[HydrogenBond]

A simple water purification technique, that is totally organic, are plants. Picture this; one has a greenhouse where some tough but succulent leafy plants are designed to drink bad water. These plants will not only drink and collect the crap in the water but will sweat. We collect the purified plant sweat, high in oxygen, as pure drinking water. All you need is solar power for the plants and a solar panel or two running a dehumidifier.

[gribbon]

Hmmm...I've never heard of such a plant...

[Michaelangelica]

Originally Posted by fxzeu

There's hardly any water in the atmosphere.

Water is the main greenhouse gas.
(Water vapour retains 66% of all the heat trapped by all the greenhouse gasses-
-Tim Flannery)
Clouds are made from water.
(People are mainly water)
From wiki:-

An Atmospheric water generator (AWG) is a machine that produces pure drinking water from the humidity of the surrounding air. An AWG operates in a manner very similar to that of a refrigerated dehumidifier: air is passed through a cooled coil, causing water to condense. The amount of water that can be produced depends on the humidity, the volume of air passing through the coils, and the size of the machine.

The device is used in situations where pure drinking water is otherwise difficult to obtain or where the population demands are greater than the water tables can sustain or the water table has been or is contaminated, or for natural disaster relief.

The XDOBS Water extraction from air devices
A2WH (Air to Water Harvest Technology). Water Extraction from Air converts humidity in the air into high quality water. A2WH Works in Deserts and even better in humid areas.

MEDICINE INVENTIONS
E-MAIL
The Rainmaker
The science-fiction writer Arthur C. Clarke once wrote that "any sufficiently advanced technology is indistinguishable from magic." Case in point: this water-harvesting machine, which can pull up to 500 gal. of drinkable water per day out of thin air. Its precise workings aren't public, but they use a chemical process similar to the one that causes salt to absorb moisture from the air (and clump up your saltshaker). The water machine isn't particularly portable--it's 20 ft. long--but it will be a godsend for disaster victims or troops in desert combat.
Inventor: Aqua Sciences
Availability: Now; about $300,000
To learn more visit aquasciences.com

TIME Best Inventions 2006

Robert Cohen, Michael Rubner, and colleagues started by assembling a nano-structured film made of alternating layers of positively and negatively charged polymers and silica nanoparticles. The film's structure and a coating of waxy fluorinated silane cause water to bead on it, forming near-perfect spheres that easily roll off. To add the superhydrophilic regions (to which water droplets cling), the researchers applied a naturally hydrophilic polymer to selected areas.

In dry regions of the world, without easy access to clean water, such a material could be used for collecting water. In this application, the hydrophilic areas of the material would attract moisture in the air, collecting water drops that accumulate, until they spill over into the hydrophobic regions and roll into a collecting channel. Currently, in countries with limited access to clean water, the inhabitants typically use large polypropylene fiber meshes to harvest water from fog.

Technology Review: Super Plastic Both Attracts and Repels Water

[Michaelangelica]

April 1997

Dividing the Water

Water may seem to be everywhere, but for a rising portion of the world's population, there may soon be hardly a drop to drink -or to use for growing food, supporting industries and cities, and preserving life-giving ecosystems.
. . .
Indeed, a growing scarcity of freshwater is now an impediment to global future food security, health of aquatic ecosystems, and social and political stability.
Each year, millions of tons of grain are grown by depleting groundwater, a clear case of robbing the future to pay for the present. Competition for water is increasing-between cities and farms, between neighboring states and provinces, and between nations-as demands bump up against the limits of a finite supply.
And critical ecosystem functions such as flood protection, water purification, habitat maintenance, and the sustenance of fisheries are being destroyed by excessive damming, diversion, and pollution of rivers.
. . .
As world population expands by a projected 2.6 billion people over the next 30 years, and as consumption levels spiral upward, water problems are bound to intensify. With the best dam sites already developed and many rivers and groundwater reserves already overtapped, opportunities to solve these problems by exploiting new sources are limited.
A fresh approach is needed, one focused on using water more efficiently and allocating it more equitably.
. . .
humanity is already appropriating, directly or indirectly, more than half of the water supply that is now accessible.
The problem is that water use tripled between 1950 and 1990 as world population soared by some 2.7 billion.
Given that the population is projected to climb by nearly the same amount over the next 30 years, this is a troubling prospect.
Worldwide demand for water cannot triple again without causing severe shortages for crop irrigation, industrial use, basic household needs, and critical life-supporting ecosystems.

Technology Review: Dividing the Water

[gribbon]

I looked at your link, and one thing I noticed is that the site claims that these devices can be powered entirely from desert heat...quite impressive...

The trouble is though, is that only around 0.004% of the world's water is contained in the atmosphere. Over 77.20% is in the polar ice caps, but I dread to think of the practical costs regarding pumping fresh water all over the world!

Groundwater has the second most, with 22.26% of reserves, and significantly below this are the rivers and lakes, with 0.32%, and then soil.

I think the real advantage with what you propose though, is that moisture can be extracted as fast as one wants it, and there is no need to carefully moniture the extraction rates.

What we need is to compare the cost of desalination with the cost of groundwater extraction, and extraction from the atmosphere, and if possible, from glaciers and ice-caps. (Though this last one seems a bit unrealistic).

Somehow, we then need to take countries which do have water shortages and are very poor (we know that a rich country can afford desal), and see how much water they are lacking/could do with. (A few examples where water wars/ brikmanship have taken place would be between Angola, Botswana and Namibia, Israel and Egypt, Egypt and Ethiopia, Syria and Turkey, Jordan and Saudi Arabia, India and Bangaldesh, Libya and Egypt etc.

Thankfully, Qaddafi's ingenious irrigation schemes, such as his man-made river project, are going to lessen the impact of continuing popualation growth, at least for Libya.

"In general a country with less than 1,700 cubic meter per capita is regarded as experiencing water stress, while less than 1000 cubic meter is regarded as water shortage."

According to:

WaterWars

The next bit is according to:

Statistics that show water availability in each country:

So, as we can see, all the countries below China have water stress, and all the countries from Uganda downwards have a water shortage. Now someone who doesn't mind doing maths needs to calaculate how much it would cost for each one of them to make up the extra amount, fistrly if they were to use Desal, and then with the other methods. It costs 40 cents per cubic metre to desal. I'll take an example of one country that not only has severe shortages, but also has a chance of starting a war over it:

Namibia:

Would require an extra 1701.94 thousand cubic metres. So, using desal, they would have to fork out about $71,607,760

That's alot...

[Michaelangelica]

I think if there is a mathamatician around the amount of available fresh water on the planet will not be enough to go around in 2050 (Unless we have major technological breakthrough)

see also
http://hypography.com/forums/general...tml#post157462

[TheBigDog]

Originally Posted by Michaelangelica

I think if there is a mathamatician around the amount of available fresh water on the planet will not be enough to go around in 2050 (Unless we have major technological breakthrough)

see also
http://hypography.com/forums/general...tml#post157462

There is more than enough water, and there will continue to be more than enough water. The issue is not quantity, it is distribution. People need to move to the water. Infrustructures need to be built to supply water to city centers. It is a matter of engineering and political will.

Bill

[Michaelangelica]

Originally Posted by TheBigDog

There is more than enough water, and there will continue to be more than enough water. The issue is not quantity, it is distribution. People need to move to the water. Infrustructures need to be built to supply water to city centers. It is a matter of engineering and political will.

Bill

Here is a site with some sums
Human Appropriation of the World's Fresh Water Supply
A few quotes from it:-

< 1% of the world's fresh water (~0.007% of all water on earth) is accessible for direct human uses.
This is the water found in lakes, rivers, reservoirs and those underground sources that are shallow enough to be tapped at an affordable cost.
Only this amount is regularly renewed by rain and snowfall, and is therefore available on a sustainable basis.

The water cycle on Earth is essentially a closed system – we always have the same amount of water.

Worldwide, new dams (> 15 m ht) were constructed at rate of 885 per year during 1950-80, present rate is 500/yr, and future rate is estimated at 350/yr.
Over next 30 years, assuming size of reservoirs is unchanged, new construction adds 1200 km3 to accessible supply, and raises total AR in 2025 to 13,700 km3/hr.
Assuming average per capita water demand stays unchanged, but adjusting the pollution dilution for additional population, the total human appropriation in 2025 would be 9830 km3/yr, or 70% of estimated AR (compared to current 54%).
Clearly we are approaching the limit of available fresh water supply.

If all the Earth's water fit into a gallon jug, available fresh water would equal just over a tablespoon.
And the little bit we have is heavily used and abused by humans. We spend billions of dollars and tons of fossil fuels piping fresh water to semi-arid deserts such as Southern California only to flush it down the sewer at six gallons a wee. We befoul rivers and streams and oceans with all manner of toxic effluent, making them life-threatening to swim or surf in. We suck up ancient ground water supplies to grow yuppie tomatoes in November or water golf courses in the Sahara. As planetary stewards, we suck.

Surfrider Foundation Snowrider Project

[HydrogenBond]

I don't think we are running out of water or that there is not enough water to water the populations of the future. The problem is that too many people are settling where clean water is scarce. This can be due to circumstance, jobs, etc.. One can probably put a billion people around the great lakes in the US/Canada. The amazon river basin could handle 2 billion. We can dam huge retaining lakes in all the rain forests for storage and export. That buys us another 50 years.

[Zythryn]

The issue this doesn't take into affect is improvements in technology. Both recycling and desalination (sp?).
For example, if we find an economic way to turn ocean water into fresh water, supply goes way up.
Also, how is per/capita usage figured. Everyone in the world doesn't use as much fresh water as those in water plentiful regions. If water usage is brought under control, then it is simply a matter of distribution, as Bill said above.