Using a bin bag, it's possible to construct a pyramidal roof above a camp fire (get an adult to help you - you may want to camp under a large tree, to suspend the bag using string from one of the lower branches).
Pop a pot of river water on said fire beneath the structure, and place a receptical at each corner of the bin bag.

Hey presto! Purifed water, ready to drink!
( Je suis un vagabond is an unfunny, up your own arse middle class knob, Wed 16 Nov 2011, 10:00, 8 replies)

Except the condensed water is now contaminated by the smoke particles from the fire.

(oneinthepink is at your cervix m'lady, Wed 16 Nov 2011, 10:38, closed)

Yes, but they're not potentially fatal, as river water might be.
They're just flavoursome.
( Je suis un vagabond is an unfunny, up your own arse middle class knob, Wed 16 Nov 2011, 10:42, closed)

Smoky water
Use it to boil your unsmoked bacon.
( .Yeti. El amor en los tiempos del cólera, Wed 16 Nov 2011, 10:46, closed)

why not
Filter any particles out with cloth, then just boil the water for 10 minutes?

You'd get cleaner drinkable water with none of the ash and smoke!
(Greencloud Wanted to go fishing on, Wed 16 Nov 2011, 11:15, closed)

That's what I've suggested.
This enables you to recoup all the water.
( Je suis un vagabond is an unfunny, up your own arse middle class knob, Wed 16 Nov 2011, 11:26, closed)

I suppose there could still be the risk of chemical pollution - heavy metals, fertilisers, etc.
A filtration and rolling boil only kills off organic nasties.
(oneinthepink is at your cervix m'lady, Wed 16 Nov 2011, 11:27, closed)

that's true, but...
If you really want to be fussy about it, you could use some of your fire embers to make a charcoal filter instead of basic cloth. This would be the best you could manage without a properly manufactured filter.
The condensation method may keep chemical pollutants (depending on their specific type) as they would evaporate with the water and be recaptured with the condensation. Along with the ash and shite kicked up by the fire.

I'll grant that condensation is perhaps the easiest way to desalinate sea water though.
(Greencloud Wanted to go fishing on, Wed 16 Nov 2011, 13:31, closed)

Why not
buy 6 bottles of Evian from Sainsbury's instead of ripping up expensive bin bags?
(username failed moderation, Wed 16 Nov 2011, 12:21, closed)