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

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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


NASA Data Suggests the World is Running Out … of WATER

water 061715 california-gettyThe world’s largest underground aquifers – a source of fresh water for hundreds of millions of people — are being depleted at alarming rates, according to new NASA satellite data that provides the most detailed picture yet of vital water reserves hidden under the Earth’s surface.

Twenty-one of the world’s 37 largest aquifers — in locations from India and China to the United States and France — have passed their sustainability tipping points, meaning more water was removed than replaced during the decade-long study period, researchers announced Tuesday. Thirteen aquifers declined at rates that put them into the most troubled category. The researchers said this indicated a long-term problem that’s likely to worsen as reliance on aquifers grows.

Scientists had long suspected that humans were taxing the world’s underground water supply, but the NASA data was the first detailed assessment to demonstrate that major aquifers were indeed struggling to keep pace with demands from agriculture, growing populations, and industries such as mining.

Satellite system flags stressed aquifers

More than half of Earth’s 37 largest aquifers are being depleted, according to gravitational data from the GRACE satellite system.

“The situation is quite critical,” said Jay Famiglietti, senior water scientist at NASA’s Jet Propulsion Laboratory in California and principal investigator of the University of California Irvine-led studies.

Underground aquifers supply 35 percent of the water used by humans worldwide. Demand is even greater in times of drought. Rain-starved California is currently tapping aquifers for 60 percent of its water use as its rivers and above-ground reservoirs dry up, a steep increase from the usual 40 percent. Some expect water from aquifers will account for virtually every drop of the state’s fresh water supply by year end.

Read more: The countries facing the worst water shortages
Lake Mead’s water level has never been lower

The aquifers under the most stress are in poor, densely populated regions, such as northwest India, Pakistan and North Africa, where alternatives are limited and water shortages could quickly lead to instability.

The researchers used NASA’s GRACE satellites to take precise measurements of the world’s groundwater aquifers. The satellites detected subtle changes in the Earth’s gravitational pull, noting where the heavier weight of water exerted a greater pull on the orbiting spacecraft. Slight changes in aquifer water levels were charted over a decade, from 2003 to 2013.

“This has really been our first chance to see how these large reservoirs change over time,” said Gordon Grant, a research hydrologist at Oregon State University, who was not involved in the studies.

But the NASA satellites could not measure the total capacity of the aquifers. The size of these tucked-away water supplies remains something of a mystery. Still, the satellite data indicated that some aquifers may be much smaller than previously believed, and most estimates of aquifer reserves have “uncertainty ranges across orders of magnitude,” according to the research.

Aquifers can take thousands of years to fill up and only slowly recharge with water from snowmelt and rains. Now, as drilling for water has taken off across the globe, the hidden water reservoirs are being stressed.

“The water table is dropping all over the world,” Famiglietti said. “There’s not an infinite supply of water.”

The health of the world’s aquifers varied widely, mostly dependent on how they were used. In Australia, for example, the Canning Basin in the country’s western end had the third-highest rate of depletion in the world. But the Great Artesian Basin to the east was among the healthiest.

Before and after pictures show the extent of California's drought (Getty) Before and after pictures show the extent of California’s drought (Getty)
The difference, the studies found, is likely attributable to heavy gold and iron ore mining and oil and gas exploration near the Canning Basin. Those are water-intensive activities.

The world’s most stressed aquifer — defined as suffering rapid depletion with little or no sign of recharging — was the Arabian Aquifer, a water source used by more than 60 million people. That was followed by the Indus Basin in India and Pakistan, then the Murzuk-Djado Basin in Libya and Niger.

California’s Central Valley Aquifer was the most troubled in the United States. It is being drained to irrigate farm fields, where drought has led to an explosion in the number of water wells being drilled. California only last year passed its first extensive groundwater regulations. But the new law could take two decades to take full effect.

©The Washington Post

New Water Technologies & Approaches can help Californian’s Survive Drought

1-california-drought-farmsAnother year of crushing drought in California means new water cuts are in the works for both cities and farmers, who use up to 80 percent of the state’s water in an average year. In what is likely a sign of things to come, a group of farmers in the Sacramento-San Joaquin River Delta recently decided to voluntarily give up a quarter of their water by either fallowing the land or using other conservation methods.

Over the years, Silicon Valley—a region which has become synonymous with tech success—hasn’t been overly interested in funding water conservation technology, despite a drought taking place right in their backyard. Almost $12 billion was invested in Internet startups in 2014, compared to a few hundred million dollars in water startups.

But, it’s tech trends started in Silicon Valley— such as the Internet of things, big data, mobile, biotech and genetics, and nanotechnology —that could truly help farmers increase water efficiency. Founder and CEO of startup OnFarm, Lance Donny said a few years ago the agriculture industry was ripe for change and is “a sleeping giant” for digital tech.

It should be noted that farmers and cities mostly plan to reduce water use through new policies and better management, but here are some technologies I’ve been keeping an eye on that could help conserve more water in the state.

John Williamson harvests a four-acre field of oats on July 25, 2012 using a combine on his 200-acre organic farm in North Bennington, Vermont.
John Williamson harvests a four-acre field of oats on July 25, 2012 using a combine on his 200-acre organic farm in North Bennington, Vermont. (Robert Nickelsberg/Getty Images)

Sensor networks: Sensors and wireless networks are about as low cost as can be these days. Companies like Hortau, founded in 2002, use soil tension sensors—combined with data about temperature, weather and humidity—to manage smarter irrigation systems for farmers. These irrigation systems use gathered data to find more efficient times and better ways to use water.

Farm trade group American Farm Bureau Federation says 39 percent of farmers who grow water-needy corn or wheat now use sensor tech on their farms. Companies that already build sensor networks — like ThingWorx — for a variety of other industries are now targeting agriculture as new opportunities open up in the field.

While some companies are focused on making irrigation water go as far as possible, others are concentrating on protecting back-up water sources. Wisconsin-based startup Wellntel has developed a sensor system for monitoring ground water using sound waves, which farmers can then tap into like a savings account when surface water levels are low. It’s a far cry from the more traditional ground water measurement methods used today that rely on tape and chalk to monitor underground water.

Data analytics: Some farmers aren’t willing (or able) to pay for smart irrigation systems and instead rely on companies that can provide valuable analytics. For example, young startup PowWow Energy uses electricity data from basic smart meters that are installed on water pumps and networks to detect pump leaks. There’s no hardware to install and a farmer receives a text message if there’s an abnormal spike in water use (which corresponds with the spike in energy from the meter).

The Climate Corporation, which was founded in 2006 and acquired by Monsanto in 2013, is another company that is focused on helping farmers by analyzing massive amounts of data about environmental conditions. The firm delivers insight and recommendations to farmers based on the data, which can lead to water being used more efficiently.

 Jeff Hodel farms 6,000 acres of corn and soybeans near Roanoke, Ill.
Construction on a $1 billion seawater desalination plant in Carlsbad, California in January can be seen in this photo. (Mike Blake/Reuters)

Management software, social media: Basic software and social networking tools that are commonly used for communication in other industries are starting to be used widely in the agriculture industry and could lead to better conservation efforts.

The Farmer’s Business Network just raised $15 million from Google Ventures, Kleiner Perkins and DBL Investors to grow its social network for independent farmers. On the platform, farmers can compare and collaborate with others in the industry on issues including water use, irrigation tools and weather information to increase yield.

Last month, OnFarm launched a new update to its farm data management software, which included new tools for water management for drought-stricken farmers. The software helps farmers manage data like real-time soil moisture, water balance information, irrigation scheduling, water reporting and more.

A farmer sprays chemically engineered pesticides on a rice field in Leyte province, central Philippines. (Ted Aljibe/AFP via Getty Images)

Biotech and genetics: It’s not just digital tools that farmers are using to battle the drought. Companies are also using sophisticated genomics and breeding techniques to make seeds and crops that are more drought-resistant and water efficient.

Chicago-based Chromatin uses gene stacking (combining more than one gene in a plant) to make different types of water-efficient sorghum, which is a type of grass that is used for animal feed, grain, biofuel and brewing. Chromatin’s investors include GE Capital and BP Ventures.

Cibus is also using gene-editing technology to create water-efficient crops. The startup makes seeds that are pest tolerant and/or drought-resistant to increase a farmer’s harvest. Another company called Arcadia Biosciences went public in April and has helped seed companies deploy water-conservative crops like rice.


Construction continues on the Western Hemisphere's largest seawater desalination plant in Carlsbad
Construction on a $1 billion seawater desalination plant in Carlsbad, California in January can be seen in this photo. (Mike Blake/Reuters)

Water cleaning & reuse: Water purification and desalination (a process that removes salt and minerals from water) has been around for decades and is an oft-used tool in most arid countries around the world. Israel is a major proponent of the process and reuses about 80 percent of its municipal wastewater for irrigation.

Reverse osmosis is one the most popular processes used in water cleaning technology, but generally uses a lot of energy and ends up being quite expensive. A company called Desalitech, based in Newton, Massachusetts, hopes to change that by creating water systems that use significantly less energy and therefore become accessible to both independent and commercial farms.

Other types of next-gen water cleaning systems are leveraging the latest in nanotechnology to create processes that can clean water with less energy. A startup called NanoH20 has developed nanotech-tweaked filtration techniques that clean water faster and as a result was later bought by Korean giant LG last year for $200 million.

Test-tube burger
A lab-grown meat burger made from Cultured Beef, which has been developed by Professor Mark Post of Maastricht University in the Netherlands, is seen. (David Parry/AP Images)

Weirder ways for water conservation: There’s other, more unusual, methods startups are using to help reduce water use both directly and indirectly.

Five-year-old California startup mOasis makes a super absorbent gel polymer called hydrogel that farmers can put in soil ahead of planting seasons. The hydrogel — which is the size of a grain of sand, but can soak up 250 times its weight in water — absorbs excess water during irrigation and releases it as the soil dries out.

The company says using the gel can help farmers reduce water use by 20 percent, and cut water bills by 15 percent. The gel, developed at Stanford University, lasts about a year before it starts breaking down, and according to the company doesn’t leave behind bi-products that are environmentally questionable.

Permanently changing the paradigm of water-hungry industries could be another conceptual (and drastic) way to deliver water conservation in the long term. In California, cows raised for consumption often consume massive amounts of alfalfa, which is one of the most water-intensive crops. If cows raised explicitly for meat were replaced with lab-grown versions it would put less strain on water resources.

Startup Modern Meadow—based in Brooklyn, New York—is also hoping to change consumers’ eating habits by developing lab-printed meat that can be used in food or for leather goods. Another company called Cultured Beef is also working on their own version of lab-grown burgers as a way to conserve water.

California’s water issues aren’t expected to end anytime soon, but perhaps (just maybe) the ongoing drought will push Silicon Valley to finally do more.

World Economic Forum: Is Technology the Solution to Water Overuse?


***  Regular Readers/ Followers of ‘GTFSM’ might want to also do ‘Key Word Searches’ on our Blog for: Water Filtration, Waste-Water Remediation, Desalination, Soil-Water Measurement, Nano-Water, Nano-Filters ***

Despite limited availability of freshwater for human use (in the right form, at the right place and at the right time – availability estimated at a worldwide total of 4,200 cubic kilometres), withdrawals continue to increase globally (not in the US, I will come back to this with a later post) and will probably reach an estimated 5,000 cubic kilometres this year. In a situation of secular overuse, drought turns into a much more severe crisis.

By 2030, without a substantial improvement in water management, this figure could be close to 7,000 cubic kilometres – an increase driven by growth in population and prosperity. If we want to avoid a much more severe water crisis in future, we will have to find ways to reduce freshwater withdrawals by 40% compared to this status quo extrapolation.

A 40% reduction within the next 15 years seems like a lot, but it is not impossible. Inseveral posts here on LinkedIn, particularly those about the 2030 Water Resources Group that I am chairing, I pointed to ways that would significantly and cost-effectively contribute to narrowing the gap between withdrawals and sustainable supply of freshwater.

Measurement of withdrawals – the first step

Measurement would be an important first step: if you want to save water, you must measure its consumption in each sector of usage. If you can’t measure it, you can’t manage it.

In many if not most countries, we have to start in agriculture, which accounts for about 70% of all freshwater withdrawals worldwide, and more than 90% of water consumption (in California, according to US government data, it is 80% of all freshwater withdrawals).

But in too many instances, measurements of withdrawals remain incomplete, often with virtually no measurement of withdrawals by farmers (and often also a lack of measurement elsewhere, e.g. water withdrawals of municipal water supply schemes, to compare with delivery for estimates of leakage), and no measurement of actual needs – just rough global estimates, which indicate that withdrawals of freshwater by agriculture exceed the actual physiological need of plants by 100-150%. Fields are flooded, sprinklers run at noon, pumps continue when energy is free and the way out to the field is too long to bother about the water overuse; all entirely rational behaviours when water is not given any value at all.

Technologies to monitor and steer efficient use of water exist and function

Actually, the technologies to monitor, measure and steer efficient use of water exist – and they function. A good example are air and soil moisture sensors in a wireless network controlling drip irrigation I’ve seen being used in South Australia (my readers no doubt know many other comparable stories).

The first thing being measured is the humidity of the air, to adapt the water flow exactly to the evapotranspiration needs of the plant (or to stop the irrigation if the air is for some time too dry and most of it would not enter the soil). You will see these simplified weather stations all over the fields and vineyards.

Second, special devices in the soil measure how far down the irrigation water is actually seeping, i.e., as far down as the roots go, but not beyond. This optimises the water supply, and it protects the groundwater, since the irrigation water is ususally already supplemented with fertilisers.

At the heart of all this: no longer a nice farmhouse and barn we know from Europe and children’s books, but a computerised control centre, based on real-time data, which steers irrigation and the addition of fertilisers according to the exact need in different parts of the farm and different points in time.

Set incentives for comprehensive, cost effective solutions to water overuse

As an incentive to invest in such sophisticated schemes, and in order to make measurement and management fully relevant, water needs a value. Not surprisingly, in South Australia this is the case. Its value is set in a market of water usage rights tradable among farmers (i.e., giving a value does not mean imposing a tax on water use paid to government). And, as a result, it is carefully and smartly managed, contrary to many other places where it is seen, overused and abused as a free good.

Giving water a value will also work as a strong incentive for more water efficiency in industry, the generation of energy, and, last but not least, for reducing leakage losses in municipal water supply.

I know there are a number of innovations going even further; this is only the beginning of smart water management. An increasing number of companies offer highly innovative technologies and concepts; companies from the water sector (irrigation, treatment, supply, etc.) but also from other sectors (such as IBM, Dow and Ecolab for instance).

We need comprehensive, cost effective solutions to water overuse; piecemeal approaches and witch hunts will not do. Proper sensoring will be the first step.

Your comments, in particular with more information about innovations in measurement for better management of water, would be welcome.

This article is published in collaboration with LinkedIn. Publication does not imply endorsement of views by the World Economic Forum.

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Author: Peter Brabeck-Letmathe is the Chairman of the Board at Nestlé S.A.

Image: Tap water flows out of a faucet in New York June 14, 2009. WATER-BEVERAGES/ REUTERS/Eric Thayer.

by Peter Brabeck-Letmathe

Graphene and Water Treatment

1-graphene water-treatment-img_assist-400x300Water treatment is the collective name for a group of mainly industrial processes that make water more suitable for its application, which may be drinking, medical use, industrial use and more. A water treatment process is designed to remove or reduce existing water contaminants to the point where water reaches a level that is fit for use. Specific processes are tailored according to intended use – for example, treatment of greywater (from bath, dishwasher etc.) will require different measures than black water (from toilets) treatment.

Main types of water treatments

All water treatments involve the removal of solids (usually by filtration and sedimentation), bacteria, algae and inorganic compounds. Used water can be converted into environmentally acceptable water, or even drinking water through various treatments.

Water treatments roughly divide into industrial and domestic/municipal.

Industrial water treatments include boiler water treatment (removal or chemical modification of substances that are damaging to boilers), cooling water treatment (minimization of damage to industrial cooling towers) and wastewater treatment (both from industrial use and sewage).

1-graphene water-treatment-img_assist-400x300

Wastewater treatment is the process that removes most of the contaminants from wastewater or sewage, producing a liquid that can be disposed to the natural environment and a sludge (semi-solid waste). Wastewater is used water, and includes substances like food scraps, human waste, oils and chemicals. Home uses create wastewater in sinks, bathtubs, toilets and more, and industry donates its fare share as well. Wastewater and sewage need to be treated before being released to the environment. This is done in plants that reduce pollutants to a level nature can handle, usually through repeatedly separating solids and liquids, which progressively increases water purity.

Wastewater treatments usually consist of three levels: a primary (mechanical) level, in which solids are removed from raw sewage by screening and sedimentation. This level can remove about 50-60% of the solids, and is followed by the second level – secondary (biological) treatment. Here, dissolved organic matter that escaped primary treatment is removed, by microbes that consume it as food and convert it into carbon dioxide, water and energy. The tertiary treatment removes any impurities that are left, producing an effluent of almost drinking-water quality. The technology required for this stage is usually expensive and sophisticated, and demands a steady energy supply and specific chemicals. Disinfection, typically with chlorine, can sometimes be an additional step before discharge of the effluent. It is not always done due to the high price of chlorine, as well as concern over health effects of chlorine residuals.

Municipal water consists of surface water and groundwater. surface water, like lakes and rivers, usually require more more treatment than groundwater (water located under the ground). Municipal/community water is treated by public or private water utilities companies to ensure that the water is potable (safe for drinking), palatable (have no unusual or disturbing taste) and sufficient for the needs of the community.

Water flows or is pumped to a central treatment facility, where it is pumped into a distribution system. Initial screening is performed to remove large objects and then the water undergoes a series of processes like: pre-chlorination (for algae control), aeration (removal of dissolved iron and manganese), coagulation (removal of colloids), sedimentation (solids separation), desalination (removal of salt) and disinfection (killing bacteria). Other processes that may be used are: lime softening (the addition of lime to precipitate calcium and magnesium ions), activated carbon adsorption (to remove chemicals that cause taste and odor) and fluoridation (increasing the concentration of fluoride to prevent dental cavities).

As water is both vital for life and in limited supply, many efforts are placed to find technologies that can help ensure the maintainability of water resources. Among the innovative methods that have been researched and developed are:

  • nanotechnology – the use of nanotechnology to purify drinking water can help remove microbes and bacteria. Many nano-water treatment technologies use composite nanoparticles that emit silver ions to destroy contaminants.
  • membrane chemistry – membranes, through which water passes and is filtered and purified. The pores of membranes used in ultrafiltration can be remarkably fine. This technology exists, and efforts are constantly being made to make it more dependable, cost-efficient and common. Membranes’ selective separation grants filtration abilities that can pose as alternatives to processes like flocculation, adsorption and more.
  • seawater desalination – processes that extract salt from saline water, to produce fresh water suitable for drinking or irrigation. While this technology is in use and also holds much promise for growing in the future, it is still expensive, with reverse osmosis technology consuming a vast amount of energy (the desalination core process is based on reverse osmosis membrane technology).
  • Innovative wastewater processing – new technologies aim to transform wastewater into a resource for energy generation as well as drinking water. Modular hybrid activated sludge digesters, for example, can remove nutrients for use as fertilizers, decreasing almost by half the amount of energy traditionally required for this treatment in the process.

What is graphene?

Graphene is a two dimensional mesh of carbon atoms arranged in the form of a honeycomb lattice. It has earned the title “miracle material” thanks to a startlingly large collection of incredible attributes – this thin, one atom thick substance (it is so thin in fact, that you’ll need to stack around three million layers of it to make a 1mm thick sheet!) is the lightest, strongest, thinnest, best heat-and-electricity conducting material ever discovered, and the list does not end there. Graphene is the subject of relentless research and is thought to be able to revolutionize whole industries, as researchers work on many different kinds of graphene-based materials, each one with unique qualities and designation.

Graphene and water treatment

Water is an invaluable resource and the intelligent use and maintenance of water supplies is one of the most important and crucial challenges that stand before mankind. New technologies are constantly being sought to lower the cost and footprint of processes that make use of water resources, as potable water (as well as water for agriculture and industry) are always in desperate demand. Much research is focused on graphene for different water treatment uses, and nanotechnology also has great potential for elimination of bacteria and other contaminants.

Among graphene’s host of remarkable traits, its hydrophobia is probably one of the traits most useful for water treatment. Graphene naturally repels water, but when narrow pores are made in it, rapid water permeation is allowed. This sparked ideas regarding the use of graphene for water filtration and desalination, especially once the technology for making these micro-pores has been achieved. Graphene sheets (perforated with miniature holes) are studied as a method of water filtration, because they are able to let water molecules pass but block the passage of contaminants and substances. Graphene’s small weight and size can contribute to making a lightweight, energy-efficient and environmentally friendly generation of water filters and desalinators.

It has been discovered that thin membranes made from graphene oxide are impermeable to all gases and vapors, besides water, and further research revealed that an accurate mesh can be made to allow ultrafast separation of atomic species that are very similar in size – enabling super-efficient filtering. This opens the door to the possibility of using seawater as a drinking water resource, in a fast and relatively simple way.

Recent commercial activity in the field of graphene water treatments

In November 2014, the Malaysian based Graphene Nanochem that is traded in the AIM of the London Stock Exchange signed an agreement with Singapore-based HWV to develop and commercialize the PlatClean V1 system – a graphene-enhanced water treatment system for the oil and gas industry. In August 2014, the U.S based Biogenic Reagents announced starting a commercial production of graphene-carbon compound based Ultra-Adsorptive Carbon products to replace traditional activated carbon products for air and water purification.

In March 2013, Lockheed Martin announced the development of a new graphene-based water desalination technology, with hopes to commercialize it by 2014-2015. Their system is said to be energy-efficient and include graphene filters with nanoholes to screen salt from water.

Recent research activity in the field of graphene water treatments

In September 2013, researchers from China’s Nanjing University of Aeronautics announced graphyne, an allotrope of graphene, a promising material for water desalination that may even outperform graphene. Its high throughput and rejection of ions and pollutants give it a great potential for this purpose, and it will require lower energy use than traditional technologies. Also in September 2013, researchers from Korea suggested a new simple, high-yield method of synthesizing a new graphene-carbon nanotube-iron oxide (G-CNT-Fe) 3D functional nanostructures. The researchers report that these structures can function as excellent arsenic absorbents.

In May 2013, researchers from the University of El Paso (UTEP) developed a new water-recycling technology based on graphene membranes. The researchers won $100,000 in the University of Texas System Horizon Fund Student Investment Competition and formed a new company called American Water Recycling (AWR) to commercialize this technology. In April 2013, the UK government funded a $5m graphene membrane research at the University of Manchester. The aim of this research was to advance feasibility of desalination plants and other applications. In January 2013, researchers from Rice University and Lomonosov Moscow State University discovered that graphene oxide can quickly remove radioactive material from contaminated water, as it binds quickly to natural and human-made radionuclides and condenses them into solids. This can naturally be useful in contaminated sites cleanup and other applications.

In January 2012, MIT scientists showed (in simulations) that nanoporous graphene can filter salt water at a rate that is 2-3 orders of magnitude faster than current commercial desalination technologies, reverse osmosis (RO). This opens the door to smaller and more efficient desalination facilities.

Further reading

Fighting the Good Fight: Global Water Scarcity: The Nambian Beetle?

1-california-drought-farmsAccording to the World Water Management Institute, over one-third of the human population is affected by water scarcity. If nothing is done to prevent it, an estimated 1.8 billion people will be living in countries or regions with absolute water scarcity by 2025. Thankfully, due to bio-mimicry and advancements in physics, water filtration and desalination technologies have been growing and improving.

Graphene is a material possessing a very unique structure and properties, giving it a wide range of implications and uses, such as improved . Graphene is a one-atom thick sheet of carbon atoms. It is nearly transparent, very light, an excellent conductor of both heat and electricity, hydrophobic, and extremely strong. It is so strong that James Hone, professor of mechanical engineering at Columbia University, claims, “It would take an elephant, balanced on a pencil, to break through a sheet of graphene the thickness of Saran Wrap.”

But how can graphene be such a great if it is also hydrophobic? Single-atom-wide holes (called capillaries or defects) are made in the graphene sheet by bombarding it with gallium ions. This allows to be vigorously sucked through the holes in the material structure. Not everything can fit through these tiny holes and, like a sieve, whatever is too big will be filtered out.

University of Manchester researchers discovered that graphene is impermeable to all gases and vapors, except for water; even helium, the hardest gas to separate out, cannot pass through, along with any salts nine Angstroms or larger.

This process is most efficient when the water layer being filtered is only one atom thick (the same thickness as graphene), but filtration will still occur when the graphene is submerged in water. Due to graphene’s increased permeability – fifty times greater than that of conventional membranes – the filtration is ultrafast and has even been compared to the speed of an ordinary coffee filter. The University of Manchester team’s ultimate goal is to “make a filter device that allows a glass of drinkable water made from seawater after a few minutes of hand pumping.” A scientific advance like this would have game changing implications for water supply and policy around the world.

Due to its interesting properties, scientists have been trying to create and implement graphene more effectively since its discovery a few years ago. Columbia University engineering researchers have experimentally demonstrated for the first time that it is possible to electrically contact a two-dimensional material like graphene along its one-dimensional edge rather than contacting it from the top, which has been the conventional approach.

Through this approach, a new assembly technique has been developed that prevents contamination within layered materials (including layered graphene). Kenneth Shepard, Professor of Electrical Engineering at Columbia University, says that this “novel edge-contact geometry provides more efficient contact than the conventional geometry,” opening up possibilities in device applications and fundamental physics exploration.

So keep your eyes peeled; smart phones and other portable devices using “could potentially be commercially available within the next 5-10 years.” Graphene could also be used for more efficient and economically viable biofuel creation or lithium ion batteries found in electrically powered vehicles.

Scientists are also actively fighting water scarcity by taking inspiration from the creatures that handle it best. The Namibian Beetle (Stenocara gracilipes) is native to the southwest coast of Africa, one of the driest deserts in the world. The Namib Desert is known for its high temperatures, strong winds, and negligible rainfall, although it does experience fogs that move in from the Atlantic Ocean early in the morning and late at night.

The Namibian Beetle capitalizes on this windborne dew and gains an average of about twelve percent of its body weight through a technique known as fog-basking. When fog-basking, the beetle points its back at the oncoming breeze carrying the tiny dewdrops and waits. The back of the beetle is hydrophobic, but spotted with small hydrophilic bumps. When the dew-carrying breeze blows by, tiny water droplets are attracted to the hydrophilic bumps and condense, accumulating on the beetle’s back.

When the drops grow to a substantial size, the weight of the droplets and the force of the wind exceed the hydrophilic forces and the drops fall down the hydrophobic back, finally sliding into the beetle’s mouth. Products like fog nets have been enlisted to help solve human , but mimicking the beetle’s perfectly efficient biology can help scientists confront the water issue more effectively.

The challenge now is to create passive devices to collect water in desiccated environments for local consumption, particularly in poor countries. One example of a bio-mimicry product that seems to take inspiration from the Namibian Beetle is the Dew Bank Bottle. More bio-mimicry in the future, in many scientific fields, could help scientists discover more efficient, natural ways of solving some of our greatest issues.

Advances in physical understanding, its applications, and the study of our environment and bio-mimicry help us develop more effective ways to fight freshwater scarcity around the world. Graphene has proven to be an incredible material with a vast range of unique, useful properties, but taking a step outside the lab to examine how life naturally overcomes different problems can be just as informative. Hopefully, humble creatures like the Namibian Beetle will help usher in a day when the lack of is no longer an issue. In the words of Dr. Irina Grigorieva, “We are not there yet but this is no longer science fiction.”

Fighting the global water scarcity issue
Fog coming in from the Atlantic Ocean, near Sossusvlei, Namib desert. Credit: Moongateclimber

Water Purification at the Molecular Level: Research at Tufts University

1-water nano water-filter2Fracking for oil and gas is a dirty business. The process uses millions of gallons of water laced with chemicals and sand. Most of the contaminated water is trucked to treatment plants to be cleaned, which is costly and potentially environmentally hazardous.

A Tufts engineer is researching how to create membranes for filters that may one day be able to purify the water right at a fracking site. Ayse Asatekin, an assistant professor of chemical and biological engineering, is designing materials for sophisticated filters that would be more cost-effective and use less energy than current methods. They would work not only at fracking sites, but could also be used to clean industrial waste from manufacturing and pharmaceutical companies and to provide clean drinking water.

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Ayse Asatekin is experimenting with polymers that could one day be used in filters to distinguish between different chemicals. Photo: Kelvin Ma

Using filters to purify water isn’t new. Hippocrates, in the fourth century B.C., invented a bag filter to trap sediments that caused water to smell and taste bad, while Sanskrit writings from 2000 B.C. describe sand and gravel filtration. Water is still filtered using the same basic principle: force it through a porous membrane that traps large particles while allowing clean water to pass through.

But to catch certain chemicals, you need a membrane with pores that measure just one nanometer across. For perspective, a strand of human hair is some 60,000 nanometers wide.

For this nanotechnology, Asatekin has turned to polymers—molecules strung together to form long chains. “A polymer is like a necklace of beads,” Asatekin says. “You can make a long chain or a short chain; you can make branches going off it. By playing with all these things, you can control a polymer’s configuration and its properties.”

Ayse Asatekin holds a sample of a water filtration membrane in her lab. Photo: Kelvin Ma >>>

She’s using the polymer chains to create a grid of ultra-small pores capable of snaring the tiniest pollutants. These nano-membranes are working in the lab, and will soon be ready to be designed for specific uses, manufactured and tested in the field.

But someday, in addition to being small, Asatekin’s polymer filters will also be smart: she’s experimenting with polymers that could distinguish between different chemicals. “So even if two molecules were the same size, the polymer would ‘know’ that one has certain functional groups that the other lacks, and be able to block it,” she says.

Right now she is testing polymers that can recognize the difference between molecules using characteristics that define their structures. This could allow, for example, a smart membrane to separate a pharmaceutical from the chemical compounds that catalyze the reactions to create the drug.2-water nano nano1

Filters Go Mobile

Asatekin’s inspiration for the polymers came from observing bacteria. All bacterial cell walls, cell membranes and membranes that separate the nuclei from the cytoplasm have structures that allow one type of molecule to pass through their “doorways” while blocking others, she says.

“For example, there is one structure that allows a sugar to come in, one that allows calcium ions but no other molecules,” she says. “Each cell’s wall or membrane structure has its own target, and is very selective—this is what I am hoping my polymers will be able to do maybe 10 to 15 years from now.”

A polymer membrane looks like a piece of slightly shiny paper. To create a membrane, Asatekin takes her polymers and paints them onto a large-pore, paper-like material that is itself an acrylic polymer specially manufactured to suit each project. They might not look exciting, but it is these membranes that will allow filtration to go mobile.

For the membranes to be turned into actual transportable units to be used in the field at fracking, manufacturing or other sites, a company would need to scale up their production to make them as wide, long sheets. Then, several flat membranes would be rolled into large cylinders that could be one inch in diameter by one foot long or as large as eight inches in diameter by 40 inches tall, depending on the use. These pipe-like structures would be attached to a pump and secured on a rig, sometimes singly and sometimes stacked, and pressurized water would be forced through them, coming out clean on the other side.

Whether they are used for pharmaceutical purification, cleaning industrial wastewater or producing drinking water, the membranes Asatekin’s group is designing could be cleaned and last longer than current filters. More field testing is needed to define exactly how these systems would function. At fracking or industrial sites, the filtering process eliminates the need to transport contaminated water to a treatment facility. The purified water could be reused without ever leaving the site.

And the membranes’ mobility means they could purify water in remote areas of the world, a boon for the estimated 780 million people with no access to clean water, according to the World Health Organization and UNICEF’s Joint Monitoring Programme.

The nano-membranes would also save energy by eliminating the need boil water to turn it into vapor and then distill it.

“The Department of Energy estimates that these industrial purification and separation processes account for 40 to 70 percent of energy costs generated by a chemical manufacturing process,” Asatekin says. “What we are working on is expanding the applications for polymer membranes that would improve the energy efficiency of many manufacturing processes by not having to use distillation, but instead, passing it through our selective filters.”

Asatekin’s polymer membranes have another quality important for industrial use—something called fouling resistance. This means that oil and other heavy substances can’t clog the membrane pores and foul the purification process. Clean Membranes, the Tyngsboro, Massachusetts, company that Asatekin co-founded and now consults for, is working with oil and gas companies across the country to develop polymer membrane applications tailored to their needs.

Source: Tufts University

Nanotechnology: Can New Discoveries Help Us Provide Clean Water and Clean Renewable Energy?

1-BC Water safe_image“Great Things from Small Things”

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Nanotechnology and Our Future

Nanotechnology has been called “The Next Industrial Revolution.” It will or already has, impacted almost every facet of our daily lives. From ‘Nano-Enabled’ Solar Energy & Storage, Nano-Enabled Water Filtraion & Remediation to ‘Nano-Enabled’ Drug Therapies for Cancer, Alzheimers and DiabetesNanotechnology will serve to advance our technology capabilities to meet the Vision for a Better Quality of Life for all of us who share this Planet Earth as ‘Home’.

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Genesis Nanotechnology (GNT™) is an applied Nanotechnology Development Company. GNT™ acquires University developed ‘Nano-IP’ (Intellecutual Properties or Technologies), then develops; Patents, Trade Secrets & Processes for the commercialization of those technologies.

Our areas of focus (our passions) are Clean, Renewable Energy and Clean, Accessible Water via ‘Nanotechnology’ – for our Planet – Our Home.

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With the installation of this first article (from the Financial Times) we will begin a series of articles addressing not only California’s “Water Disaster”, but the impact the lack of access to Clean, Abundant, Affordable WATER is having on our world – PLANET EARTH.

More importantly, we will address how we believe Nanotechnology with its many ‘cross disciplines’ across many Scientific Fields “holds the KEY” to solving the World’s Water Crisis. We believe that Nanotechnology and the need for water will also create commercial opportunities and the “Opportunity to Do Well … by Doing Good”.Team GNT

1-World Water Scarcityfig1Next Week: “Nanotechnology and Desalinization – “An Answer to World’s Thirst for Water?”

Read Our First Installment of “Water – The New Blue Gold” Here:

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Our Foundational Technologies are in Water Filtration (including desalinaiztion), Waste Water Remediation (including remediation of ‘Fracking Water’) and Mass Synthesis (production) of Nanomaterials that will enable new or replace existing technologies across a broad spectrum of mature Industries (Ex. – Textiles, Paints, Coatings, Inks, Solar, Electronics, Sensors, Water Filtration).

GNT™ incorporates all applicable Tax Incentives, Tax Credits, Research Grants & Supports provided by the U.S. and Canadian governments, into our Funding Model.

Our GNT Team plans for the transition of “Developed Technology” into “Commercial Entities” even as we continue to work closely with our University Partners. While there are many ‘off ramps’ (‘Exit Strategies’) for the developed technologies, most will have a 3 to 5 Year Time Horizon, at which time our experience tells us that our ‘Investment Multiple’ ranges from 80:1 to 100:1. – “Doing Well … by Doing Good!”

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Water Wars: California’s Epic Draught Has Created A New ‘Blue Gold Rush’


*** Note to Readers: With the installation of this first article (from the Financial Times) we will begin a series of articles addressing not only California’s “Water Disaster”, but the impact the lack of access to Clean, Abundant, Affordable WATER is having on our world – PLANET EARTH.

More importantly, we will address how we believe Nanotechnology with its ‘cross disciplines’ across many Scientific Fields “holds the KEY” to solving the World’s Water Crisis. We believe that Nanotechnology and the need for water will also create commercial opportunities and the “Opportunity to Do Well … by Doing Good”.  –  Team GNT 1-World Water Scarcityfig1

Next Week: “Nanotechnology and Desalinization – “An Answer to World’s Thirst for Water?”

(Story from the Financial Times: By Pilita Clark)

With his military fatigues and the holstered gun at his hip, Lieutenant John Nores Jr. is a slightly unnerving sight as he slips through the woody foothills overlooking the southern edge of California’s Silicon Valley. But what the 45-year-old game warden has come to look at is more alarming.

Here in the late summer heat, not far from the sleek headquarters of technology giants Apple and Google, he leads the way to a carefully hidden patch of terraced ground pockmarked with hundreds of shallow holes that until very recently contained towering marijuana plants.

1-CA MJ aeecf23a-5943-11e4-9546-00144feab7deThere were about 2,000 plants here,” says Lt Nores as he explains how he and his colleagues from California’s fish and wildlife department recently launched an early morning raid on the plantation, ripping out a crop worth about $6m to the Mexican drug cartel that grew it”

In deep trouble

California pioneered laws allowing marijuana use for medical reasons. But it has yet to follow states such as Colorado that permit recreational use and, in any case, this crop was on public land, making it illegal and dangerous to eliminate – Lt. Nores has witnessed several shoot-outs over the past decade.

He estimates that each of the state’s 2,000-odd cartel pot farms contains an average of 5,000 plants, and that each one sucks up between eight and 11 gallons of water a day, depending on the time of year. That means at least 80m gallons of water – enough for more than 120 Olympic-size swimming pools – is probably being stolen daily in a state that in some parts is running dry as a three-year-old drought shrinks reservoirs, leaves fields fallow and dries wells to the point that some 1,300 people have had no tap water in their homes for months.

Jerry Brown, California’s governor, declared a state of emergency in January after the driest year on record in 2013, but as the annual wet season beckons, the prospect of a complete drought recovery this winter is highly unlikely, government officials say.

“Marijuana cultivation is the biggest drought-related crime we’re facing right now,” says Lt Nores as he pokes at a heap of plastic piping the growers used to divert water from a dried-up creek near the plantation.

But California’s drought is exposing a series of problems in the US’s most populous state that are a reminder of an adage popularized by Michael Kinsley, the columnist: the scandal is often not what is illegal but what is legal.

Growing competition

The theft of 80m gallons of water a day by heavily armed marijuana cartels is undoubtedly a serious concern, not least when the entire state is affected by drought and 58 per cent is categorized as being in “exceptional drought”, as defined by the government-funded US Drought Monitor.

However, this is a tiny fraction of the water used legally every day in a state that, like so many other parts of the world, has a swelling population driving rising competition for more heavily regulated supplies that have long been taken for granted and may face added risks as the climate changes.

California has always been a dry state. For almost six months of the year many of its citizens get little rain. There have been at least nine statewide droughts since 1900, not counting the latest one.

The state’s history is littered with water wars, among them the conflicts surrounding Los Angeles’s move to siphon off most of the Owens river last century that inspired the classic 1974 film, Chinatown . That dispute was over just one part of a vast system of canals and reservoirs built in the last 100-odd years that are the reason California is sometimes called the most hydro-logically altered landmass on the planet.

The system channels water from wetter to drier spots, using rivers and streams that in a normal year fill with melted snow from mountain ranges ringing the state, supplying about a third of California’s farms and cities.

1-CA short_of_water_caThe crisis is more severe because a decline in snowfall has compounded problems caused by the lack of rain. The state’s mountain snowpack was just 18 per cent of its average earlier this year, a situation scientists say could be repeated as the climate warms.

As a result eight major reservoirs were last week holding less than half their average storage for this time of year. Reservoir levels sank worryingly when a bad drought hit California in 1976-77, but there were fewer than 22m people in the state then, compared with 38.3m now.

There were also fewer laws such as those protecting creatures such as the endangered Delta smelt, a finger-sized fish that can be affected by the management of the canal system, prompting restrictions on pumping the water used by a farming sector that accounts for nearly 80 per cent of the state’s human water use. Those laws regularly inflame debate between conservationists and farmers during droughts – and are doing so again today.

The farmer’s story

“I farm in a very environmentally conscious manner, but these regulations have made it much worse for the farmers,” says Barat Bisabri, a citrus and almond farmer whose property lies in the Central Valley, one of the regions worst hit by the drought.

This flat, fertile strip runs south for about 450 miles from the northern reaches of the Sacramento Valley through the heart of the state and grows a lot of what America eats. Nearly half the fruit and nuts grown in the US come from California, including 80 per cent of the world’s almonds.

An investigation into how businesses are having to adapt to rising water costs around the world

Much of that produce comes from the Central Valley, where farming is carried out on an industrial scale. Crops and orchards grow up to the edge of people’s houses. Driving down the valley’s long, straight roads, it is striking to see an orchard of dead, brown trees next to another with puddles of water around healthy ones.

This may partly be a symptom of a century-old water rights system that critics say is so weak and archaic it makes it hard for regulators to tell whose supplies should be cut during a drought.

Mr. Bisabri’s grim predicament shows why one study estimates the drought will cost the state $2.2bn in 2014.

From the windows of the roomy farmhouse that overlooks row upon row of the property’s citrus trees, Mr Bisabri points to two of California’s main waterways, the Delta-Mendota Canal and the California Aqueduct. Both run straight through his farm but because of the drought, authorities have sharply limited the amount of water many users can take from them.

“Unfortunately we cannot get water from either of them this year,” says Mr Bisabri, as he explains how, a few weeks earlier, he used bulldozers to rip out 85 acres of healthy mandarin, orange and grapefruit trees that would have used so much water it would have made the rest of the crop far less valuable.

“I had to make a decision to kill some so the other ones could survive,” he says, as he drives to the bare patch where the trees once stood. “Had I not made that decision and kept all the citrus that we had, then I would have run out of water in the middle of August.” It is a dilemma facing farmers across the Central Valley, many of whom have shifted from crops such as tomatoes or peppers to more valuable almonds or other trees that cannot be left unwatered in a dry year.

Perennial crops such as nuts and grapes accounted for 32 per cent of the state’s irrigated crop acreage in 2010, up from 27 per cent in 1998. The shift has been even more marked in the southern Central Valley, so when drought hits, farmers face difficult choices.

A few miles down the road from his farm, Mr Bisabri stops at a jaw-dropping sight by an almond orchard of withered trees: a huge earthmoving machine is scooping up several at a time and feeding them into another machine that grinds them with an ear-splitting roar into great mounds of woodchip.

“That is exactly the same machine that we used on my farm,” he says.

Mr Bisabri has had to bring in water from other sources this year, but he says the price was almost $1.2m, 10 times what it was the previous year.

That does not include the $250,000 he spent on digging new wells to try to get supplies from the one source farmers and communities have always turned to in times of drought: groundwater.

In a normal year, aquifers supply about a third of the state’s water. In a drought, that can rise to as much as 60 per cent. But one of the most alarming aspects of this drought is that groundwater levels are plummeting.

“Water levels are dropping at an incredibly rapid rate in some places, like 100ft a year,” says Michelle Sneed, a hydrologist with the US Geological Survey who monitors groundwater in the Central Valley. “It is very extreme. Ordinarily, talking with hydrologists, if you would talk about a well dropping 10ft a year that would really get somebody’s attention, like wow! Really? Ten feet? And now we’re 10 times that.”

The depletion of this vital resource is not just a concern because it is so difficult to refill some aquifers when drought eventually subsides. It is also creating extraordinary rates of subsidence because as the groundwater disappears the land above it can sink. In one part of the valley, land has been subsiding by almost a foot a year, which Ms Sneed says is among the fastest rates anywhere in the world.

This is damaging the very canal system California built to reduce reliance on groundwater, she says, because these waterways depend on gravity for a steady flow and when parts of a canal start sinking it creates a depression that needs more water to fill it before flows can resume.

‘We ran out of water in June’

Two hours’ drive south from Mr. Bisabri’s farm, the town of East Porterville has more pressing groundwater worries. At least 1,300 people in the town rely for drinking and bathing water on wells that have gone dry as the drought has deepened.

“We ran out of water in June,” says Donna Johnson, a 72-year-old retired counsellor who delivers water to dozens of dry households from the back of her pick-up truck. Ms Johnson depends on a hose running to her home from a neighbor whose well is still working.

Until now, California has been notable among dry, western states for a pump-as-you-please approach to groundwater. A powerful agricultural lobby resisted repeated attempts at reform.

But the severity of this drought finally led to a package of measures signed into law in September requiring local agencies to monitor and manage wells, or face state intervention. Some critics say it is too little too late: many local agencies will have five to seven years to come up with plans, and until 2040 to implement them. Still, it is a lot better than nothing, say others.

“It’s a giant step for California,” says Robert Glennon, a law professor at the University of Arizona and the author of Unquenchable: America’s Water Crisis and What To Do About It . “You cannot manage what you don’t measure, full stop.”

The crisis may also encourage approval of another measure to be voted on in November allowing billions of dollars to be borrowed for new reservoirs and other steps to strengthen drought resilience.

None of this will help farmers such as Mr. Bisabri or the residents of East Porterville this year. Still, it is one more example of how the state often responds to a serious drought, says Jay Lund, a water expert at the University of California, Davis.

“Every drought brings a new innovation where we say, ‘Oh, here’s something we haven’t been doing that would really be helpful’,” says Prof Lund, pointing to irrigation systems, reservoirs and water markets rolled out after past dry spells.

“In this drought, it’s groundwater regulation so far,” he says. And will it eventually work? “It opens the door.”

That is small comfort when the latest outlook from the US Climate Prediction Center suggests the drought “will likely persist or intensify in large parts of the state” this winter.

1-World water-shortage“If there’s no water for people to live, and you don’t have the basic necessities of life, your population is going to leave,” says Andrew Lockman, the emergency services manager responsible for East Porterville. “Our primary economic driver is agriculture. If there’s no water to water crops, we’re not going to have any agriculture business, so you could see the economy of this area just decimated.”

Next Week: “Nanotechnology and Desalinization – “An Answer to World’s Thirst for Water?”

1-World Water Scarcityfig1

Gold-palladium nanocatalysts set new mark for breakdown of nitrites

Ordered QDs(Nanowerk News) Chemical engineers at Rice University have found a new catalyst that can rapidly break down nitrites, a common and harmful contaminant in drinking water that often results from overuse of agricultural fertilizers.
Nitrites and their more abundant cousins, nitrates, are inorganic compounds that are often found in both groundwater and surface water. The compounds are a health hazard, and the Environmental Protection Agency places strict limits on the amount of nitrates and nitrites in drinking water. While it’s possible to remove nitrates and nitrites from water with filters and resins, the process can be prohibitively expensive.
gold and palladium nanoparticles can rapidly break down nitrites
Researchers at Rice University’s Catalysis and Nanomaterials Laboratory have found that gold and palladium nanoparticles can rapidly break down nitrites.
“This is a big problem, particularly for agricultural communities, and there aren’t really any good options for dealing with it,” said Michael Wong, professor of chemical and biomolecular engineering at Rice and the lead researcher on the new study. “Our group has studied engineered gold and palladium nanocatalysts for several years. We’ve tested these against chlorinated solvents for almost a decade, and in looking for other potential uses for these we stumbled onto some studies about palladium catalysts being used to treat nitrates and nitrites; so we decided to do a comparison.”
Catalysts are the matchmakers of the molecular world: They cause other compounds to react with one another, often by bringing them into close proximity, but the catalysts are not consumed by the reaction.
In a new paper in the journal Nanoscale (“Supporting palladium metal on gold nanoparticles improves its catalysis for nitrite reduction “), Wong’s team showed that engineered nanoparticles of gold and palladium were several times more efficient at breaking down nitrites than any previously studied catalysts. The particles, which were invented at Wong’s Catalysis and Nanomaterials Laboratory, consist of a solid gold core that’s partially covered with palladium.
Over the past decade, Wong’s team has found these gold-palladium composites have faster reaction times for breaking down chlorinated pollutants than do any other known catalysts. He said the same proved true for nitrites, for reasons that are still unknown.
“There’s no chlorine in these compounds, so the chemistry is completely different,” Wong said. “It’s not yet clear how the gold and palladium work together to boost the reaction time in nitrites and why reaction efficiency spiked when the nanoparticles had about 80 percent palladium coverage. We have several hypotheses we are testing out now. “
He said that gold-palladium nanocatalysts with the optimal formulation were about 15 times more efficient at breaking down nitrites than were pure palladium nanocatalysts, and about 7 1/2 times more efficient than catalysts made of palladium and aluminum oxide.
Wong said he can envision using the gold-palladium catalysts in a small filtration unit that could be attached to a water tap, but only if the team finds a similarly efficient catalyst for breaking down nitrates, which are even more abundant pollutants than nitrites.
“Nitrites form wherever you have nitrates, which are really the root of the problem,” Wong said. “We’re actively studying a number of candidates for degrading nitrates now, and we have some positive leads.”
Source: Rice University

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