Sciencemadness Discussion Board

I looking for something,,,,,

FEBA - 28-12-2004 at 15:10

I looking for membrane, filter or separator (something) with follow characteristic:

1- Two different fluids, oil and water; separate for somethyng , the oil in big quantities and water in small quantities . Each fluid loceted in different side.

2- The separator is not oil-permeable but it is water- permeable .Therefore, the water permeate from its side to oil side.

3- The oil side have pressure of 100 psi and water side haven't pressure.

Marvin - 29-12-2004 at 05:36

Why does this post not surprise me.

Unlike the previous posts though, this has a simple answer. Its impossible.

If the water and oil are insoluable in eachother you have no osmotic pressure and the water will not move into the high pressure oil section. You have 100psi preventing it.

mick - 29-12-2004 at 13:12

I agree
mick

mick - 29-12-2004 at 15:10

Has anyone got any ideas on purifing water to drink or for medication, if it full of shit and dead bodies.
mick

runlabrun - 29-12-2004 at 15:23

there is a type of filter paper by Whatman which was designed to seperate polar and np mixtures, i cant seem to find the page with the info on it but im sure if you search the whatman site you will find them...

But the system would not handle 100psi....

-rlr

neutrino - 29-12-2004 at 17:22

mick: IIRC, a mixture of salt and sugar is used for something like this.

Geomancer - 29-12-2004 at 20:12

mick: I assume you're asking hypothetically. As you know, an unusual number of people find themselves in this situation at the moment, but most don't have internet access.

Physical methods are the ones that are always available. Boiling is good. Fuel may be a problem; burn the shit and dead bodies if you must, and try to use/rig an effecient stove. Distillation has the advantage of being the only method that can separate salt water. Especially usefull are solar designs, such as covering a hole in the ground with a plastic sheet, putting a rock in the middle, and letting the drips collect in a container at the bottom. The capacity of this system is low, though. Filters have advantages but improvised filters leave a bit to be desired. Your best bet would be to filter through unglazed ceramic pots. Prefilter (cloth and/or sand) the water to prevent premature clogging, and clean clogged filters by scrubbing/abrading the inner surface. UV light works if you have enough of it.

The chemical methods usually used by individuals and small groups are iodine and chlorine. Any source of either (bleach, pool chlorine, betadine, iodine tincture, elemental iodine) will work in a pinch, the amount and time required depending on temperature and how dirty the water is (filter out the dead bodies before trying to disinfect the water). The other day, I saw a device that claimed to produce a chemical disinfectant by electrolysing brine. The resulting solution was to be dumped immediately into your water.

If you're looking for clever new methods, I don't have any. I suspect that getting water as disaster victims (as opposed to people who live all their lives without a good water source) must rely on judicious application of the above.

nutrino: I think you're confused. Sugar and salt will only help feed pathogens. Packets containing a mixture of salts (K, Na, Cl, and carbonate or bicarbonate come to mind) are given out to treat dehydration. A small amount of glucose (or perhaps other simple sugars) is needed to help absorb the salts. The mixture is then dissolved to make a weak solution. These are especially helpful in situation such as mick mentioned, where a shortage of clean water is compounded by a surplus of dirty water, and the diarheal diseases that go along with it.

[Edited on 30-12-2004 by Geomancer]