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February 05, 2009

Waterproof Sand Could Green the Deserts


Waterproof sand – or as German scientist Helmut F. Schulze calls it – hydrophobic sand, a nanotechnology wonder seven years in the making.

By simply laying down a 10-centimetre blanket of DIME Hydrophobic Materials sand beneath typical desert topsoils, the new super sand stops water below the roots level of the plants and maintains a water table, giving greenery a constant water supply. 3000 tons/day is already being produced. 1 ton of silicate coated sand would probably be good for 10 square meters. 4 days of production to cover one square kilometer. More factories will be needed made to scale this up to address the water crisis in the Middle East, Africa, India and China.

So the sand is inside polyethylene sheets like this roll of fiberglass insulation.

The waterproof sand is the filler.

Some people are concerned about plastic being used on such a large scale or the environmental effect of the plastic. Yet they are also concerned that plastic will sit in landfills forever. They can select a plastic that will not decompose. This is rolls of plastic with waterproof sand buried under the topsoil to create an artificial water table.

This is the first use of nanotechnology to make a major impact on a major problem. Ironically it is similar to the first product that claimed to use nanotechnology, which were waterproof/stain resistant pants. Nanotechnology could make more impact on water scarcity with emerging nano-membranes for water purification and desalination. Nano-membranes would be several times more energy efficient. They are still a few years from large scale deployment of nano-membrane desalination.


UPDATE
A new article with more pictures and other applications for the waterproof sand.

- The benefits of success are not only increased food production but also relieve geopolitical pressure for water scarcity
In the Middle East, attention is not primarily focused on issues linking water and poverty. The region is more associated with 'water conflicts' and 'rivers of fire', images that popular media are eager to adopt. Put like this, it is suggested that the main problems with water in the Middle East are related to tensions among countries generated by water scarce environments.

Better water management can mean less poverty and few wars in the middle east and many other countries with water scarcity

- Lester Brown, environmentalist, indicates, water scarcity may be the most underestimated resource issue facing the world today. As world water demand has more than tripled over the last half-century, signs of water scarcity have become commonplace. Some of the more widespread indicators are rivers running dry, wells going dry, and lakes disappearing.

- Eighty-five percent of the water in the MENA (Middle East and North Africa) region is used for irrigation and that is potentially the main area from which the growing urban demand can be met.

- Saving 75% of water from irrigation could save millions of lives and prevent a massive humanitarian disaster and regional chaos with water wars.



So water scarcity get mitigated and regional poverty (from more local agriculture) gets reduced and the chance and probably the amount of water wars will be less.
END UPDATE

The large rolls sandwich the sand between layers of polyethylene and can be produced in lengths of up to 50 metres. “The coating is done in 30 or 45 seconds,” said Hareb. “We have the capacity of manufacturing 3,000 tonnes per day.”

The plant is ready to meet the demands of potential customers such as Dubai Municipality which has inquired about the product as it works toward greening the Emirate from the current 3.7 per cent of total landscape to eight per cent by 2015.

By simply laying down a 10-centimetre blanket of DIME Hydrophobic Materials sand beneath typical desert topsoils, the new super sand stops water below the roots level of the plants and maintains a water table, giving greenery a constant water supply.


By comparison, when regular desert sand lies beneath, water bleeds endlessly downward leaving roots dry until the next watering.

With new hydrophobic sand in place, traditional watering of desert plants five or six times a day can be reduced to one watering, saving 75 per cent more water, a precious resource that is dwindling across the Arab Peninsula.

One of the advantages of the hydrophobic sand, Schulze said, is that while it allows aerobic activity to move upward from the soil, it prevents underground desert salinity deposits from passing through to plant roots above; salt is corrosive and kills plants.

He added that each grain of sand used in the process is coated with SP-HFS 1609, a top-secret additive, the precise nature of which he declined to disclose noting that it’s proprietary.

Other forms of hydrophobic sand on the market – used for cleaning up oil spills - are coated with silicas that are water repellent.







“It’s super thin,” Schulze said. “Every single sand kernel gets a skin, a coating, which encloses it.”

The nanotechnology coating is so thin, in fact, that it can’t be seen by the naked eye and measures 12,500 to 13,500 micro millimetres.

To date, it’s been approved by the Federal Environment Agency (FEA) in Germany which, according to Schulze, has issued a no-objection certificate for the product declaring it as ecologically safe.

UAE University Professor Mohammad Abdel Muhsen Salem told XPRESS that DIME sand has been undergoing trials since December 2007 with positive results although tests are only half completed.

At the university’s College of Food and Agriculture, date palms and foreign grasses have been planted with the sand and to date, Salem said “we can see a 25 per cent increase in the roots with the hydrophobic sand compared to when just the sweet soil is used.”

Salem noted that water monitoring has also revealed that the sand conserves water.

“I’m sure it (the sand) will save up to 35 per cent more water,” he said. “But we’re still testing it.”

Tests on growing rice have just begun. If rice is successfully grown in the desert, the test will of some note given that rice is usually grown in water-soaked fields


FURTHER READING
Water scarcity and future water demand is discussed.

Water scarcity is a fact of life for 700 million people around the world, a figure that could rise to more than three billion by 2025, according to the United Nations. Over 1.6 million people die every year because they lack access to safe water and sanitation, 90 percent of them among children under five, mostly in developing countries. Diseases such as cholera, typhoid, malaria and dengue could rise due to climate change, which makes availability of freshwater less predictable because of more frequent flooding and droughts. The global population is expected to reach 8.1 billion by 2030. To keep pace with the growing demand for food, 14 percent more freshwater will need to be withdrawn for agricultural purposes in the next 30 years.


Why the HST Roll is a Good Way to Deploy the Hydrophobic Sand


Other means could be used now and might be used in future but this waterproof sand and the HST-roll delivery of it has solved most of the engineering needs and has been tested and certified and has good cost and features that are enabling large scale implementation.

Sand is important because it is super cheap. Treating the sand uses vvery little material to coat it. Sand is a normal part of ground and this is just treating it and packaging it in the currently most cost effective way and generating useful characteristics with a lot of uses.

The HST-roll method has solved a lot of the engineering challenges which may not be obvious. 3000 tons per day indicates that there is a lot of demand and that large companies are comfortable using this as a standard solution for many purposes.

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