Australian scientists develop nanotechnology to purify water


Scientists in Australia have developed a ground-breaking new way to strip impurities from waste water, with the research set to have massive applications for a number of industries.

Scientists in Australia have developed a ground-breaking new way to strip impurities from waste water, with the research set to have massive applications for a number of industries.

By using a new type of crystalline alloy, researchers at Edith Cowan University (ECU) are able to extract the contaminants and pollutants that often end up in water during industrial processing.

“Mining and textile production produces huge amounts of waste water that is contaminated with heavy metals and dyes,” lead researcher Associate Professor Laichang Zhang from ECU’s School of Engineering technology said in a statement on Friday.

Although it is already possible to treat waste water with iron powder, according to Zhang, the cost is very high.

“Firstly, using iron powder leaves you with a large amount of iron sludge that must be stored and secondly it is expensive to produce and can only be used once,” he explained.

We can produce enough crystalline alloy to treat one tonne of waste water for just 15 Australian Dollars (10.8 US dollars), additionally, we can reuse the crystalline alloy up to five times while still maintaining its effectiveness.” Based on his previous work with “metal glass,” Zhang updated the nanotechnology to make it more effective.

“Whereas metallic glasses have a disordered atomic structure, the crystalline alloy we have developed has a more ordered atomic structure,” he said.

“We produced the crystalline alloy by heating metallic glass in a specific way.””This modifies the structure, allowing the electrons in the crystalline alloy to move more freely, thereby improving its ability to bind with dye molecules or heavy metals leaving behind usable water.”Zhang said he will continue to expand his research with industry partners to further improve the technology.

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Map: Here’s where the world is running out of groundwater


California Ground Water Shortage 033016 GettyImages-468519400.0.0

Some of the world’s most important farming regions rely on freshwater from large underground aquifers that have filled up slowly over thousands of years. Think of the Central Valley aquifer system in California. Or the Indus basin in Pakistan and India. This groundwater is particularly valuable when rain is scarce or during droughts.

But that groundwater may not last forever. Data from NASA’s Grace satellites suggests that 13 of the world’s 37 biggest aquifers are being seriously depleted by irrigation and other uses much faster than they can be recharged by rain or runoff. And, disturbingly, we don’t even know how much water is left in these basins. That’s according to a 2015 paper in Water Resources Research.

The map below gives an overview. There were 21 major groundwater basins — in red, orange, and yellow — that lost water faster than they could be recharged between 2003 and 2013. The 16 major aquifers in blue, by contrast, gained water during that period. Click to enlarge:

World WAter Short Map 033016 uci_news_image_download

 

(UC Irvine/NASA)

The researchers found that 13 basins around the world — fully one-third of the total — appeared to be in serious trouble.

Eight aquifer systems could be categorized as “overstressed”: that is, there’s hardly any natural recharge to offset the water being consumed. In the direst state was the Arabian aquifer system beneath Saudi Arabia and Yemen, which provides water for 60 million people and is being depleted by irrigation for agriculture. Also in bad shape were the Indus Basin that straddles India and Pakistan and the Murzuq-Djado Basin in Africa.

Another five aquifer systems were categorized as “extremely” or “highly” stressed — they’re being replenished by some rainwater, but not nearly enough to offset withdrawals. That list includes the aquifers underneath California’s Central Valley. During California’s recent brutal, five-year drought, many farmers compensated for the lack of surface water by pumping groundwater at increasing rates. (There are few regulations around this, though California’s legislature recently passed laws that will gradually regulate groundwater withdrawals.)

The result? The basins beneath the Central Valley are being depleted, and the ground is actually sinking, which in turn means these aquifers will be able to store less water in the future. Farmers are losing a crucial buffer against both this drought, if it persists, and future droughts.

The big question: How soon until these aquifers run dry?

Here’s the other troubling bit: It’s unclear exactly when some of these stressed aquifers might be completely depleted — no one knows for sure how much water they actually contain.

In a companion paper in Water Resources Research, the researchers took stock of how little we know about these basins. In the highly stressed Northwest Sahara Aquifer System, for instance, estimates of when the system will be fully drained run anywhere from 10 years to 21,000 years. In order to get better measurements, researchers would have to drill down through many rock layers to measure how much water is there — a difficult task, but not impossible.

“We don’t actually know how much is stored in each of these aquifers. Estimates of remaining storage might vary from decades to millennia,” said Alexandra Richey, a graduate student at UC Irvine and lead author on both papers, in a press release. “In a water-scarce society, we can no longer tolerate this level of uncertainty, especially since groundwater is disappearing so rapidly.”

The researchers note that we should figure this out if we want to manage these aquifers properly — and make sure they last for many years to come. Hundreds of millions of people now rely on aquifers that are rapidly being depleted. And once they’re gone, they can’t easily be refilled.

Further reading

— Saudi Arabia squandered its groundwater and agriculture collapsed. The rest of the world should take note.

Rice University Research Team Demonstrates Solar Water-Splitting Technology: Renewable Solar Energy + Clean – Low Cost Hydrogen Fuel


riceresearch Solar Water Split 090415Rice University researchers have demonstrated an efficient new way to capture the energy from sunlight and convert it into clean, renewable energy by splitting water molecules.

The technology, which is described online in the American Chemical Society journal Nano Letters, relies on a configuration of light-activated gold nanoparticles that harvest sunlight and transfer solar energy to highly excited electrons, which scientists sometimes refer to as “hot electrons.”

“Hot electrons have the potential to drive very useful chemical reactions, but they decay very rapidly, and people have struggled to harness their energy,” said lead researcher Isabell Thomann, assistant professor of electrical and computer engineering and of chemistry and materials science and nanoengineering at Rice. “For example, most of the energy losses in today’s best photovoltaic solar panels are the result of hot electrons that cool within a few trillionths of a second and release their energy as wasted heat.”

Capturing these high-energy electrons before they cool could allow solar-energy providers to significantly increase their solar-to-electric power-conversion efficiencies and meet a national goal of reducing the cost of solar electricity.

In the light-activated nanoparticles studied by Thomann and colleagues at Rice’s Laboratory for Nanophotonics (LANP), light is captured and converted into plasmons, waves of electrons that flow like a fluid across the metal surface of the nanoparticles. Plasmons are high-energy states that are short-lived, but researchers at Rice and elsewhere have found ways to capture plasmonic energy and convert it into useful heat or light. Plasmonic nanoparticles also offer one of the most promising means of harnessing the power of hot electrons, and LANP researchers have made progress toward that goal in several recent studies.

riceresearch Solar Water Split 090415

Rice University researchers have demonstrated an efficient new way to capture the energy from sunlight and convert it into clean, renewable energy by splitting water molecules. Credit: I. Thomann/Rice University 

Thomann and her team, graduate students Hossein Robatjazi, Shah Mohammad Bahauddin and Chloe Doiron, created a system that uses the energy from hot electrons to split molecules of water into oxygen and hydrogen. That’s important because oxygen and hydrogen are the feedstocks for fuel cells, electrochemical devices that produce electricity cleanly and efficiently.

To use the hot electrons, Thomann’s team first had to find a way to separate them from their corresponding “electron holes,” the low-energy states that the hot electrons vacated when they received their plasmonic jolt of energy. One reason hot electrons are so short-lived is that they have a strong tendency to release their newfound energy and revert to their low-energy state. The only way to avoid this is to engineer a system where the hot electrons and electron holes are rapidly separated from one another. The standard way for electrical engineers to do this is to drive the hot electrons over an energy barrier that acts like a one-way valve. Thomann said this approach has inherent inefficiencies, but it is attractive to engineers because it uses well-understood technology called Schottky barriers, a tried-and-true component of electrical engineering.

Nanotechnology Enabled Water Treatment or NEWT: Transforming the Economics of Water Treatment


0629_NEWT-log-lg-310x310NEWT Center will use nanotechnology to transform economics of water treatment A Rice University-led consortium of industry, university and government partners has been chosen to establish one of the National Science Foundation’s (NSF) prestigious Engineering Research Centers in Houston to develop compact, mobile, off-grid water-treatment systems that can provide clean water to millions of people who lack it and make U.S. energy production more sustainable and cost-effective.

Nanotechnology Enabled Water Treatment Systems, or NEWT, is Houston’s first NSF Engineering Research Center (ERC) and only the third in Texas in nearly 30 years. It is funded by a five-year, $18.5 million NSF grant that can be renewed for a potential term of 10 years. NEWT brings together experts from Rice, Arizona State University, Yale University and the University of Texas at El Paso (UTEP) to work with more than 30 partners: including Shell, Baker Hughes, UNESCO, U.S. Army Corps of Engineers and NASA.

ERCs are interdisciplinary, multi-institutional centers that join academia, industry and government in partnership to produce both transformational technology and innovative-minded engineering graduates who are primed to lead the global economy. ERCs often become self-sustaining and typically leverage more than $40 million in federal and industry research funding during their first decade.

“The importance of clean water to global health and economic development simply cannot be overstated,” said NEWT Director Pedro Alvarez, the grant’s principal investigator. “We envision using technology and advanced materials to provide clean water to millions of people who lack it and to enable energy production in the United States to be more cost-effective and more sustainable in regard to its water footprint.”

NEWT Center will use nanotechnology to transform water treatment: Video

Houston-area Congressman John Culberson, R-Texas, chair of the House Subcommittee on Commerce, Justice and Science, said, “Technology is a key enabler for the energy industry, and NEWT is ideally located at Rice, in the heart of the world’s energy capital, where it can partner with industry to ensure that the United States remains a leading energy producer.”

Alvarez, Rice’s George R. Brown Professor of Civil and Environmental Engineering and professor of chemistry, materials science and nanoengineering, said treated water is often unavailable in rural areas and low-resource communities that cannot afford large treatment plants or the miles of underground pipes to deliver water. Moreover, large-scale treatment and distribution uses a great deal of energy. “About 25 percent of the energy bill for a typical city is associated with the cost of moving water,” he said.

NEWT Deputy Director Paul Westerhoff said the new modular water-treatment systems, which will be small enough to fit in the back of a tractor-trailer, will use nanoengineered catalysts, membranes and light-activated materials to change the economics of water treatment.0629_NEWT-truck-lg-310x239

“NEWT’s vision goes well beyond today’s technology,” said Westerhoff, vice provost of academic research at ASU and co-principal investigator on the NSF grant. “We’ve set a path for transformative new technology that will move water treatment from a predominantly chemical treatment process to more efficient catalytic and physical processes that exploit solar energy and generate less waste.”

Co-principal investigator and NEWT Associate Director for Research Qilin Li, the leader of NEWT’s advanced treatment test beds at Rice, said the system’s technology will be useful in places where water and power infrastructure does not exist.

“The NEWT drinking water system will be able to produce drinking water from any source, including pond water, seawater and floodwater, using solar energy and even under cloudy conditions,” said Li, associate professor of civil and environmental engineering, chemical and biomolecular engineering, and of materials science and nanoengineering at Rice. “The modular treatment units will be easy to configure and reconfigure to meet desired water-quality levels. The system will include components that target suspended solids, microbes, dissolved contaminants and salts, and it will have the ability to treat a variety of industrial wastewater according to the industry’s need for discharge or reuse.”0629_NEWT-mod-lg-310x239

NEWT will focus on applications for humanitarian emergency response, rural water systems and wastewater treatment and reuse at remote sites, including both onshore and offshore drilling platforms for oil and gas exploration.

0629_NEWT-log-lg-310x310Yale’s Menachem “Meny” Elimelech, co-principal investigator and lead researcher for membrane processes, said NEWT’s innovative enabling technologies are founded on rigorous basic research into nanomaterials, membrane dynamics, photonics, scaling, paramagnetism and more.

“Our modular water-treatment systems will use a combination of component technologies,” said Elimelech, Yale’s Roberto C. Goizueta Professor of Environmental and Chemical Engineering. “For example, we expect to use high-permeability membranes that resist fouling; engineered nanomaterials that can be used for membrane surface self-cleaning and biofilm control; capacitive deionization to eliminate scaly mineral deposits; and reusable magnetic nanoparticles that can soak up pollutants like a sponge.”

UTEP’s Jorge Gardea-Torresdey, co-principal investigator and co-leader of NEWT’s safety and sustainability effort, said the rapid development of engineered nanomaterials has brought NEWT’s transformative vision within reach.

“Treating water using fewer chemicals and less energy is crucial in this day and age,” said Gardea-Torresdey, UTEP’s Dudley Professor of Chemistry and Environmental Science and Engineering. “The exceptional properties of engineered nanomaterials will enable us to do this safely and effectively.”

Alvarez said another significant research thrust in nanophotonics will be headed by Rice co-principal investigator Naomi Halas, the inventor of “solar steam” technology, and co-led by ASU’s Mary Laura Lind.

“More than half of the cost associated with desalination of water comes from energy,” said Halas, Rice’s Stanley C. Moore Professor of Electrical and Computer Engineering and professor of chemistry, bioengineering, physics and astronomy, and materials science and nanoengineering. “We are working to develop several supporting technologies for NEWT, including nanophotonics-enabled direct solar membrane distillation for low-energy desalination.”

Mike Wong Lake%20ZurichRice’s Michael Wong, Yale’s Jaehong Kim and UTEP’s Dino Villagran will collaborate in efforts to develop novel multifunctional materials such as superior sorbents and catalysts, and Yale’s Julie Zimmerman will co-lead cross-cutting efforts in safety and sustainability. Rice’s Roland Smith will lead a comprehensive diversity program that aims to attract more women and underrepresented minority students and faculty, and Rice’s Brad Burke will head up innovation and commercialization efforts with private partners. Rice’s Rebecca Richards-Kortum will lead an innovative educational program that incorporates some of the “experiential learning” techniques she developed for the award-winning undergraduate research programs at Rice 360º: Institute for Global Health Technologies, and Rice’s Carolyn Nichol will lead the K-12 education efforts.

Alvarez said NEWT’s goal is to attract industry funding and become self-sufficient within 10 years. Toward that end, he said NEWT was careful to select industrial partners from every part of the water market, including equipment makers and vendors, system operators, industrial service firms and others.

NEWT is one of three new ERCs announced by the NSF today in Washington. They join 16 existing centers that are still receiving federal support, including Texas’ only other active ERC, the University of Texas at Austin’s NASCENT, as well as the other active center in which Rice is a partner, Princeton University’s MIRTHE.

0629_NEWT-Alvarez29-lg-310x465Alvarez credited Culberson and the Texas Railroad Commission for helping facilitate partnerships that were crucial for NEWT. He said the consortium’s bid to land the NSF grant was also made possible by seed funding from Rice’s Energy and Environment Initiative, a sweeping institutional initiative to engage Rice faculty from all disciplines in creating sustainable, transformative energy technologies.

“Rice’s Energy and Environment Initiative was instrumental in developing a competitive proposal, in facilitating a team-building effort and in facilitating contacts with industry to get the necessary buy-in for our vision,” Alvarez said.

Nanotechnology Enabled Water Treatment Program

LARGE_NEWTisometric

Quenching the World’s Thirst for Seawater


Carbon Nanotube 072515 I Zwitterion-snapshotEngineered carbon nanotube membranes may help solve our growing demand for desalination.

Of course, you can’t just drink a glass of water straight from the sea. But it is possible to use water from the ocean once the salts are removed. In fact, desalination plants already provide much of the water used by people in many parts of the world, especially in Israel, Saudi Arabia, and Australia.

Climate change is only increasing the demand for desalinated water as greater evaporation and rising seas further limit freshwater supplies for a growing world population. But desalinating water today comes at a very high cost in terms of energy, which means more greenhouse gases and more global warming.

Researchers from the University of Malaya’s Nanotechnology and Catalysis Research Center in Kuala Lumpur in Malaysia say in the journal Desalination that carbon nanotube (CNT) membranes have a bright future in helping the world’s population meet the need for purified water from the sea.

“Currently, about 400 million people are using desalinated water and it has been projected that by 2025, 14 percent of the global population will be forced to use sea water,” said Md. Eaqub Ali, corresponding author of the paper presenting the current problems and future challenges in water treatments.

Existing desalination plants rely on reverse osmosis, vacuum distillation, or a combination of the two, he explained. But those methods are energy intensive, and that’s where the potential for carbon nanotube membranes comes in.

Carbon nanotubes are teeny tiny hexagonal tubes, made by rolling sheets of graphene, said Rasel Das, first author of the paper. They require little energy and can be designed to specifically reject or remove not only salt, but also common pollutants.

“The hollow pores of the CNTs are extremely, extremely tiny,” Ali said. “However, because of their amazing chemical and physical properties, they allow frictionless passes of water through the pores, but reject most salts, ions, and pollutants, giving us purified water, probably in its best form.” An array of carbon nanotubes (red) forming a membrane that is highly permeable to water (blue surface), but not sodium (yellow) and chloride (green) ions.Carbon Nanotube 072515 II Figure_1

 

That frictionless property is what gives CNTs the potential to purify water with so little energy. And carbon nanotube membranes come with other perks, Das added, including self-cleaning properties.

“What makes CNTs special is that they have cytotoxic properties,” he said. That means that the membranes naturally kill microbes that might otherwise foul up their surfaces. As a result, carbon nanotube membranes have the potential to last longer much longer than those in use today.

There are hurdles yet to overcome, co-author of the paper Sharifah Bee Abd Hamid said. The CNT membranes themselves are now costly to produce, especially for large-scale uses. Research is also needed to produce the membranes with pores of a more uniform distribution and size.

“Most progress in desalination research is focused on demonstrating the capability of CNT membranes at a small scale,” she said.

For larger scale operations, work is needed to produce CNT membranes on thin films or fiber cloth composites. Getting CNT membranes ready for use will require effort on material design, operational requirements, and more.

If someday, these membranes can be put to use in water-filtering pitchers or bottles, “to directly treat salty water at point of use,” Hamid says, “it is a dream come true for many.”

Did you know?

Only 2 percent of the water on Earth comes in the form of freshwater. Of that 2 percent, 70 percent is snow and ice, 30 percent is hidden underground, and less than 0.5 percent is found in surface waters including lakes, ponds and rivers.

 

World Economic Forum: Can Graphene Make the World’s Water Clean?


Graphene Water 071115 RTRDE3R1-628x330This post is part of a series examining the connections between nanotechnology and the top 10 trends facing the world, as described in the Outlook on the Global Agenda 2015. All authors are members of the Global Agenda Council on Nanotechnology.

In the 2015 World Economic Forum’s Global Risks Report survey participants ranked Water Crises as the biggest of all risks, higher than Weapons of Mass Destruction, Interstate Conflict and the Spread of Infectious Diseases (pandemics). Our dependence on the availability of fresh water is well documented, and the United Nations World Water Development Report 2015 highlights a 40% global shortfall between forecast water demand and available supply within the next fifteen years. Agriculture accounts for much of the demand, up to 90% in most of the world’s least-developed countries, and there is a clear relationship between water availability, health, food production and the potential for civil unrest or interstate conflict.

The looming crisis is not limited to water for drinking or agriculture. Heavy metals from urban pollution are finding their way into the aquatic ecosystem, as are drug residues and nitrates from fertilizer use that can result in massive algal blooms. To date, there has been little to stop this accretion of pollutants and in closed systems such as lakes these pollutants are being concentrated with unknown long term effects.

While current solutions such as reverse osmosis exist, and are widely used in the water desalination of seawater, the water they produce is expensive. This is because high pressures are required to force the waster through a membrane and maintaining this pressure requires around 2kWh for every cubic meter of water. While this is less of an issue for countries with cheap energy, it puts the technology beyond the reach of most of the world’s population.

Any new solution for water issues needs to be able to demonstrate precise control over pore sizes, be highly resistant to fouling and significantly reduce energy use, a mere 10% won’t make a difference. Nanotechnology has long been seen as a potential solution. Our ability to manipulate matter on the scale of a few atoms allows scientists to work at the same scale as mot of the materials that need to be removed from water — salts, metal ions, emulsified oil droplets or nitrates. In theory then it should be a simple matter of creating a structure with the correct size nanoscale pores and building a better filter.

Ten years ago, following discussions with former Israeli Prime Minister Shimon Peres, I organised a conference in Amsterdam called Nanowater to look at how nanotechnology could address global water issues. While the meeting raised many interesting points, and many companies proposed potential solutions, there was little subsequent progress.

Rather than a simple mix of one or two contaminants, most real world water can contain hundreds of different materials, and pollutants like heavy metals may be in the form of metal ions that can be removed, but are equally likely to be bound to other larger pieces of organic matter which cannot be simply filtered through nanopores.  In fact the biggest obstacle to using nanotechnology in water treatment is the simple fact that small holes are easily blocked, and susceptibility to fouling means that

Fortunately some recent developments in the ‘wonder material’ graphene may change the economics of water. One of the major challenges in the commercialisation of graphene is the ability to create large areas of defect-free material that would be suitable for displays or electronics, and this is a major research topic in Europe where the European Commission is funding graphene research to the tune of a billion euros. Simultaneously there are vast efforts inside organisations such as Samsung and IBM. While defects are not wanted for electronic applications, recent research by Nobel Prize winner Andrei Geim and Rahul Nair has indicated that in graphene oxide they result in a barrier that is highly impermeable to everything except water vapour. However, precisely controlling the pore size can be difficult.

Another approach taken by researchers at MIT involves bombarding graphene sheets with beams of gallium ions to create weak spots and then etching them to create more precisely controlled pore sizes. A similar approach to water transport through defects has been taken by researchers at Penn State University.

While all of the above show that graphene has prospects for use as a filter medium, what about the usual limiting issue, membrane fouling? Fortunately another property of graphene is that it can be hydrophilic, it repels water, and protein absorption has been reported to have been reduced by over 70% in bioreactor tests. Many other groups are working on the use of graphene oxide and graphene nanoplatelets as an anti-fouling coating.

While the graphene applications discussed so far address one or two of the issues, it seems that thin films of graphene oxide may be able to provide the whole solution. Miao Yu and his team at the University of South Carolina have fabricated membranes that deliver very high flux and do not foul. Fabrication is handled by adding a thin layer of graphene to an existing membrane, as distinct from creating a membrane out of graphene, something which is far harder to do and almost impossible to scale up.

Getting a high flux is crucial to desalination applications where up to 50% of water costs are caused by pressurising water for transmission through a membrane.  Performance tests reveal around 100% membrane recovery simply by surface water flushing and pure water flux rates (the amount of water that the membrane transmits) are two orders of magnitude higher than conventional membranes. This is the result of the spacing between the graphene plates that allows the passage of water molecules via nanoscale capillary action but not contaminants.Graphene Desalinate 0422 water

Non-fouling is crucial for all applications, and especially in oil/water separation as most of what is pumped out of oil wells is water mixed with a little oil.

According to G2O Water, the UK company commercialising Yu’s technology, the increased flux rates are expected to translate directly into energy savings of up to 90% for seawater desalination. Energy savings on that scale have the potential to change the economics of desalination with smaller plants powered by renewable energy and addressing community needs replacing the power hungry desalination behemoths currently under construction such as the Carlsbad Project. This opens the possibility of low-cost water in areas of the world where desalination is currently too expensive or there is insufficient demand to justify large scale infrastructure.

While more work is required to build a robust and cost-effective filtration system, the new ability to align sheets of graphene so that water but nothing else is transmitted may be the simple game-changer that allows the world to finally address the growing water crisis.

Author: Tim Harper is Chief Executive Officer of G2O Water.

Image: The colors of Fall can be seen reflected in a waterfall along the Blackberry River in Canaan, Connecticut REUTERS/Jessica Rinaldi

Earth’s Groundwater Basins Are Running Out of Water: Arabian Aquifier at the Top of the List


Water Crisis 071015 AAcOfeWOne-third of Earth’s largest groundwater basins are under threat because humans are draining so much water from them, according to two new studies. What’s more, researchers say they lack accurate data about how much water remains in these dwindling reservoirs.

The studies found that eight of the world’s 37 biggest aquifers are “overstressed,” meaning not enough water is replenished to offset the usage. Topping the list of overstressed aquifers is the Arabian Aquifer System, located beneath Yemen and Saudi Arabia, from which 60 million people draw their water.

“What happens when a highly stressed aquifer is located in a region with socioeconomic or political tensions that can’t supplement declining water supplies fast enough? We’re trying to raise red flags now to pinpoint where active management today could protect future lives and livelihoods,” Alexandra Richey, a graduate student at the University of California, Irvine, and lead author of both studies, said in a statement. [Earth in the Balance: 7 Crucial Tipping Points]

The researchers used data from NASA’s Gravity Recovery and Climate Experiment (GRACE) satellites, twin probes that make precise measurements of changes in Earth’s gravity. These gravity perturbations are influenced by changes in mass on the planet, driven by how much water has been lost.

The studies used data collected between 2003 and 2013. In addition to the Arabian Aquifer System, the most taxed aquifers are located in the world’s driest regions, the researchers found. For instance, the Indus Basin aquifer, which straddles northwestern India and Pakistan, was labeled the second-most overstressed in the world, and northern Africa’s Murzuq-Diado Basin rounded out the top three.

Groundwater pumping in California’s Central Valley is also rapidly depleting the state’s vast aquifer system, the researchers said. This overpumping is exacerbated by the extreme drought in California, which is now in its fourth year. Currently, 99 percent of California is experiencing drought conditions, and 47 percent of the state is considered to be in “exceptional drought,” according to the U.S. Drought Monitor.

“As we’re seeing in California right now, we rely much more heavily on groundwater during drought,” principal investigator Jay Famiglietti, the senior water scientist at NASA’s Jet Propulsion Laboratory, said in a statement. “When examining the sustainability of a region’s water resources, we absolutely must account for that dependence.”

The results of the second study were just as alarming, with researchers finding that there is little information available on how much groundwater is left in the world’s largest basins. In some cases, existing estimates were based on information from decades ago, the researchers said. Adding in the GRACE measurements caused large fluctuations in the estimates. For example, the “time to depletion” for the Northwest Sahara Aquifer System was estimated at anywhere between 10 and 21,000 years, the researchers said.

“Given how quickly we are consuming the world’s groundwater reserves, we need a coordinated global effort to determine how much is left,” said Famiglietti, who is also an earth sciences professor at the University of California, Irvine.

To access groundwater reservoirs, it is often necessary to dig through rock layers far below the Earth’s surface. In addition, drillers often don’t know how deep the reservoir reaches until they dig far enough to see where the moisture is no longer available. But with the world’s usable groundwater disappearing faster than it is being replenished, it is crucial to pinpoint how much water remains in the planet’s aquifer systems, the researchers said.

“In a water-scarce society, we can no longer tolerate this level of uncertainty, especially since groundwater is disappearing so rapidly,” Richey said.

Both papers were published online June 16 in Water Resources Research, a journal of the American Geophysical Union.

Tel Aviv Univeristy: “Vibrating” Nanotubes in Water Create a 300% Improvement in the ‘Rate of Diffusion’: IBM Crowd Computing to Simulate in Demonstration


UN World Water Crisis 070615 1386965848_png_CROP_promovar-mediumlargeNearly 800 million people worldwide don’t have access to safe drinking water, and some 2.5 billion people live in precariously unsanitary conditions, according to the Centers for Disease Control and Prevention. Together, unsafe drinking water and the inadequate supply of water for hygiene purposes contribute to almost 90% of all deaths from diarrheal diseases — and effective water sanitation interventions are still challenging scientists and engineers.

A new study published in Nature Nanotechnology proposes a novel nanotechnology-based strategy to improve water filtration. The research project involves the minute vibrations of carbon nanotubes called “phonons,” which greatly enhance the diffusion of water through sanitation filters. The project was the joint effort of a Tsinghua University-Tel Aviv University research team and was led by Prof. Quanshui Zheng of the Tsinghua Center for Nano and Micro Mechanics and Prof. Michael Urbakh of the TAU School of Chemistry, both of the TAU-Tsinghua XIN Center, in collaboration with Prof. Francois Grey of the University of Geneva.

Shake, rattle, and roll

“We’ve discovered that very small vibrations help materials, whether wet or dry, slide more smoothly past each other,” said Prof. Urbakh. “Through phonon oscillations — vibrations of water-carrying nanotubes — water transport can be enhanced, and sanitation and desalination improved. Water filtration systems require a lot of energy due to friction at the nano-level. With these oscillations, however, we witnessed three times the efficiency of water transport, and, of course, a great deal of energy saved.”

The research team managed to demonstrate how, under the right conditions, such vibrations produce a 300% improvement in the rate of water diffusion by using computers to simulate the flow of water molecules flowing through nanotubes. The results have important implications for desalination processes and energy conservation, e.g. improving the energy efficiency for desalination using reverse osmosis membranes with pores at the nanoscale level, or energy conservation, e.g. membranes with boron nitride nanotubes.

Crowdsourcing the solution

The project, initiated by IBM’s World Community Grid, was an experiment in crowdsourced computing — carried out by over 150,000 volunteers who contributed their own computing power to the research.

“Our project won the privilege of using IBM’s world community grid, an open platform of users from all around the world, to run our program and obtain precise results,” said Prof. Urbakh. “This was the first project of this kind in Israel, and we could never have managed with just four students in the lab. We would have required the equivalent of nearly 40,000 years of processing power on a single computer. Instead we had the benefit of some 150,000 computing volunteers from all around the world, who downloaded and ran the project on their laptops and desktop computers.

“Crowdsourced computing is playing an increasingly major role in scientific breakthroughs,” Prof. Urbakh continued. “As our research shows, the range of questions that can benefit from public participation is growing all the time.”

The computer simulations were designed by Ming Ma, who graduated from Tsinghua University and is doing his postdoctoral research in Prof. Urbakh’s group at TAU. Ming catalyzed the international collaboration. “The students from Tsinghua are remarkable. The project represents the very positive cooperation between the two universities, which is taking place at XIN and because of XIN,” said Prof. Urbakh.

Other partners in this international project include researchers at the London Centre for Nanotechnology of University College London; the University of Geneva; the University of Sydney and Monash University in Australia; and the Xi’an Jiaotong University in China. The researchers are currently in discussions with companies interested in harnessing the oscillation know-how for various commercial projects.


Story Source:

The above post is reprinted from materials provided by American Friends of Tel Aviv University. Note: Materials may be edited for content and length.

A Global Water Crisis ~ The Seawater Solution: Will Emerging Nanotechnologies Provide the Answers?


GNT Thumbnail Alt 3 2015-page-001“Imagine getting fire-hose volumes and velocities out of your garden hose. Nanotechnology could fundamentally change the economics of desalination.”

Nearly three-quarters of the Earth’s surface is covered by water, but according to the United Nations, more than 97 percent of it is saltwater unsuited for human consumption or agriculture.

The United Nations Population Fund reports that by 2025 two-thirds of the world’s projected population of 7.9 billion may live in areas where access to safe water is limited. “Every time we add a person, it’s not just the water that person consumes but also the additional water for agriculture and industry that you have to use,” says Earl Jones, director of water-scarcity solutions in General Electric Co.’s (GE) Water & Process Technologies unit.

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The removal of salt from seawater is an increasingly cost effective answer to the earth’s growing clean-water needs. By 2025, two-thirds of the world’s population may live in areas where access to safe water is limited, reports the U.N.

The removal of salt from water is emerging as one of the best solutions to the world’s water problem, analysts say. According to GOLDMAN SACH S Group Inc. (GS), desalination is a $5 billion global market, with growth of 10 percent to 15 percent a year. Water Desalination Report, a trade journal, reports that more than 12,000 desalination plants are operating World-wide, with 53 percent of the world’s desalination capacity in the Middle East.

“Today, the global capacity is about 40 million cubic meters of desalinated water per day,” says Antoine Frérot, CEO of Veolia Water, the water division of Veolia Environnement (VE). “By 2015, it will be around 70 million cubic meters per day.” Improvements in two technologies are making desalination more cost-efficient, say the experts:

The thermal process, which couples a thermal desalination plant with a power plant to provide the energy, involves evaporating water to remove salt.

Reverse osmosis, the other process, uses semipermeable membranes. About 84 percent of the world’s thermal desalination capacity, which requires more energy than reverse-osmosis facilities, is located in the Middle East, according to Water Desalination Report.  

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“We have one huge advantage in the Gulf,” says Phil Cox, CEO of International Power PLC (IPR), which builds, owns and operates thermal desalination plants in that region. “The price of natural gas is extremely low here compared with the rest of the world,” he adds. Outside the Middle East, reverse osmosis is the less expensive alternative, says Jean-Louis Chaussade, CEO of Suez Environment, a unit of Suez SA (SZE). “At our biggest reverse osmosis plants, we operate at roughly 60 cents per cubic meter of use,” says Chaussade.

Aside from GE, International Power, Suez and Veolia, other companies that construct, own and/or operate desalination systems worldwide include The AE S Corp. (AES), Crane Co.’s (CR) Crane Environmental, Siemens AG’s (SI) Power Generation unit and ITT Corp. (ITT). ABB Ltd . (ABB) provides electrical systems for desalination plants, and Met-Pro Corp.’s (MPR) Fybroc division manufactures pumps used in reverse-osmosis plants.

The motivation is there to solve the world’s water needs, the companies say. “According to the U.N., the No. 1 cause of death and illness in developing nations is waterborne diseases,” says GE’s Jones. “We have the technology to fix these problems. It’s very easy to get motivated because of the great opportunity to do good.”  

The Scale Effect  

The world’s largest reverse-osmosis plant in terms of production is Veolia Water’s Ashkelon Seawater Desalination Plant (see illustration) south of Tel Aviv, which has a daily capacity of 320,000 cubic meters per day, according to the company. The plant produces enough water to meet the needs of 15 percent of Israeli households, Veolia reports. “There is a scale effect,” says Veolia Water CEO Antoine Frérot. “At a small desalination plant, the price of water is around $2 per cubic meter. In Ashkelon, the price is 55 cents per cubic meter.”

Other big projects are in the works: General Electric Co.’s (GE) Infrastructure, Water & Process Technologies reports that it plans to open Africa’s largest seawater desalination project in Algiers, Algeria. An international consortium led by Siemens’ Power Generation unit says it plans to build the world’s largest independent water and power project in Riyadh, Saudi Arabia. Uwe Rokossa, Siemens projects sales director for new plants and services in the Middle East predicts: “We will see a continuation of big power and desalination projects.”

Steam Power and Hybrids

Thermal desalination requires steam to boil seawater, GE explains. According to GE’s Earl Jones, the most widely used thermal process is called multistage flash, which heats seawater in a brine tank, immediately converting it to steam. The resulting salt-free steam is captured, cooled and condensed, creating desalinated water, Jones reports. Since only some of the seawater is converted to steam, the process is repeated multiple times in different receptacles, each time using lower atmospheric pressures. The hybrid approach, which combines thermal and reverse-osmosis processes, is an emerging technology, according to Suez Environment, which provides the reverse-osmosis part of the first-ever hybrid facility in the United Arab Emirates. Having both techniques in one plant allows for flexibility, the company says. Suez Environment reports that when demand for electricity from the thermal side’s power plant is low, priority can be given to the less-energy-intensive reverse-osmosis process.

Another form of the hybrid approach involves having a mixture of different membranes inside a reverse-osmosis pressure vessel, says Lance Johnson, senior sales and marketing manager for Dow Water Solutions. “As the water moves down the vessel, the salt concentration increases. At the tail end, where the salinity is highest, you’d have a lower-pressure membrane than at the front end to boost productivity.

Emerging “Nano-Materials” and Membranes

Mixing high and low pressure membranes in a pressure vessel can lower cost.” Applying nanotechnology to membrane science is another promising avenue, according to GE’s Jones, who notes that membranes made out of nanotubes can process water faster than older methods. “Imagine getting fire-hose volumes and velocities out of your garden hose. Nanotechnology could fundamentally change the economics of desalination.”        

Graphene Nano Membrane 071615

Read More:

Graphene Nano Membrane 071615Nanoscale Desalination of Seawater Through Nanoporous Graphene

Oak Ridge 1 070615 graphene-desalinate-0422-waterOakridge National Laboratory: Using New Graphene Technology to Desalinate Water

 

9 Cities Running Out of Water


water 061715 california-getty*** Team GNT™ – Noteworthy as preface to this “informing article” by Mr. Frolich is that immediate solutions are going to be patchwork at best. It could be suggested that Public Policy of the last 3-plus decades , has failed horribly the citizens of California with the direction and outcomes of ‘Water Resource Policy’. We have Zero interest in debating that point.

‘And the Good News Is’ … ???? With focus being brought to bear … there are solutions for the mid and long term and we believe (Team GNT™) that “Nanotechnologies” will be at the forefront along with a directional shift in ‘Water Resource Public Policy’, in solving the looming crisis … Globally …  ***

The nine cities with the worst drought conditions in the country are all located in California, which is now entering its fourth consecutive year of drought as demand for water is at an all-time high.

The long-term drought has already had dire consequences for the state’s agriculture sector, municipal water systems, the environment, and all other water consumers.

Based on data provided by the U.S. Drought Monitor, a collaboration between academic and government organizations, 24/7 Wall St. identified nine large U.S. urban areas that have been under persistent, serious drought conditions over the first six months of this year.

The Drought Monitor classifies drought by five levels of intensity: from D0, described as abnormally dry, to D4, described as exceptional drought. Last year, 100% of California was under at least severe drought conditions, or D2, for the first time since Drought Monitor began collecting data. It was also the first time that exceptional drought — the highest level — had been recorded in the state. This year, 100% of three urban areas in the state are in a state of exceptional drought. And 100% of all nine areas reviewed are in at least extreme drought, or D3.

According to Brad Rippey, a meteorologist with the United States Department of Agriculture (USDA), California has a Mediterranean climate in which the vast majority of precipitation falls during the six month period from October through March. In fact, more than 80% of California’s rainfall is during the cold months. As a result, “it’s very difficult to get significant changes in the drought picture during the warm season,” Rippey said. He added that even when it rains during the summer, evaporation due to high temperatures largely offsets any accumulation.

A considerable portion of California’s environmental, agricultural, and municipal water needs depends on 161 reservoirs, which are typically replenished during the winter months. As of May 31, the state’s reservoirs added less than 6.5 million acre-feet of water over the winter, 78% of the typical recharge of about 8.2 million acre-feet. A single acre-foot contains more than 325,000 gallons of water. This was the fourth consecutive year that reservoir recharge failed to breach the historical average.

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The U.S. Drought Monitor is produced by the National Drought Mitigation Center at the University of Nebraska-Lincoln, the USDA and the National Oceanic and Atmospheric Administration (NOAA). 24/7 Wall St. identified the nine urban areas with populations of 75,000 or more where the highest percentages of the land area was in a state of exceptional drought in the first six months of 2015. All data are as of the week ending June 2.

These are the nine cities running out of water.

  1. Bakersfield, CA

Exceptional drought coverage (first half of 2015):72.8%

Extreme drought coverage (first half of 2015): 100%

Population: 523,994
Over the first half of this year, nearly 73% of Bakersfield was in a state of exceptional drought, the ninth largest percentage compared with all large U.S. urban areas. The possible impacts of exceptional drought include widespread crop failures and reservoir and stream depletions, which can result in water emergencies. The drought in Bakersfield has improved somewhat from the same period last year, when nearly 90% of the area was in a state of exceptional drought — the highest in the nation at that time. Like many other areas in California, however, Bakersfield has suffered through more than four years of drought, and any improvement is likely negligible. The Isabella Reservoir on the Kern River is one of the larger reservoirs in the state with a capacity of 568,000 acre-feet. The reservoir has supplied water to Bakersfield since 1953. Today, Isabella’s water level is at less than 8% of its full capacity after falling dramatically each summer since 2011.

  1. Sacramento, CA

Exceptional drought coverage (first half of 2015): 78.3%

Extreme drought coverage (first half of 2015): 100%

Population: 1,723,634

Sacramento is the most populous city running out of water, with 1.72 million residents. The city is located just north of the Sacramento-San Joaquin River Delta, a major source of water not just for Sacramento residents but for a great deal of California. The delta also helps provide water to millions of acres of California farmland. The Sacramento and San Joaquin rivers supply nearly 80 California reservoirs. With the ongoing drought, current storage levels are well below historical averages. On average over the first half of this year, exceptional drought covered more than 78% of Sacramento. The remaining area is far from drought-free, as 100% of Sacramento was in a state of extreme drought over that period — like every other city on this list.

  1. Chico, CA

Exceptional drought coverage (first half of 2015): 85.3%

Extreme drought coverage (first half of 2015): 100%

Population: 98,176

Starting in June this year, new state legislation requires Chico residents to consume 32% less water than they did in 2013. Water bills now include water budgeting information and penalizes residents with higher fees based on how much consumption exceeds the recommended amount. The new rule may be a challenge for some residents, as Chico had among the highest per capita daily water consumption in the state in 2013, according to the ChicoER, a local news outlet. According to The Weather Channel, in April of this year a jet stream shift brought rain and snow to parts of Northern California where Chico is located, a welcome relief to the area’s long-running dry spell. Despite the short-term relief, Chico still suffers from drought — an average of more than 85% of the city was in a state of exceptional drought over the first half of this year.

  1. Lancaster-Palmdale, CA

Exceptional drought coverage (first half of 2015): 87.9%

Extreme drought coverage (first half of 2015): 100%

Population: 341,219

Compared to the first half of last year, drought conditions in Lancaster-Palmdale are worse this year. Last year, nearly 80% of the city was in extreme drought and just 10% in exceptional drought. This year, 100% of the city was classified as being in a state of extreme drought and nearly 88% in exceptional drought. Many Lancaster-Palmdale residents, particularly those in the Palmdale Water District, receive their water from the district’s water wells, the Littlerock Dam, or — like many Californians — the California Aqueduct.

The Colorado River Basin is also a major water source for the region, including Las Vegas to the northeast of Lancaster-Palmdale and Los Angeles to the southwest. Rippey explained that with only three or four wet years in over a decade, the Colorado River Basin region has endured a staggering near 15-year drought. The river, which used to flow into the ocean, now ends in Mexico. Like every other city suffering the most from drought, Lancaster-Palmdale residents are subject to various water restrictions.

  1. Yuba City, CA

Exceptional drought coverage (first half of 2015): 95.4%

Extreme drought coverage (first half of 2015): 100%

Population: 116,719

Yuba City is located on the Feather River, which runs south through Sacramento. The river begins at Lake Oroville, the site of the Oroville Dam and the source of the California Aqueduct — also known as the State Water Project (SWP). The dam’s water levels reached a record low in November 2014. While water levels have increased considerably since then, they remain at a fraction of the reservoir’s capacity. More than 95% of Yuba City was in a state of exceptional drought over the first six months of the year, making it one of only five urban areas to have exceptional drought covering more than 90% of their land area. Like other areas suffering the most from drought, the proportion of Yuba’s workforce employed in agricultural jobs is several times greater than the national proportion. The drought has had considerable economic consequences in the region. Agricultural employment dropped 30.3% from 2012 through 2013, versus the nearly 2% nationwide growth.

  1. Fresno, CA

Exceptional drought coverage (first half of 2015): 100%

Extreme drought coverage (first half of 2015): 100%

Population: 654,628

All of Fresno has endured at least moderate drought conditions during the first half of each year since 2012. For the first time this year, 100% of the city was in a state of exceptional drought, up from 75% in the same period in 2014, and one of only four urban areas experiencing maximum drought conditions in their entire area. Like in many parts of California and several other cities suffering the most from drought, Fresno’s economy relies heavily on agriculture. A major source of water in Fresno is groundwater pumped from aquifers, or natural underground basins. In addition, water is delivered directly from the Sierra Nevada mountains to replenish dwindling surface water levels. Precipitation over the winter was yet again disappointing, and snowpack in the Sierra Nevada mountains was measured at a record low this past April.

  1. Modesto, CA

Exceptional drought coverage (first half of 2015): 100%

Extreme drought coverage (first half of 2015): 100%

Population: 358,172

Like several other drought-stricken cities, Modesto is located in California’s Central Valley between the Sierra Nevada mountains and the San Joaquin River, which are both essential sources of water for the region. Lack of precipitation during the area’s multi-year drought and particularly over this past winter has resulted in record-low snowmelt levels in the mountains. In addition, the San Joaquin River supplies 34 reservoirs, which together are at 39% of their capacity as of the end of May. One of the city’s major sources of water is the Modesto Reservoir, which draws water from the Tuolumne River. The reservoir is smaller than most in California. Over the past four years, the reservoir’s water levels reached their lowest point in September 2012 and are currently just below the historical average.

  1. Merced, CA

Exceptional drought coverage (first half of 2015): 100%

Extreme drought coverage (first half of 2015): 100%

Population: 136,969

Merced is in the Central Valley, an agricultural hub, which not only accounts for a considerable portion of California’s economic output, but also supports the majority of the nation’s agricultural production. The agricultural sector in the Merced metro area accounted for 13.1% of area employment, far higher than the comparable nationwide proportion of 2%.

Agricultural businesses suffer more than perhaps any other industry during severe drought conditions. Agricultural employment shrank by 12.5% in Merced from 2012 through 2013, and the drought has only worsened since then. Over the first half of 2014, exceptional drought covered 78% of Merced, one of the highest percentages in the nation at that time. Over the same period this year, 100% of the city was at the maximum drought level.

  1. Hanford, CA

Exceptional drought coverage (first half of 2015): 100%

Extreme drought coverage (first half of 2015): 100%

Population: 87,941

With 100% of Hanford covered by exceptional drought conditions, the city is tied with Merced, Modesto, and Fresno for the worst drought conditions in the nation. Like the other three cities, Hanford, too, is located in the Central Valley. In addition to statewide restrictions as well as city emergency regulations already in place, city officials adopted additional water restrictions this June, such as barring serving of water at restaurants other than by request as well as vehicle and driveway washing bans. In addition to water restrictions and crop and environmental damage, the drought has impacted the region’s air quality. According to a recent report from the American Lung Association, Hanford had nearly the worst air pollution of any U.S. city. The report identified the dry, hot summers and stagnant air as key contributing factors to high concentrations of particulate matter and smog.

By Thomas C. Frohlich