Globalized Economy making Water, Energy and Land Insecurity Worse a New Study by the University of Cambridge Shows …. Are We Surprised?

Credit: Pixabay/CC0 Public Domain

The first large-scale study of the risks that countries face from dependence on water, energy and land resources has found that globalisation may be decreasing, rather than increasing, the security of global supply chains.

Countries meet their needs for goods and services through domestic production and international trade. As a result, countries place pressures on natural resources both within and beyond their borders.

Researchers from the University of Cambridge used macroeconomic data to quantify these pressures. They found that the vast majority of countries and industrial sectors are highly exposed both directly, via domestic production, and indirectly, via imports, to over-exploited and insecure water, energy and land resources. However, the researchers found that the greatest resource risk is due to international trade, mainly from remote countries.

The researchers are calling for an urgent enquiry into the scale and source of consumed goods and services, both in individual countries and globally, as economies seek to rebuild in the wake of COVID-19. Their study, published in the journal Global Environmental Change, also invites critical reflection on whether globalisation is compatible with achieving sustainable and resilient supply chains.

Over the past several decades, the worldwide economy has become highly interconnected through globalisation: it is now not uncommon for each component of a particular product to originate from a different country. Globalisation allows companies to make their products almost anywhere in the world in order to keep costs down.

Many mainstream economists argue this offers countries a source of competitive advantage and growth potential. However, many nations impose demands on already stressed resources in other countries in order to satisfy their own high levels of consumption.

This interconnectedness also increases the amount of risk at each step of a global supply chain. For example, the UK imports 50% of its food. A drought, flood or any severe weather event in another country puts these food imports at risk.

Now, the researchers have quantified the global water, land and energy use of189 countries and shown that countries which are highly dependent on trade are potentially more at risk from resource insecurity, especially as climate change continues to accelerate and severe weather events such as droughts and floods become more common.

“There has been plenty of research comparing countries in terms of their water, energy and land footprints, but what hasn’t been studied is the scale and source of their risks,” said Dr. Oliver Taherzadeh from Cambridge’s Department of Geography. “We found that the role of trade has been massively underplayed as a source of resource insecurity—it’s actually a bigger source of risk than domestic production.”

To date, resource use studies have been limited to certain regions or sectors, which prevents a systematic overview of resource pressures and their source. This study offers a flexible approach to examining pressures across the system at various geographical and sectoral scales.

“This type of analysis hasn’t been carried out for a large number of countries before,” said Taherzadeh. “By quantifying the pressures that our consumption places on water, energy and land resources in far-off corners of the world, we can also determine how much risk is built into our interconnected world.”

The authors of the study linked indices designed to capture insecure water, energy, and land resource use, to a global trade model in order to examine the scale and sources of national resource insecurity from domestic production and imports.

Countries with large economies, such as the US, China and Japan, are highly exposed to water shortages outside their borders due to their volume of international trade. However, many countries in sub-Saharan Africa, such as Kenya, actually face far less risk as they are not as heavily networked in the global economy and are relatively self-sufficient in food production.

In addition to country-level data, the researchers also examined the risks associated with specific sectors. Surprisingly, one of the sectors identified in Taherzadeh’s wider research that had the most high-risk water and land use—among the top 1% of nearly 15,000 sectors analysed—was dog and cat food manufacturing in the U.S., due to its high demand for animal products.

“COVID-19 has shown just how poorly-prepared governments and businesses are for a global crisis,” said Taherzadeh. “But however bad the direct and indirect consequences of COVID-19 have been, climate breakdown, biodiversity collapse and resource insecurity are far less predictable problems to manage—and the potential consequences are far more severe. If the ‘green economic recovery’ is to respond to these challenges, we need radically rethink the scale and source of consumption.”

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Explore furtherResearchers examine food supply chain resiliency in the Pacific during COVID-19 pandemic

Provided by University of Cambridge 

Improving Access to Clean Water and the Role of Nanotechnology

Access to clean, safe drinking water is thought to be a basic human right. Yet, according to the World Health Organization (WHO), over 785 million people across the globe are without access to a basic drinking-water source. This has researchers around the world researching and developing a series of water treatment solutions and applications using nanotechnology.

Current WHO statistics are damning, making this an issue that must be addressed urgently as it is thought that around 2 billion people are using a contaminated water supply. In addition, over 485,000 people die each year from diarrhoeal related illnesses and diseases such as polio, typhoid, and cholera are once again being transmitted as a further consequence. Based on current trends and data, it is thought that by 2025 half of the total global population will be living in water-stressed or water-scarce areas.

 

While there are a wide-range of effective water purification methods and techniques including boiling, filtration, oxidation, and distillation, these often require high amounts of energy. Other treatment processes may include the use of chemical agents which is only possible in areas with an infrastructure that is up to par.

The more affordable and portable devices currently available are not always fit for purpose as they cannot guarantee 100% removal of harmful viruses, bacteria, dust, and even microplastics. So, it is thought that nanotechnology could offer affordable and accessible clean water solutions to the world’s most vulnerable populations.

Nanotechnology is a process that involves manipulating and controlling matter on the atomic scale. In the process of water purification, this involves using nanomembranes to soften the water and eradicate biological and chemical contaminants as well as other physical particles and molecules.

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What’s more is that nanotechnology is portable and can be incorporated into existing commercial devices which increases the likelihood that nanotech solutions could become a feasible option for areas of the developing world and places with limited infrastructure.

In recent years scientists have improved on conventional methods that use coagulants by taking their cues from nature, notably the ocean dwelling Actinia organism. Traditional coagulants, such as aluminum sulfate and other metallic salts can pull out larger contaminants by causing them to group together and settle. However, this method is not effective for smaller particles and molecules and often requires additional methods to ensure the water is clean. Thereby increasing the cost and use of energy as several techniques are required to ensure the water is safe.

Using nanocoagulants, scientists were able to synthesize organic and inorganic matter to replicate the structure of the Actina sea anemone. The researchers produced a reversable core-shell that can catch larger particles as well as the smaller ones when it turns inside-out. This is also a one-step process which removes the need for additional technologies and opens up the potential for minimizing water purification costs.

Another viable method of water purification currently in development that makes use of nanotechnology includes utilizing magnetically active nanoparticles to extract chemicals from water. The process enables the removal of toxins from drinking-water contaminants attracting nanoparticles that consist of magnetic phases. This solution would also be low-energy and could provide an economic advantage as well as health and environmental benefits.

Other proposals for nanotech solutions include using nanoparticles to break down microplastics and a rapid nano-filter that can clean dirty water 100 times faster than current methods. Researchers are also aware that most water purification methods require access to a constant electricity supply, but this can be a significant obstacle in places with limited infrastructure or areas damaged by extreme weather conditions.

One such approach is the creation of a self-sustaining biofoam that conducts heat and electricity by combining bacteria-produced cellulose with graphene oxide. The graphene-fused foam draws water up to the surface via the cellulose layer which accelerates evaporation. This results in a layer of freshwater which can be easily collected and is safe to drink. The biofoam is also lightweight and relatively inexpensive to manufacture making it an attractive alternative to conventional methods.

Thus, as the need for clean, safe water is very much still an urgent global issue, nanotech solutions offer new and essential possibilities for the water treatment industry. The next phase of development is the scaling up of nanotechnologies to improve access to clean water. Perhaps then the future can be one that offers a new hope to the expanding global population experiencing water-stressed and water-scarce conditions.

Re-Posted from AZ NAno – David J. Cross MA

“It’s ALL .. About the WATER! 2 Maps that Show the next Potential Catastrophe Affecting the Middle East: Solving the World’s Water Crisis

 

As sectarian strife spearheaded by ISIS convulses the Middle East, and tensions between Iran and Saudi Arabia only deepen, it is hard to imagine that a far more pressing concern could be threatening the region.

But a series of maps from the UN show that despite the awful suffering already occurring throughout the Middle East, things could always become significantly worse. The central issue that will affect the region, vast swathes of North and East Africa, and even Central Asia and China is the increasing strain on and lack of the world’s single most important resource — water.

The following map from the UN Water’s 2015 World Water Development Report shows the total amount of renewable water sources per capita available in each country in the world. In 2013, a number of countries — including regional heavyweights such as Saudi Arabia and Jordan — were facing absolute water scarcity.

Egypt, the most populous country in the Middle East, faced water scarcity, as did Syria and Sudan. In Sudan, the lack of water is believed to be one of the root causes of the continuing conflict in the Darfur region as various groups have continued to compete over the increasingly scarce resource.

And the UN predicts that water scarcity will only intensify. By 2030, UN Water predicts that the world will “face a 40% global water deficit under the business-as usual [sic]” scenario. This strain on water, unless proactively addressed, will only cause further inter- and intra-state conflicts.

Again, according to UN Water, “inter-state and regional conflicts may also emerge due to water scarcity and poor management structures. It is noteworthy that 158 of the world’s 263 transboundary water basins lack any type of cooperative management framework.”

Essentially, the world as it currently is will continue to face worse water crises. These crises will force states, or individuals within states, to go to extreme lengths to survive. And without significant frameworks in place, people may resort to conflict for survival.

The following map, from the UN World Water Development Report 2016, shows the proportion of renewable water resources that have already been withdrawn. The Middle East and Central Asia is again at significant risk, as the majority of countries in both regions have withdrawn more than 60% of their water resources.

 

 

 

Read More on How New (Nano) Technology Can Help Solve Our Looming Water Issues

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Nanoscale Desalination of Seawater Through Nanoporous Graphene

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MIT: Silk-based filtration material breaks barriers: Engineers find nanosized building blocks of silk hold the secrets to improved filtration membranes

A scanning electron micrograph shows a free-standing Bombyx mori silk nanofibril membrane.

Image courtesy of the researchers.

When the Chinese first discovered silk, its superior quality and properties were thought so special, it was reserved exclusively for clothing the emperor, his relatives, and dignitaries. And for more than two millennia, the mechanisms of silk production were a highly guarded secret.

Fast forward to today: MIT and Tufts University researchers have discovered additional hidden secrets of silk, called nanofibrils, which, when expertly extracted and reassembled, can be manufactured into advanced filtration membranes. The researchers’ new silk-based filtration technique was recently described and published in the paper, “Ultrathin Free-Standing Bombyx mori Silk Nanofibril Membranes” in the journal Nano Letters.

The paper reveals how silk nanofibrils (SNFs), a key nanocale building block of natural silk, can lead to new naturally-based filters that are more effective, less expensive, and “greener” compared with traditional commercial products. This discovery could portend new production methods and supply chain economics for anyone that uses the new filter membranes, including water treatment facilities, food manufacturers, and life sciences organizations.

The researchers included Department of Civil and Environmental Engineering (CEE) graduate student Kai Jin; CEE postdoc Shengjie Ling; Markus J. Buehler, head of CEE and the McAfee Professor of Engineering; and Professor David L. Kaplan, chair of the Tufts Department of Biomedical Engineering.

“There has been a renewed focus recently on developing these types of ultrathin filtration membranes which can provide maximum flow-through while retaining molecules or pollutants that need to be separated from the flow,” Ling says. “The challenge has always been to create these new ultrathin and low-cost devices while retaining mechanical strength and good separation performance. Cast silk fibroin membranes aren’t an option, because they do not have porous structure and dissolve in water if not pretreated. We knew there had to be a better way.”

An insurmountable challenge — until now

The researchers spent many months sharing ideas, working and reworking calculations, and experimenting in the lab. Their effort to find just the right solvent to dissolve the silk fibers into their most elemental compounds without destroying the samples was one of their greatest challenges.

“We devoted a lot of time developing the method for extracting the nanofibrils from the natural silk fibers,” Ling says. “It’s a novel approach, so we had to use trial and error before we eventually found success. It was such a good feeling to realize in tangible results what was calculated.”

Their work — a collaborative effort among civil, biomedical, and computational engineering, and materials science — found the solution in this new free-standing ultrathin filtration membrane and its innovative, advanced production technique.

Infinitesimal, but mighty

Natural silk fibers, which are made of pure protein, are renowned for their incredible lightness, strength, and durability. The silk nanofibrils used by the researchers were exfoliated from domesticated silkworm-produced fibers. It is the special character of the silk nanofibrils that helps the innovative membranes retain their exquisite structure and superior physical properties.

Historic methods to extract or prepare these nanofibers have not always worked. The illustration in the slideshow above shows the researchers’ unique four-step approach that proved effective by overcoming prior hurdles. The first two steps were used to exfoliate the silk nanofibrils from the silk fibers by degumming, washing, drying, and incubating them at a constant temperature, before placing them in water and stirring or shaking them to remove any undissolved silk. The third step involved using ultrasonic waves to extract the silk nanofibrils, which remained stable over several months. Scanning electron micrograph imagery showed the silk nanofibrils had a diameter and contour length similar to the diameter of a single nanofibril strand. In the last step and final process, they assembled the silk nanofibrils into the ultrathin membranes using a vacuum filtration process.

Success came in meeting and exceeding three important membrane attributes: thickness (40-1,500 nanometers with narrowing pore sizes of 12-8 nm); superior water permeation, known as flux; and excellent broad-spectrum separation performance for most dyes, proteins, and nanoparticles. All of these mechanical superiority results are critical to industry, especially for use in pressure-driven filtration operations, even at high applied pressures.

Whether purifying waste water for drinking, or capturing the minuteness of blood clots in the human body, these new silk-based membranes offer significant advanced operational efficiencies. And one piece of silk nanofibrils membrane averages only $0.05-$0.51 compared with $1.20 per piece of commercial filtration membrane.

Silk nanofibrils used in manufacturing hold other important benefits, too. As the by-products of silkworms, innovative manufacturers who leverage silk’s natural properties can enhance their industrial ecology and produce less environmental stress. And once the filters are replaced, the used ones biodegrade, leaving no lasting impact.

A keen eye for detail

Controlling the thickness of membranes and pore size distribution is especially important for filters to work effectively, so the researchers made sure the interconnected membrane pores produced in the lab were uniform and without cracks or pinholes.

In addition, they noted the new membrane’s rejection of protein and gold nanoparticles in flow was higher than that of membranes with similar thickness. Protein molecules, colloids, nanoparticles, small molecules, and ions were all used to assess size-selectivity.

The researchers experimented frequently with water fluxes through membranes of different thicknesses (40-60 nm).

“What really surprised us,” says Jin, “is that one flux was faster than that of most commercial materials, in fact, more than 1,000 times higher in some cases.” The result proved better than fluxes of the most advanced ultrathin membranes.

Other findings showed remarkable flexibility, ease of use and sustainability. For example, the new membranes could be removed without adhering to the supporting substrate, they appeared homogeneous, were transparent with structural color on the surface, could be cut and bent without damage, and probably most important, did not dissolve in water — a critical role in most filtration processes. And because silk nanofibrils are negatively charged at neutral pH, more positively charged molecules can be taken up by the membranes via electrostatic interactions.

“These natural silkworm membranes have remarkable separation efficiency on par with current synthetic technologies,” says Professor Kristie J. Koski of Brown University’s Department of Chemistry, who was not involved in the research. “As a non-toxic, flexible, and tunable membrane, they have great potential for purification and recycling especially in applications where synthetic alternatives are not an option such as in biological systems.”

Professor Thomas Scheibel of The University of Bayreuth in Germany, who also was not associated with the study, adds: “The filter efficiency is one of the most important parameters of filter materials. This parameter is mainly influenced by the structure of the filter material. Nano silk filters are consistently filled and therefore enable the retention of quite small particles. New filter devices based thereon should allow lowering the overall energy consumption in water as well as in air filtration at constant or even higher filter efficiencies than existing ones.”

The team’s discovery reflects ways in which silk’s hidden secrets can advance civilization in multiple new ways.

Marilyn Siderwicz | Department of Civil and Environmental Engineering

Is Capacitive Deionization The Key To Desalination?

Capacitive deionization (CDI) is a process by which the ions are removed from water with the use of two electrodes. A positively charged electrode captures the water’s negatively charged anions while a negatively charged electrode captures the water’s positively charged cations.

“The technology can be best thought of as a tool which removes dissolved ionic species from a solvent using highly porous carbon electrodes charged to a small voltage,” explained Matthew Suss, assistant professor at the Israel Institute of Technology. “It works by a phenomenon known as electrosorption, where charging the porous carbon electrodes positively allows for dissolved ions of opposite charge to be brought to the pore surface and held there electrostatically. In this way, ions are removed from the water and held along the surface until the voltage is removed.”

This may seem like an abstract practice until you remember that salt is an ionic compound and that through CDI, it can be removed from water.

In the 2015 study “Water desalination via capacitive deionization: what it is and what you can expect” published by the Royal Society of Chemistry, Suss and a team of researchers take a long view at a field that has grown rapidly in the last few years, in large part because of its implications for the water industry.

“It is a highly scalable technique which does not require much energy for brackish water desalination,” he said. “To run it, you need mainly a low-voltage input, so no high-pressure pumps or heat sources are required.”

Probably the most popular desalination alternative to CDI is reverse osmosis (RO). That involves using high-pressure pumps to force water through semipermeable membranes which screen out the salt. These pumps need lots of energy to keep running and the process requires about 5 kWh to produce a cubic meter of freshwater, according to an online encyclopedia of desalination and water resources.

In contrast, a Chinese CDI operation featured in Suss’ study reported energy consumption around 1 kWh for every cubic meter of freshwater produced.

In their study, Suss and his research team put the water recovery ratio (the ratio of produced freshwater volume to feedwater volume) for a typical seawater reverse osmosis (SWRO) plant at 45 percent to 55 percent, while CDI systems have the potential to attain a ratio significantly higher than 55 percent.

However, as a relatively new technology there aren’t that many full-scale operations that utilize CDI. It’s hard to gauge how well it could perform if widely employed.

“It is a fast-emerging technology in the research world and so that is now translating to growth in the industry,” as Suss put it. “The main obstacle is the lack of demonstration plants and scaled-up systems at the moment. Most systems are lab-scale right now.”

With water scarcity propelling us to find creative solutions just so we have enough to drink, it won’t be long until CDI gets its time in the spotlight.

Image credit: “Salt,” © 2008 Kevin Dooley, used under an Attribution­ShareAlike 2.0 Generic license: http://creativecommons.org/licenses/by­sa/2.0/

MIT: Cleaning Water with Solar Energy … without “the grid”

MIT researchers have developed a solar-powered desalination system that could significantly increase the groundwater available for drinking in Indian villages.

Amos Winter may be an assistant professor of mechanical engineering at MIT, but he describes one of the most important aspects of his job as “detective work.” That’s what he, MIT PhD candidate Natasha Wright, and their fellow researchers did for two years before coming up with a potential solution to issues of clean-water access in India.

It paid off. Their research team, sponsored by the MIT Tata Center for Technology and Design and its partner, the Indian firm Jain Irrigation Systems, won the United States Agency for International Development (USAID)’s Desal Prize earlier last year with their design of a solar-powered electrodialysis desalination system.

The detective work began when Jain Irrigation pointed out that small-scale farmers in India who use Jain’s irrigation systems often lack access to safe drinking water. Winter, Wright, and others on the Tata Center team spent two years meeting with farmers and village dwellers trying to understand the reason for drinking water shortages in rural Indian communities.

They expected the villagers’ primary concern to be contamination of water by bacteria. But in their meetings, the team identified another, generally overlooked contaminant in India’s water: salt. “What can happen frequently,” Winter says, “is that people who only have access to a salty drinking source won’t want to drink [the water] because it tastes bad. Instead, they’ll go drink from a surface source like a pond or a river that can have biological contaminants in it.” By removing salt from water sources, the team could more than double the groundwater available to villagers for drinking.

The announcement of the USAID Desal Prize competition hit shortly after the team published a paper on the importance of desalination to clean drinking water. Background research already in hand, the team connected a trailer containing their prototype system to a Tata Center-supplied truck and drove it to the competition in New Mexico. And in a pool that had close to 70 applicants, they won. In fact, they were the only entry to meet all of USAID’s specifications for flow rate and salinity.

The win was game-changing. According to Winter, the Desal Prize has seriously accelerated the typical development timeline for a project like this. Winning the prize has connected him and Wright with other major players in the clean water space, and international expertise provided by USAID has put more potential locations for the new desalination system on the team’s radar. One of them is Gaza. “It’s pretty exciting,” Winter says, “because the needs and requirements for off-grid desalination [in the Middle East] are very similar to those in India.”

First, though, the team has to work out a few kinks in the technology. Winter identifies two major “pain points”: the overall materials cost of the system and the energy needed to pump water through it. The only “real necessary power” for running the system is the power required by the electrodialysis technology to separate the ions of salt from the rest of the water, Winter says. Cutting down other energy consumption would both conserve power and bring down cost.

One way to cut cost could be to wean the system off battery usage. In fall 2015, the team began researching whether their system could run effectively on solar energy without using batteries as a buffer to store energy when the sun is down. The research involves conducting pilot tests in which farmers come to one of Jain Irrigation’s test farms in India and use the system in real time. Their experience will shed light on whether demand for water throughout the day aligns with the availability of solar energy.

Winter and Wright have also just signed a three-year contract with Tata Projects, an engineering subsidiary of the Tata Group currently focusing on village-scale water systems. Tata Projects already has a well-developed reverse-osmosis water-purifying operation, but it wants to expand to off-grid communities — places where solar-powered electrodialysis desalination would be a better option. Tata Projects is also looking into the possibility of using the technology in specific subsets of urban environments, such as apartment complexes. “There are a number of market opportunities for this technology beyond just small-scale villages,” Winter says.

The work, of course, is far from done. “The research that we’re doing now, and that the Tata Center in general does, involves tackling problems in emerging markets that require high-performance but relatively low-cost solutions,” Winter says. “We don’t just say, ‘OK, we’re going to make a technology [in our lab] and then see if we can commercialize it.’ We try to understand from the start the user-centered, real-life requirements for a technology so we can design to meet them.” Not elementary at all, but certainly the work of good detectives.

MIT: Filtering Drinking Water with Nanofibers: Video

Published on Apr 21, 2016

Liquidity, an Alameda, California-based startup, has developed a low-cost water filter made from nanofibers that it hopes will reduce water-borne diseases in poor countries. A version designed for the developed world, Naked Filter, attaches to a plastic water bottle. Its membrane of electrospun nanofibers allows water to pass through it quickly.

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MIT: Researchers Create Potential “Nano-Water Filters” : Video

Researchers create perfect nanoscrolls from graphene’s imperfect form.

Water filters of the future may be made from billions of tiny, graphene-based nanoscrolls. Each scroll, made by rolling up a single, atom-thick layer of graphene, could be tailored to trap specific molecules and pollutants in its tightly wound folds. Billions of these scrolls, stacked layer by layer, may produce a lightweight, durable, and highly selective water purification membrane.

But there’s a catch: Graphene does not come cheap. The material’s exceptional mechanical and chemical properties are due to its very regular, hexagonal structure, which resembles microscopic chicken wire. Scientists take great pains in keeping graphene in its pure, unblemished form, using processes that are expensive and time-consuming, and that severely limit graphene’s practical uses.

Seeking an alternative, a team from MIT and Harvard University is looking to graphene oxide — graphene’s much cheaper, imperfect form. Graphene oxide is graphene that is also covered with oxygen and hydrogen groups. The material is essentially what graphene becomes if it’s left to sit out in open air. The team fabricated nanoscrolls made from graphene oxide flakes and was able to control the dimensions of each nanoscroll, using both low- and high-frequency ultrasonic techniques. The scrolls have mechanical properties that are similar to graphene, and they can be made at a fraction of the cost, the researchers say.

“If you really want to make an engineering structure, at this point it’s not practical to use graphene,” says Itai Stein, a graduate student in MIT’s Department of Mechanical Engineering. “Graphene oxide is two to four orders of magnitude cheaper, and with our technique, we can tune the dimensions of these architectures and open a window to industry.”

Stein says graphene oxide nanoscrolls could also be used as ultralight chemical sensors, drug delivery vehicles, and hydrogen storage platforms, in addition to water filters. Stein and Carlo Amadei, a graduate student at Harvard University, have published their results in the journalNanoscale.

Getting away from crumpled graphene

The team’s paper originally grew out of an MIT class, 2.675 (Micro/Nano Engineering), taught by Rohit Karnik, associate professor of mechanical engineering. As part of their final project, Stein and Amadei teamed up to design nanoscrolls from graphene oxide. Amadei, as a member of Professor Chad Vecitis’ lab at Harvard University, had been working with graphene oxide for water purification applications, while Stein was experimenting with carbon nanotubes and other nanoscale architectures, as part of a group led by Brian Wardle, professor of aeronautics and astronautics at MIT.

The researchers’ graphene nano scroll research originated in this MIT classes 2.674 and 2.675 (Micro/Nano Engineering Laboratory).

Video: Department of Mechanical Engineering

“Our initial idea was to make nanoscrolls for molecular adsorption,” Amadei says. “Compared to carbon nanotubes, which are closed structures, nanoscrolls are open spirals, so you have all this surface area available to manipulate.”

“And you can tune the separation of a nanoscroll’s layers, and do all sorts of neat things with graphene oxide that you can’t really do with nanotubes and graphene itself,” Stein adds.

When they looked at what had been done previously in this field, the students found that scientists had successfully produced nanoscrolls from graphene, though with very complicated processes to keep the material pure. A few groups had tried doing the same with graphene oxide, but their attempts were literally deflated.

“What was out there in the literature was more like crumpled graphene,” Stein says. “You can’t really see the conical nature. It’s not really clear what was made.”

Collapsing bubbles

Stein and Amadei first used a common technique called the Hummers’ method to separate graphite flakes into individual layers of graphene oxide. They then placed the graphene oxide flakes in solution and stimulated the flakes to curl into scrolls, using two similar approaches: a low-frequency tip-sonicator, and a high-frequency custom reactor.

The tip-sonicator is a probe made of piezoelectric material that shakes at a low, 20Hz frequency when voltage is applied. When placed in a solution, the tip-sonicator produces sound waves that stir up the surroundings, creating bubbles in the solution.

Similarly, the group’s reactor contains a piezoelectric component that is connected to a circuit. As voltage is applied, the reactor shakes — at a higher, 390 Hz frequency compared with the tip-sonicator — creating bubbles in the solution within the reactor.

Stein and Amadei applied both techniques to solutions of graphene oxide flakes and observed similar effects: The bubbles that were created in solution eventually collapsed, releasing energy that caused the flakes to spontaneously curl into scrolls. The researchers found they could tune the dimensions of the scrolls by varying the treatment duration and the frequency of the ultrasonic waves. Higher frequencies and shorter treatments did not lead to significant damage of the graphene oxide flakes and produced larger scrolls, while low frequencies and longer treatment times tended to cleave flakes apart and create smaller scrolls.

While the group’s initial experiments turned a relatively low number of flakes — about 10 percent — into scrolls, Stein says both techniques may be optimized to produce higher yields. If they can be scaled up, he says the techniques can be compatible with existing industrial processes, particularly for water purification.

“If you can make this in large scales and it’s cheap, you could make huge bulk samples of filters and throw them out in the water to remove all sorts of contaminants,” Stein says.

This work was supported, in part, by the Department of Defense through the National Defense Science and Engineering Graduate (NDSEG) fellowship program.

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

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:

 

(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.

National Science Foundation Invests in a Clean Water Future

NSF supports national efforts to bolster water security and supply. Credit and Larger Version

March 22, 2016

Today, at the White House Water Summit, the National Science Foundation (NSF) joins other federal agencies to emphasize its commitment to a sustainable water future.

Access to affordable clean water is vital for energy generation, food cultivation and basic life support. With drought pressure and population demands, water is an increasingly precious resource.

The California drought and Flint water emergency show some of the consequences of clean water shortages. Low-cost, low-energy technologies for both water quality testing and water treatment must be developed to overcome economic barriers and secure America’s future.

NSF supports national efforts to bolster water security and supply by investing in fundamental science and engineering research.

“Routine and reliable access to safe drinking water is one of the greatest achievements in human history, thanks to science and engineering research,” said Pramod Khargonekar, NSF assistant director for Engineering. “To ensure this accessibility continues, contributions from all research areas — from engineering and physical sciences to the biological and social sciences — are essential. As such, NSF is uniquely positioned to advance water innovations.”

For decades, NSF has funded researchers across disciplines to investigate fundamental water questions and propose novel solutions to challenges.

Despite the importance of water to life on Earth, major gaps exist in our understanding of water availability, quality and dynamics, as well as the impact of human activity and a changing climate on the water system. These gaps must be filled in order to create new concepts for water desalination, purification, reuse and treatments.

“To take on the most urgent challenge facing the world today, NSF and our partner agencies are funding researchers to explore interactions between the water system and land-use changes, the built environment, ecosystem functions and services, and climate change through place-based research and integrative models,” said Roger Wakimoto, NSF assistant director for Geosciences. “Through these activities, we are enabling a new interdisciplinary paradigm in water research.”

 

 

 

NSF-funded demonstrations at today’s White House event:

• An interactive augmented reality sandbox exhibit to help teach the public about watersheds, lake sciences, and environmental stewardship.
  • The project, led by NSF-funded researcher Louise H. Kellogg, is a collaboration between university scientists and pubic science centers. Partners include University of California, the Davis W. M. Keck Center for Active Visualization in Earth Sciences, the Tahoe Environmental Research Center, the Lawrence Hall of Science, ECHO Lake Aquarium & Science Center, and Audience Viewpoints.

• A novel technology that uses sound waves to isolate and remove particles from fluids.
  • Jason Dionne of FloDesign Sonics Inc. is supported by the NSF Small Business Innovation Research program to commercialize the technology, which offers a potentially more efficient and environmentally benign method to purify water.

• The launch of two “smart markets” for water leasing in the country: for groundwater trading in western Nebraska, and for surface-water trading in central Washington State.
  • Mammoth Trading is creating smart markets to automate the process of checking complex regulatory rules for trading and to generate the highest economic gains among participants. By monetizing the value of conserved water, water leases generate a potential new revenue for water users and reward innovation in water use at the farm level. Mammoth Trading’s markets will be available in over 500,000 acres of irrigated farmland. Mammoth Trading grew out of NSF-funded research, which was commercialized through the NSF Innovation Corps (I-Corps™) program.
• A book series and curriculum to teach children about the water cycle.
  • NSF supports 25 Long-term Ecological Research (LTER) projects across the country and in Antarctica to study ecological processes. The LTER network enables these sites to serve as local and regional “schoolyards” to promote understanding of environmental processes among K-12 students. One outreach tool they employ is the LTER Schoolyard Series, which includes hands-on activity guides and integrates with federal and state science standards.

New NSF investments announced today:

• $20 million to support cutting-edge water-research projects through the NSF Experimental Program to Stimulate Competitive Research program.
  • Research teams will apply a systems-based, highly integrated approach to determine when and where the impacts of extreme events cascade through the combined social-ecological system. An integrated model of the watershed will be used to test management scenarios and identify strategies for maintaining infrastructure, environmental health and drinking water quality in the face of extreme weather events.
• $2 million to educate technicians for high-technology fields that drive our nation’s economythrough the NSF Advanced Technology Educationprogram.
  • A project to enhance marine and environmental science education at the five minority-serving community colleges of the Pacific Islands.
    • American Samoa Community College, the College of Micronesia — FSM, the College of the Marshall Islands, Northern Marianas College and Palau Community College will receive support for curriculum development, faculty professional development, internships and field experiences for students, and strengthened scientific infrastructure. Robert Richmond of University of Hawaii, Honolulu is the award’s primary investigator.
  • A college course to increase student engagement and learning around the Hoosick Falls water crisis.
    • The Village of Hoosick Falls in New York recently discovered unsafe concentrations of perfluorooctanoic acid in its public water system. With NSF support, an interdisciplinary group of scientists led byDavid Bond of Bennington College will develop a course to train students in the effective use of science and technology related to water safety.

• Two workshops planned on new water technologies and systems to give new meaning to the word “wastewater.”
  • Wastewater treatment plants are not only vital to the protection of human health and the environment, but also present opportunities to recover energy and other valuable resources — creating a world-class water infrastructure while reducing the costs to run it. Recognizing this, NSF, the Department of Energy, the Environmental Protection Agency, and the U.S. Department of Agriculture, with the Water Environment Research Foundation, are developing a National Water Resource Recovery Test Bed Facility network and directory to connect researchers, new technology providers and other innovators in the water-resource recovery industry with test facilities appropriate for their needs. NSF is planning two workshops, in May and June 2016, to support the development of appropriate metrics and structure possibilities for the network.

• A new Nanotechnology Signature Initiative on water sustainability through nanotechnology.
  • Federal agencies participating in the National Nanotechnology Initiative will support a new initiative to focus on applying the unique properties of materials that occur at the nanoscale to increase water availability, improve water delivery and use efficiency, and enable next-generation water-monitoring systems. Participating agencies include the Department of Energy, the Environmental Protection Agency, NASA, the National Institute of Standards and Technology, NSF and the Department of Agriculture.

•  A new video series to broaden awareness.
  • The series will build on the popular 2013Sustainability: Water episodes to explore how cutting-edge science and engineering research can transform how the country understands, designs and uses water resources and technologies. The videos will be produced by NBC Learn, the educational arm of NBCUniversal News Group, and will be shared in classrooms and with the public across a variety of platforms in the fall of 2016. The four-part series will promote public awareness of:
    • Water resources, the variability of these resources, and water infrastructure designs and needs.
    • Water conservation in rural and urban settings.
    • Water treatment, including purification and desalination techniques.
    • Water quality issues, including salinization and control.

• Innovative solutions from community college students at the nexus of food-water-energy.
  • NSF and the American Association of Community Colleges have chosen 10 finalists in the second annual Community College Innovation Challenge, which calls on students enrolled in community colleges to propose innovative science, technology, engineering and mathematics (STEM)-based solutions to perplexing, real-world problems.

Significant ongoing NSF investments:

• Engineering Research Centers for responsible water use.
  • The Engineering Research Center for Re-inventing the Nation’s Urban Water Infrastructure(ReNUWIt), a research partnership among University of California, Berkeley, Colorado School of Mines, New Mexico State University and Stanford University, is facilitating the improvement of the nation’s existing urban water systems through the development of innovative water technologies, management tools and systems-level analysis. This year, ReNUWIt will help advance urban water governance by releasing a set of decision-support tools that will allow utilities to quantify regional urban water resiliency and sustainability; promote the diversification of urban water supply portfolios by enabling virtual trading in regions with shared water resources; and support integrated management of water reuse and stormwater recharge systems.
  • The Nanosystems Engineering Research Center for Nanotechnology Enabled Water Treatment Systems(NEWT), led by Rice University in partnership with Arizona State University, the University of Texas at El Paso and Yale University, is enabling off-grid drinking water. The NEWT Nanosystems ERC is pursuing high-performance and easy-to-deploy water treatment systems that can turn both wastewater and seawater into clean drinking water. The modular treatment systems, which will need less energy and fewer chemicals, will safely enlist the selective properties of reusable engineered nanomaterials to provide clean water at any location or scale.

• Ongoing grants to study the food-energy-water nexus.
  • NSF has funded 17 grants, totaling $1.2 million, to support workshops on the interactions of food, energy and water, or FEW. Additionally, $6.4 million will supplement existing grants, enabling scientists to conduct additional research.
• Ongoing grants to study water sustainability and climate.
  • NSF and the U.S. Department of Agriculture’s National Institute for Food and Agriculture have made three sets of awards, the latest totaling $25 million, in the joint Water Sustainability and Climate program. The funding fosters research on how Earth’s water system is linked with climate change, land use and ecosystems.
• Special report on clean water technologies.
  • Beyond the White House, NSF-funded clean water-related research activities are happening now across the country. Engineers improve lives every day by imagining and creating innovative new technologies and tools. Today, NSF launches a new special report on future engineering solutions for clean water: NSF.gov/water.

Watch the White House Water Summit live atWhiteHouse.gov/live.

Join the conversation online with the hashtag#WHWaterSummit.

-NSF-

Program Contacts

JoAnn Slama Lighty, NSF, (703) 292-5382, jlighty@nsf.gov
Thomas Torgersen, NSF, (703) 292-8549, ttorgers@nsf.gov

Related Websites
Sustainability: Water: https://www.nbclearn.com/sustainability-water
NSF special report: Cleaner water, clearer future:http://www.nsf.gov/water
New grants foster research on food, energy and water: a linked system: http://www.nsf.gov/news/news_summ.jsp?cntn_id=135642
NSF and NIFA award $25 million in grants for study of water sustainability and climate:http://www.nsf.gov/news/news_summ.jsp?cntn_id=132501
On World Water Day, scientists peer into rivers to answer water availability questions:http://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=137901