Posted: February 5, 2009

Waterproof nanotechnology sand to help green the desert

(Nanowerk News) On a cool winter day, Emirati engineer Fahd Mohammad Saeed Hareb peers into a bubble of water atop a tiny pile of sand cupped in his hands.
Amazingly, the water bubble does not drain through the sand – it remains intact, jiggling like crystal clear Jello, under a high-noon sun.
This is waterproof sand – or as German scientist Helmut F. Schulze calls it – hydrophobic sand, a nanotechnology wonder seven years in the making.
The hydrophobic nanosand could halt desertification and turn the arid deserts of the UAE into lush greenery
The hydrophobic sand could halt desertification and turn the arid deserts of the UAE into lush greenery. (Image: XPRESS/Pankaj Sharma)
Green Dream
The scientific breakthrough may hold one more key in fulfilling the dream of Shaikh Zayed Bin Sultan Nahyan, late President of the UAE, to green the desert and beat back shifting dunes of desertification.
Shaikh Zayed “faced the problem of water shortage wisely and patiently”, said the Environment Agency of Abu Dhabi, by building enormous dams to collect rainwater, vast irrigation systems and water reclamation systems such as drip irrigation on farms.
Hareb and his family company DIME Hydrophobic Materials have joined forces with Schulze to continue Shaikh Zayed’s vision to not only green the UAE, but also to reduce water consumption by up to three quarters.
“It is my dream to make the Arab world completely green,” said Schulze from the DIME laboratory in Al Ain flanked by Hareb and product marketing partner Marco Russ of Flexon Trading Middle East.
The enthusiastic trio believe their newly adapted product could halt desertification and lead to a new life for farmers and residents by maintaining moist soils that encourage plant growth in unforgiving arid desert conditions.
Water saver
The best part about the super sand is that it is extremely user friendly.
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.
Hareb gave XPRESS an exclusive tour of the firm’s factory inside Al Ain’s industrial park where natural desert sand is subjected to a processing line, coated in a large mixer and then packaged either as loose hydrophobic product or large plastic sheet rolls.
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.
Seal of approval
DIME’s new hydrophobic sand is standing up to a battery of tests conducted by government agencies and universities in the UAE and abroad, said Schulze.
German Federal Agency for Material Research and Testing “conducted a six-month test to prove that the sand was waterproof” and in the test put the sand underneath a five-metre column of water. The conclusion was that the “sand was waterproof” and DIME said “no water was found to be lost through sand penetration”.
Al Ain’s UAE University is currently using the sand to see if rice can be successfully grown in desert conditions and the trials are still pending, Schulze said.
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.
Brandenburgische Technical University Cottbus in Germany confirmed that the DIME sand rolls can “withstand a load-carrying capacity of 104N/”.
Source: XPress (Derek Baldwin)
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