SpaceBar]

The short answer is no. You want to construct a sand column filter. Run through a sufficient length of clean packed sand (preferably silica) to remove particulates, then dose it with chlorine bleach or boil for consumption. Charcoal is used mainly to remove objectionable but otherwise harmless components like tannins and some volatile organics that affect taste.