Desalination Process

This overview might prove useful: http://www.fwr.org/desal.pdf.

I'm just guessing, but it seems that RO (reverse osmosis) might be most easily scaled to your small size, and it should be fairly rapid.

For least initial cost, but not best energy efficiency: Bunsen burner, Erlenmeyer flask, water-cooled condenser, and a bit of tubing. Or a used moonshine still.... Maybe focus sunlight on it as the heat source. I can't remember the link, but there is a video of using a Fresnel lens to do this.

For portable desalination on that scale, for drinking, check out these forward osmosis products http://www.sea-pack.com/

They have a proprietary filter in these, that takes out salt and also viruses, bacteria and the dirt, for emergency drinking water situations.

Forward osmosis, though, works by using a "sports drink concentrate" to drive the process: no pumping or energy is the up side. But it also means you won't get plain water, and it means you have to have the concentrate to get it to work.

I suppose there may be some other filter system that could be applied, to get the 'gatorade' out of it, in case, say, you were saving up for a bath?

For small scale, handpowered reverse osmosis check out this model: plain water for your work at around 20X the price...

Check out the solar desalination system at http://www.greenpowerscience.com/.

Desalination requires huge amounts of energy and generates tremendous pollution. Usually desalination is used for higher capacity plants and integrated with power station. For smaller and domestic applications R.O plants are preferred.

Think in terms of the RO systems used by the cross-Atlantic rowers to provide drinkable water. Hand-operated high-pressure pumps and a small membrane system?

A 0.1 sq.mtr solar still can give 500 ml/day distilled water in most parts of India. In India you can rig one up fpr about Rs.100 (US$2)