Category Archives: water

Using only sunlight to desalinate water

The researchers seem to believe that this new desalination technique could be a game changer. From a June 20, 2017 news item on Azonano,

An off-grid technology using only the energy from sunlight to transform salt water into fresh drinking water has been developed as an outcome of the effort from a federally funded research.

The desalination system uses a combination of light-harvesting nanophotonics and membrane distillation technology and is considered to be the first major innovation from the Center for Nanotechnology Enabled Water Treatment (NEWT), which is a multi-institutional engineering research center located at Rice University.

NEWT’s “nanophotonics-enabled solar membrane distillation” technology (NESMD) integrates tried-and-true water treatment methods with cutting-edge nanotechnology capable of transforming sunlight to heat. …

A June 19, 2017 Rice University news release, which originated the news item, expands on the theme,

More than 18,000 desalination plants operate in 150 countries, but NEWT’s desalination technology is unlike any other used today.

“Direct solar desalination could be a game changer for some of the estimated 1 billion people who lack access to clean drinking water,” said Rice scientist and water treatment expert Qilin Li, a corresponding author on the study. “This off-grid technology is capable of providing sufficient clean water for family use in a compact footprint, and it can be scaled up to provide water for larger communities.”

The oldest method for making freshwater from salt water is distillation. Salt water is boiled, and the steam is captured and run through a condensing coil. Distillation has been used for centuries, but it requires complex infrastructure and is energy inefficient due to the amount of heat required to boil water and produce steam. More than half the cost of operating a water distillation plant is for energy.

An emerging technology for desalination is membrane distillation, where hot salt water is flowed across one side of a porous membrane and cold freshwater is flowed across the other. Water vapor is naturally drawn through the membrane from the hot to the cold side, and because the seawater need not be boiled, the energy requirements are less than they would be for traditional distillation. However, the energy costs are still significant because heat is continuously lost from the hot side of the membrane to the cold.

“Unlike traditional membrane distillation, NESMD benefits from increasing efficiency with scale,” said Rice’s Naomi Halas, a corresponding author on the paper and the leader of NEWT’s nanophotonics research efforts. “It requires minimal pumping energy for optimal distillate conversion, and there are a number of ways we can further optimize the technology to make it more productive and efficient.”

NEWT’s new technology builds upon research in Halas’ lab to create engineered nanoparticles that harvest as much as 80 percent of sunlight to generate steam. By adding low-cost, commercially available nanoparticles to a porous membrane, NEWT has essentially turned the membrane itself into a one-sided heating element that alone heats the water to drive membrane distillation.

“The integration of photothermal heating capabilities within a water purification membrane for direct, solar-driven desalination opens new opportunities in water purification,” said Yale University ‘s Menachem “Meny” Elimelech, a co-author of the new study and NEWT’s lead researcher for membrane processes.

In the PNAS study, researchers offered proof-of-concept results based on tests with an NESMD chamber about the size of three postage stamps and just a few millimeters thick. The distillation membrane in the chamber contained a specially designed top layer of carbon black nanoparticles infused into a porous polymer. The light-capturing nanoparticles heated the entire surface of the membrane when exposed to sunlight. A thin half-millimeter-thick layer of salt water flowed atop the carbon-black layer, and a cool freshwater stream flowed below.

Li, the leader of NEWT’s advanced treatment test beds at Rice, said the water production rate increased greatly by concentrating the sunlight. “The intensity got up 17.5 kilowatts per meter squared when a lens was used to concentrate sunlight by 25 times, and the water production increased to about 6 liters per meter squared per hour.”

Li said NEWT’s research team has already made a much larger system that contains a panel that is about 70 centimeters by 25 centimeters. Ultimately, she said, NEWT hopes to produce a modular system where users could order as many panels as they needed based on their daily water demands.

“You could assemble these together, just as you would the panels in a solar farm,” she said. “Depending on the water production rate you need, you could calculate how much membrane area you would need. For example, if you need 20 liters per hour, and the panels produce 6 liters per hour per square meter, you would order a little over 3 square meters of panels.”

Established by the National Science Foundation in 2015, NEWT aims to develop compact, mobile, off-grid water-treatment systems that can provide clean water to millions of people who lack it and make U.S. energy production more sustainable and cost-effective. NEWT, which is expected to leverage more than $40 million in federal and industrial support over the next decade, is the first NSF Engineering Research Center (ERC) in Houston and only the third in Texas since NSF began the ERC program in 1985. NEWT focuses on applications for humanitarian emergency response, rural water systems and wastewater treatment and reuse at remote sites, including both onshore and offshore drilling platforms for oil and gas exploration.

There is a video but it is focused on the NEWT center rather than any specific water technologies,

For anyone interested in the technology, here’s a link to and a citation for the researchers’ paper,

Nanophotonics-enabled solar membrane distillation for off-grid water purification by Pratiksha D. Dongare, Alessandro Alabastri, Seth Pedersen, Katherine R. Zodrow, Nathaniel J. Hogan, Oara Neumann, Jinjian Wu, Tianxiao Wang, Akshay Deshmukh,f, Menachem Elimelech, Qilin Li, Peter Nordlander, and Naomi J. Halas. PNAS {Proceedings of the National Academy of Sciences] doi: 10.1073/pnas.1701835114 June 19, 2017

This paper appears to be open access.

Sustainable water desalination with self-cleaning membranes

This desalination technology comes from the United Arab Emirates (UAE). from an April 13, 2017 news item on Nanowerk,

An advanced water treatment membrane made of electrically conductive nanofibers developed at Masdar Institute was highlighted by Dr. Raed Hashaikeh, Professor of Mechanical and Materials Engineering at Masdar Institute, in his keynote speech during the 3rd International Conference on Desalination using Membrane Technology held last week in Spain.

An April 13, 2017 Masdar Institute press release by Erica Solomon, which originated the news item, expands on the theme,

Self-cleaning membranes offer a critically needed solution to the problem of fouling, which is the unwanted build-up of organic and inorganic deposits on a membrane’s surface that reduces the membrane’s ability to filter impurities. Water treatment and purification membranes that can easily clean themselves when fouled could make pressure-driven membrane filtration systems used to treat and desalinate water more energy-efficient.

“Keeping membranes clean, permeable and functional is a great challenge to membrane desalination technologies. When a membrane becomes fouled, its pores get blocked and its flux is severely reduced, which means that much less water can pass through the membrane at a constant pressure,” Dr. Hashaikeh explained.

Conventional methods for cleaning fouled membranes involve expensive and harsh chemical treatments, and often lead to water treatment plant shut-downs, which can cost millions of dollars in lost operational hours. In the UAE, annual spending on desalination is already estimated to cost AED12 billion, indicating a pressing need for solutions that avoid costly shut-downs and treatments.

In addition to posing a heavy financial burden, fouled membranes are also a sustainability issue, as once a membrane becomes fouled, the higher pressure needed to push water through clogged pores significantly increases the plant’s energy consumption. The harsh chemicals used to clean a fouled membrane are also bad for the environment and require neutralizing. Thus, finding a way to easily and quickly clean fouled membranes not only makes financial sense, but environmental sense.

In a country like the UAE, where natural gas-powered thermal desalination produces over 80% of the country’s domestic water, innovative technologies like self-cleaning membranes to support a shift toward lower-energy and lower-cost membrane-based desalination are essential for achieving economic and environmental balance while meeting the UAE’s water demands.

And now, Dr. Hashaikeh’s research group may have brought the UAE closer towards realizing a more sustainable and economic approach to membrane desalination through their research on the application of advanced nanofibers for enhanced, self-cleaning membranes.

The group has leveraged the electrically conductive nature of a special kind of nanofiber, called carbon nanotubes (CNT). CNTs are tiny cylindrical tubes made of tightly bonded carbon atoms, measuring just one atom thick. But the CNTs Dr. Hashaikeh’s team used, which were provided by global security, aerospace, and information technology company Lockheed Martin, are not ordinary CNTs.

“The carbon nanostructures supplied by Lockheed Martin are special; they are networked. This means that they are composed of many interconnecting channels that branch off in all directions. This interconnectivity is what enables the entire membrane to become completely cleaned when electricity is applied to it,” Dr. Hashaikeh said.

The networked CNTs, also known as carbon nanostructures (CNS), coupled with the team’s expert membrane fabrication know-how, resulted in the development of two different types of membranes that can clean themselves when a low-voltage electric current is run through them.

The first type is a microfiltration membrane, which has pores sizes ranging from 100 nanometers to 10 micrometers, where a nanometer is approximately one hundred thousand times smaller than the width of a human hair and a micrometer one thousand times larger than a nanometer. The second is a nanofiltration membrane with pore sizes ranging from one to ten nanometers. Both membranes demonstrated the ability to clean themselves in response to an electric shock, which resulted in the immediate restoration of the membranes’ flux.

Dr. Hashaikeh’s investigation of a self-cleaning membrane began four years ago, when he realized that electrolytic cleaning – which is the process of removing soil, scale or corrosion from a metal’s surface by subjecting it to an electric current – could also be used to clean membranes. To prove his theory, he coated a membrane with ordinary CNTs. When a voltage was applied to the membrane, the parts of the membranes that were coated with CNTs were successfully cleaned. Dr. Hashaikeh filed a patent for this in-situ electrolytic cleaning process with the United States Patent and Trademark Office (USPTO) in 2014.

However, there were limitations to this discovery, namely that only specific areas in the coated CNTs were cleaned, not the entire membrane. Thus, to develop an efficient, self-cleaning membrane with commercial potential, Dr. Hashaikeh required a material that would easily allow electric shockwaves to penetrate through the entire membrane’s surface area.

The unique, interconnected structure of Lockheed Martin’s carbon nanostructures proved to be just the right type of electrically conductive, nano-fibrous material required.

“We immediately recognized that Lockheed Martin’s CNTs might enable electricity to pass through the entire surface, but we had to modify the nanostructures to transform the material into a membrane. To do this, we controlled certain properties, such as wettability and pore size, and improved its mechanical strength by incorporating polymer materials,” he explained.

Dr. Haishaikeh’s team successfully developed a self-cleaning microfiltration membrane in 2014 and a paper describing the research was published in the Journal of Membrane Science. But they did not stop there; they wanted to take their research a step further and find a way to develop a self-cleaning nanofiltration membrane. While microfiltration membranes are useful for removing larger particles, including sand, silt, clays, algae and some forms of bacteria, nanofiltration membranes can go a step further, removing most organic molecules, nearly all viruses, most of the natural organic matter and a range of salts. Nanofiltration membranes also remove divalent ions, which make water hard, making nanofiltration a popular and eco-friendly option to soften hard water.

To create self-cleaning nanofiltration membranes out of Lockheed Martin’s networked CNTs, the team needed to overcome the problem of the CNTs’ large pore sizes, which prevented the material from functioning as a nanofiltration membrane.

To achieve this they looked to a second advanced nanofiber material previously developed by Dr. Hashaikeh’s research group, known as networked cellulose. Networked cellulose is a modified type of cellulose made from wood pulp. When dried, the networked cellulose gel shrinks in volume, but maintains its integrity and shape, becoming harder as it shrinks. The research team asserted that the networked cellulose gel could reduce the membrane’s pore sizes while maintaining its structural integrity.

The researchers then mixed the carbon nanostructures with the networked cellulose gel and as the mixture dried, the networked cellulose shrank. The shrinking of the network cellulose in turn pressurized the nanostructures in the membrane. The resulting membrane is strong with much smaller pore sizes. Dr. Hashaikeh reports that the pore size dropped from 60 nanometers to just three nanometers with the addition of the networked cellulose in a paper describing the study, which was published in the journal Desalination last month. Co-authors from Masdar Institute include PhD student Farah Ahmad and postdoctoral researcher Boor Lalia, along with Dr. Nidal Hilal of Swansea University.

Dr. Hashaikeh’s prolific scientific contribution to the field of membrane desalination has led to his recent appointment as an associate editor for the journal Desalination; a position that is essential to the quality of the international journal and its peer review process.

The innovative research conducted by Dr. Hashaikeh and the team will help position Abu Dhabi as a leader in membrane desalination research and technology development. This project has already yielded a patent filing, and is hoped to provide the emirate with novel intellectual property in the critical industry of desalination.

Here are the links and citations for the 2014 and 2017 papers,

A novel in situ membrane cleaning method using periodic electrolysis by Raed Hashaikeh, Boor Singh Lalia, Victor Kochkodan, Nidal Hilal. Journal of Membrane Science Volume 471, 1 December 2014, Pages 149–154 https://doi.org/10.1016/j.memsci.2014.08.017

Electrically conducting nanofiltration membranes based on networked cellulose and carbon nanostructures by Farah Ejaz Ahmed, Boor Singh Lalia, Nidal Hilal, Raed Hashaikeh. Desalination Volume 406, 16 March 2017, Pages 60–66 https://doi.org/10.1016/j.desal.2016.09.005

Both papers a behind a paywall.

‘Hunting’ pharmaceuticals and removing them from water

Pharmaceuticals are not the first pollutants people think of when discussing water pollution but, for those who don’t know, it’s a big issue and scientists at the University of Surrey (UK) have developed a technology they believe will help to relieve the contamination. From an April 10, 2017 University of Surrey press release (also on EurekAlert),

The research involves the detection and removal of pharmaceuticals in or from water, as contamination from pharmaceuticals can enter the aquatic environment as a result of their use for the treatment of humans and animals. This contamination can be excreted unchanged, as metabolites, as unused discharge or by drug manufacturers.

The research has found that a new type of ‘supermolecule’, calix[4], actively seeks certain pharmaceuticals and removes them from water.

Contamination of water is a serious concern for environmental scientists around the world, as substances include hormones from the contraceptive pill, and pesticides and herbicides from allotments. Contamination can also include toxic metals such as mercury, arsenic, or cadmium, which was previously used in paint, or substances that endanger vital species such as bees.

Professor Danil de Namor, University of Surrey Emeritus Professor and leader of the research, said: “Preliminary extraction data are encouraging as far as the use of this receptor for the selective removal of these drugs from water and the possibility of constructing a calix[4]-based sensing devices.

“From here, we can design receptors so that they can bind selectively with pollutants in the water so the pollutants can be effectively removed. This research will allow us to know exactly what is in the water, and from here it will be tested in industrial water supplies, so there will be cleaner water for everyone.

“The research also creates the possibility of using these materials for on-site monitoring of water, without having to transport samples to the laboratory.”

Dr Brendan Howlin, University of Surrey co-investigator, said: “This study allows us to visualise the specific receptor-drug interactions leading to the selective behaviour of the receptor. As well as the health benefits of this research, molecular simulation is a powerful technique that is applicable to a wide range of materials.

“We were very proud that the work was carried out with PhD students and a final year project student, and research activities are already taking place with the Department of Chemical and Processing Engineering (CPI) and the Advanced Technology Institute (ATI).

“We are also very pleased to see that as soon as the paper was published online by the European Journal of Pharmaceutical Sciences, we received invitations to give keynote lectures at two international conferences on pharmaceuticals in Europe later this year.”

That last paragraph is intriguing and it marks the first time I’ve seen that claim in a press release announcing the publication of a piece of research.

Here’s a link to and a citation for the paper,

A calix[4]arene derivative and its selective interaction with drugs (clofibric acid, diclofenac and aspirin) by Angela F Danil de Namor, Maan Al Nuaim, Jose A Villanueva Salas, Sophie Bryant, Brendan Howlin. European Journal of Pharmaceutical Sciences Volume 100, 30 March 2017, Pages 1–8 https://doi.org/10.1016/j.ejps.2016.12.027

This paper is behind a paywall.

Edible water bottles by Ooho!

Courtesy: Skipping Rocks Lab

As far as I’m concerned, that looks more like a breast implant than a water bottle, which, from a psycho-social perspective, could lead to some interesting research papers. It is, in fact a new type of water bottle.  From an April 10, 2017 article by Adele Peters for Fast Company (Note: Links have been removed),

If you run in a race in London in the near future and pass a hydration station, you may be handed a small, bubble-like sphere of water instead of a bottle. The gelatinous packaging, called the Ooho, is compostable–or even edible, if you want to swallow it. And after two years of development, its designers are ready to bring it to market.

Three London-based design students first created a prototype of the edible bottle in 2014 as an alternative to plastic bottles. The idea gained internet hype (though also some scorn for a hilarious video that made the early prototypes look fairly impossible to use without soaking yourself).
The problem it was designed to solve–the number of disposable bottles in landfills–keeps growing. In the U.K. alone, around 16 million are trashed each day; another 19 million are recycled, but still have the environmental footprint of a product made from oil. In the U.S., recycling rates are even lower. …

The new packaging is based on the culinary technique of spherification, which is also used to make fake caviar and the tiny juice balls added to boba tea [bubble tea?]. Dip a ball of ice in calcium chloride and brown algae extract, and you can form a spherical membrane that keeps holding the ice as it melts and returns to room temperature.

An April 25, 2014 article by Kashmira Gander for Independent.co.uk describes the technology and some of the problems that had to be solved before bringing this product to market,

To make the bottle [Ooho!], students at the Imperial College London gave a frozen ball of water a gelatinous layer by dipping it into a calcium chloride solution.

They then soaked the ball in another solution made from brown algae extract to encapsulate the ice in a second membrane, and reinforce the structure.

However, Ooho still has teething problems, as the membrane is only as thick as a fruit skin, and therefore makes transporting the object more difficult than a regular bottle of water.

“This is a problem we’re trying to address with a double container,” Rodrigo García González, who created Ooho with fellow students Pierre Paslier and Guillaume Couche, explained to the Smithsonian. “The idea is that we can pack several individual edible Oohos into a bigger Ooho container [to make] a thicker and more resistant membrane.”

According to Peters’ Fast Company article, the issues have been resolved,

Because the membrane is made from food ingredients, you can eat it instead of throwing it away. The Jell-O-like packaging doesn’t have a natural taste, but it’s possible to add flavors to make it more appetizing.

The package doesn’t have to be eaten every time, since it’s also compostable. “When people try it for the first time, they want to eat it because it’s part of the experience,” says Pierre Paslier, cofounder of Skipping Rocks Lab, the startup developing the packaging. “Then it will be just like the peel of a fruit. You’re not expected to eat the peel of your orange or banana. We are trying to follow the example set by nature for packaging.”

The outer layer of the package is always meant to be peeled like fruit–one thin outer layer of the membrane peels away to keep the inner layer clean and can then be composted. (While compostable cups are an alternative solution, many can only be composted in industrial facilities; the Ooho can be tossed on a simple home compost pile, where it will decompose within weeks).

The company is targeting both outdoor events and cafes. “Where we see a lot of potential for Ooho is outdoor events–festivals, marathons, places where basically there are a lot of people consuming packaging over a very short amount of time,” says Paslier.

I encourage you to read Peters’ article in its entirety if you have the time. You can also find more information on the Skipping Rocks Lab website and on the company’s crowdfunding campaign on CrowdCube.

Cleaning wastewater with fruit peel

A March 23, 2017 news item on phys.org announces a water purification process based on fruit peel,’

A collaborative of researchers has developed a process to clean water containing heavy metals and organic pollutants using a new adsorbent material made from the peels of oranges and grapefruits.

A March 23, 2017 University of Granada press release explains more about the research (Note: Links have been removed),

Researchers from the University of Granada (UGR), and from the Center for Electrochemical Research and Technological Development (Centro de Investigación y Desarrollo Tecnológico en Electroquímica, CIDETEQ) and the Center of Engineering and Industrial Development (Centro de Ingeniería y Desarrollo Industrial, CIDESI), both in Mexico, have developed a process that allows to clean waters containing heavy metals and organic compounds considered pollutants, using a new adsorbent material made from the peels of fruits such as oranges and grapefruits.

Said peels are residues which pose a problem for the food industry, given that they take up a great volume and aren’t very useful nowadays. 38.2 million tons of said fruit peels are estimated to be produced worldwide each year in the food industry.

The research, in which the UGR participates, has served for designing a new process by which, thanks to an Instant Controlled Pressure Drop treatment, it is possible to modify the structure of said residues, giving them adsorbent properties such as a greater porosity and surface area.

Researcher Luis Alberto Romero Cano, from the Carbon Materials Research Team (Grupo de Investigación en Materiales de Carbón) at the Faculty of Science, UGR, explains that, by a subsequent chemical treatment, they “have managed to add functional groups to the material, thus making it selective in order to remove metals and organic pollutants present in water”.

A subsequent research carried out by the authors of this paper has showed that it is possible to pack those new materials in fixed bed columns, in a way similar to a filter by which wastewater runs on a constant flux process, like the usual wastewater treatments. This laboratory-scale study has allowed to obtain parameters to design a large-scale use of said materials.

“The results show a great potential for the use of said materials as adsorbents capable of competing with commercial activated carbon for the adsorption and recovery of metals present in wastewater, in a way that it could be possible to carry out sustainable processes in which products with a great commercial value could be obtained from food industry residues”, Romero Cano says.

Here’s a link to and a citation for the paper,

Biosorbents prepared from orange peels using Instant Controlled Pressure Drop for Cu(II) and phenol removal by Luis A. Romero-Cano, Linda V. Gonzalez-Gutierrez, Leonardo A. Baldenegro-Perez. Industrial Crops and Products Volume 84, June 2016, Pages 344–349  http://dx.doi.org/10.1016/j.indcrop.2016.02.027

I’m not sure why they decided to promote this research so long after it was published but I’m glad they did. It’s always good to see work designed to make use of what is currently waste. By the way, this paper is behind a paywall.

Using a sponge to remove mercury from lake water

I’ve heard of Lake Como in Italy but Como Lake in Minnesota is a new one for me. The Minnesota lake is featured in a March 22, 2017 news item about water and sponges on phys.org,

Mercury is very toxic and can cause long-term health damage, but removing it from water is challenging. To address this growing problem, University of Minnesota College of Food, Agricultural and Natural Sciences (CFANS) Professor Abdennour Abbas and his lab team created a sponge that can absorb mercury from a polluted water source within seconds. Thanks to the application of nanotechnology, the team developed a sponge with outstanding mercury adsorption properties where mercury contaminations can be removed from tap, lake and industrial wastewater to below detectable limits in less than 5 seconds (or around 5 minutes for industrial wastewater). The sponge converts the contamination into a non-toxic complex so it can be disposed of in a landfill after use. The sponge also kills bacterial and fungal microbes.

Think of it this way: If Como Lake in St. Paul was contaminated with mercury at the EPA limit, the sponge needed to remove all of the mercury would be the size of a basketball.

A March 16, 2017 University of Minnesota news release, which originated the news item, explains why this discovery is important for water supplies in the state of Minnesota,

This is an important advancement for the state of Minnesota, as more than two thirds of the waters on Minnesota’s 2004 Impaired Waters List are impaired because of mercury contamination that ranges from 0.27 to 12.43 ng/L (the EPA limit is 2 ng/L). Mercury contamination of lake waters results in mercury accumulation in fish, leading the Minnesota Department of Health to establish fish consumption guidelines. A number of fish species store-bought or caught in Minnesota lakes are not advised for consumption more than once a week or even once a month. In Minnesota’s North Shore, 10 percent of tested newborns had mercury concentrations above the EPA reference dose for methylmercury (the form of mercury found in fish). This means that some pregnant women in the Lake Superior region, and in Minnesota, have mercury exposures that need to be reduced.  In addition, a reduced deposition of mercury is projected to have economic benefits reflected by an annual state willingness-to-pay of $212 million in Minnesota alone.

According to the US-EPA, cutting mercury emissions to the latest established effluent limit standards would result in 130,000 fewer asthma attacks, 4,700 fewer heart attacks, and 11,000 fewer premature deaths each year. That adds up to at least $37 billion to $90 billion in annual monetized benefits annually.

In addition to improving air and water quality, aquatic life and public health, the new technology would have an impact on inspiring new regulations. Technology shapes regulations, which in turn determine the value of the market. The 2015 EPA Mercury and Air Toxics Standards regulation was estimated to cost the industry around of $9.6 billion annually in 2020. The new U of M technology has a potential of bringing this cost down and make it easy for the industry to meet regulatory requirements.

Research by Abbas and his team was funded by the MnDRIVE Global Food Venture, MnDRIVE Environment, and USDA-NIFA. They currently have three patents on this technology. To learn more, visit www.abbaslab.com.

Here’s a link to and a citation for the paper,

A Nanoselenium Sponge for Instantaneous Mercury Removal to Undetectable Levels by Snober Ahmed, John Brockgreitens, Ke Xu, and Abdennour Abbas. Advanced Functional Materials DOI: 10.1002/adfm.201606572 Version of Record online: 6 MAR 2017

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Desalination of sea water with a graphene sieve

The proposed use of graphene membranes for water purification and remediation isn’t new (I have a July 20, 2015 posting which covers some of this field of interest). However, there’s this April 3, 2017 news item on ScienceDaily announcing some new work on graphene and desalination at the University of Manchester,

Graphene-oxide membranes have attracted considerable attention as promising candidates for new filtration technologies. Now the much sought-after development of making membranes capable of sieving common salts has been achieved.

New research demonstrates the real-world potential of providing clean drinking water for millions of people who struggle to access adequate clean water sources.

The new findings from a group of scientists at The University of Manchester were published today in the journal Nature Nanotechnology. Previously graphene-oxide membranes have shown exciting potential for gas separation and water filtration.

An April 3, 2017 University of Manchester press release (also on EurekAlert), which originated the news item, expands on the theme,

Graphene-oxide membranes developed at the National Graphene Institute have already demonstrated the potential of filtering out small nanoparticles, organic molecules, and even large salts. Until now, however, they couldn’t be used for sieving common salts used in desalination technologies, which require even smaller sieves.

Previous research at The University of Manchester found that if immersed in water, graphene-oxide membranes become slightly swollen and smaller salts flow through the membrane along with water, but larger ions or molecules are blocked.

The Manchester-based group have now further developed these graphene membranes and found a strategy to avoid the swelling of the membrane when exposed to water. The pore size in the membrane can be precisely controlled which can sieve common salts out of salty water and make it safe to drink.

As the effects of climate change continue to reduce modern city’s water supplies, wealthy modern countries are also investing in desalination technologies. Following the severe floods in California major wealthy cities are also looking increasingly to alternative water solutions.

When the common salts are dissolved in water, they always form a ‘shell’ of water molecules around the salts molecules. This allows the tiny capillaries of the graphene-oxide membranes to block the salt from flowing along with the water. Water molecules are able to pass through the membrane barrier and flow anomalously fast which is ideal for application of these membranes for desalination.

Professor Rahul Nair, at The University of Manchester said: “Realisation of scalable membranes with uniform pore size down to atomic scale is a significant step forward and will open new possibilities for improving the efficiency of desalination technology.

“This is the first clear-cut experiment in this regime. We also demonstrate that there are realistic possibilities to scale up the described approach and mass produce graphene-based membranes with required sieve sizes.”

Mr. Jijo Abraham and Dr. Vasu Siddeswara Kalangi were the joint-lead authors on the research paper: “The developed membranes are not only useful for desalination, but the atomic scale tunability of the pore size also opens new opportunity to fabricate membranes with on-demand filtration capable of filtering out ions according to their sizes.” said Mr. Abraham.

By 2025 the UN expects that 14% of the world’s population will encounter water scarcity. This technology has the potential to revolutionise water filtration across the world, in particular in countries which cannot afford large scale desalination plants.

It is hoped that graphene-oxide membrane systems can be built on smaller scales making this technology accessible to countries which do not have the financial infrastructure to fund large plants without compromising the yield of fresh water produced.

Courtesy of the University of Manchester

I believe the previous image is an artist’s rendering of the graphene-oxide membrane trapping salt as water moves through it.

Here’s a link to and a citation for the paper,

Tunable sieving of ions using graphene oxide membranes by Jijo Abraham, Kalangi S. Vasu, Christopher D. Williams, Kalon Gopinadhan, Yang Su, Christie T. Cherian, James Dix, Eric Prestat, Sarah J. Haigh, Irina V. Grigorieva, Paola Carbone, Andre K. Geim, & Rahul R. Nair. Nature Nanotechnology (2017) doi:10.1038/nnano.2017.21 Published online 03 April 2017

This paper is open access provided you sign up (or have already signed up) for a free registration with nature.com.

Understanding nanotechnology with Timbits; a peculiarly Canadian explanation

For the uninitiated, Timbits are also known as donut holes. Tim Hortons, founded by ex-National Hockey League player Tim Horton who has since deceased, has taken hold in the Canada’s language and culture such that one of our scientists trying to to explain nanotechnology thought it would be best understood in terms of Timbits. From a Jan. 14, 2017 article (How nanotechnology could change our lives) by Vanessa Lu for thestar.com,

The future is all in the tiny.

Known as nanoparticles, these are the tiniest particles, so small that we can’t see them or even imagine how small they are.

University of Waterloo’s Frank Gu paints a picture of their scale.

“Take a Timbit and start slicing it into smaller and smaller pieces, so small that every Canadian — about 35 million of us — can hold a piece of the treat,” he said. “And those tiny pieces are still a little bigger than a nanoparticle.”

For years, consumers have seen the benefits of nanotechnology in everything from shrinking cellphones to ultrathin televisions. Apple’s iPhones have become more powerful as they have become smaller — where a chip now holds billions of transistors.

“As you go smaller, it creates less footprint and more power,” said Gu, who holds the Canada research chair in advanced targeted delivery systems. “FaceTime, Skype — they are all powered by nanotechnology, with their retina display.”

Lu wrote a second January 14, 2017 article (Researchers developing nanoparticles to purify water) for thestar.com,

When scientists go with their gut or act on a hunch, it can pay off.

For Tim Leshuk, a PhD student in nanotechnology at the University of Waterloo, he knew it was a long shot.

Leshuk had been working with Frank Gu, who leads a nanotechnology research group, on using tiny nanoparticles that have been tweaked with certain properties to purify contaminated water.

Leshuk was working on the process, treating dirty water such as that found in Alberta’s oilsands, with the nanoparticles combined with ultraviolet light. He wondered what might happen if exposed to actual sunlight.

“I didn’t have high hopes,” he said. “For the heck of it, I took some beakers out and put them on the roof. And when I came back, it was far more effective that we had seen with regular UV light.

“It was high-fives all around,” Leshuk said. “It’s not like a Brita filter or a sponge that just soaks up pollutants. It completely breaks them down.”

Things are accelerating quickly, with a spinoff company now formally created called H2nanO, with more ongoing tests scheduled. The research has drawn attention from oilsands companies, and [a] large pre-pilot project to be funded by the Canadian Oil Sands Innovation Alliance is due to get under way soon.

The excitement comes because it’s an entirely green process, converting solar energy for cleanup, and the nanoparticle material is reuseable, over and over.

It’s good to see a couple of articles about nanotechnology. The work by Tim Leshuk was highlighted here in a Dec. 1, 2015 posting titled:  New photocatalytic approach to cleaning wastewater from oil sands. I see the company wasn’t mentioned in the posting so, it must be new; you can find H2nanO here.

Discussion of a divisive topic: the Oilsands

As for the oilsands, it’s been an interesting few days with the Prime Minister’s (Justin Trudeau) suggestion that dependence would be phased out causing a furor of sorts. From a Jan. 13, 2017 article by James Wood for the Calgary Herald,

Prime Minister Justin Trudeau’s musings about phasing out the oilsands Friday [Jan. 13, 2017] were met with a barrage of criticism from Alberta’s conservative politicians and a pledge from Premier Rachel Notley that the province’s energy industry was “not going anywhere, any time soon.”

Asked at a town hall event in Peterborough [Ontario] about the federal government’s recent approval of Kinder Morgan’s Trans Mountain pipeline expansion, Trudeau reiterated his longstanding remarks that he is attempting to balance economic and environmental concerns.

“We can’t shut down the oilsands tomorrow. We need to phase them out. We need to manage the transition off of our dependence on fossil fuels but it’s going to take time and in the meantime we have to manage that transition,” he added.

Northern Alberta’s oilsands are a prime target for environmentalists because of their significant output of greenhouse gas emissions linked to global climate change.

Trudeau, who will be in Calgary for a cabinet retreat on Jan. 23 and 24 [2017], also said again that it is the responsibility of the national government to get Canadian resources to market.

Meanwhile, Jane Fonda, Hollywood actress, weighed in on the issue of the Alberta oilsands with this (from a Jan. 11, 2017 article by Tristan Hopper for the National Post),

Fort McMurrayites might have assumed the celebrity visits would stop after the city was swept first by recession, and then by wildfire.

Or when the provincial government introduced a carbon tax and started phasing out coal.

And surely, with Donald Trump in the White House, even the oiliest corner of Canada would shift to the activist back burner.

But no; here comes Jane Fonda.

“We don’t need new pipelines,” she told a Wednesday [Jan. 11, 2017] press conference at the University of Alberta where she also dismissed Prime Minister Justin Trudeau as a “good-looking Liberal” who couldn’t be trusted.

Saying that her voice was joined with the “Indigenous people of Canada,” Fonda explained her trip to Alberta by saying “when you’re famous you can help amplify the voices of people that can’t necessarily get a lot of press people to come out.”

Fonda is in Alberta at the invitation of Greenpeace, which has brought her here in support of the Treaty Alliance Against Tar Sands Expansion — a group of Canadian First Nations and U.S. tribes opposed to new pipelines to the Athabasca oilsands.

Appearing alongside Fonda, at a table with a sign reading “Respect Indigenous Decisions,” was Grand Chief Stewart Phillip, who, as leader of the Union of B.C. Indian Chiefs, has led anti-pipeline protests and litigation in British Columbia.

“The future is going to be incredibly litigious,” he said in reference to the approved expansion of the Trans-Mountain pipeline.

The event also included Grand Chief Derek Nepinak of the Assembly of Manitoba Chiefs, which is leading a legal challenge to federal approval of the Line 3 pipeline.

Although much of Athabasca’s oil production now comes from “steam-assisted gravity drainage” projects that requires minimal surface disturbance, on Tuesday Fonda took the requisite helicopter tour of a Fort McMurray-area open pit mine.

As you can see, there are not going to be any easy answers.

International news bits: Israel and Germany and Cuba and Iran

I have three news bits today.

Germany

From a Nov. 14, 2016 posting by Lynn L. Bergeson and Carla N. Hutton for The National Law Review (Note: A link has been removed),

The German Federal Ministry of Education and Research (BMBF) recently published an English version of its Action Plan Nanotechnology 2020. Based on the success of the Action Plan Nanotechnology over the previous ten years, the federal government will continue the Action Plan Nanotechnology for the next five years.  Action Plan Nanotechnology 2020 is geared towards the priorities of the federal government’s new “High-Tech Strategy” (HTS), which has as its objective the solution of societal challenges by promoting research.  According to Action Plan Nanotechnology 2020, the results of a number of research projects “have shown that nanomaterials are not per se linked with a risk for people and the environment due to their nanoscale properties.”  Instead, this is influenced more by structure, chemical composition, and other factors, and is thus dependent on the respective material and its application.

A Nov. 16, 2016 posting on Out-Law.com provides mores detail about the plan (Note: A link has been removed),

Eight ministries have been responsible for producing a joint plan on nanotechnology every five years since 2006, the Ministry said. The ministries develop a common approach that pools strategies for action and fields of application for nanotechnology, it [Germany’s Federal Ministry of Education and Research] said.

The German public sector currently spends more than €600 million a year on nanotechnology related developments, and 2,200 organisations from industry, services, research and associations are registered in the Ministry’s nanotechnology competence map, the report said.

“There are currently also some 1,100 companies in Germany engaged [in] the use of nanotechnology in the fields of research and development as well as the marketing of commercial products and services. The proportion of SMEs [small to medium enterprises?] is around 75%,” it said.

Nanotechnology-based product innovations play “an increasingly important role in many areas of life, such as health and nutrition, the workplace, mobility and energy production”, and the plan “thus pursues the objective of continuing to exploit the opportunities and potential of nanotechnology in Germany, without disregarding any potential risks to humans and the environment.”, the Ministry said.

Technology law expert Florian von Baum of Pinsent Masons, the law firm behind Out-Law.com said: “The action plan aims to achieve and secure Germany’s critical lead in the still new nanotechnology field and to recognise and use the full potential of nanotechnology while taking into account possible risks and dangers of this new technology.”

..

“With the rapid pace of development and the new applications that emerge every day, the government needs to ensure that the dangers and risks are sufficiently recognised and considered. Nanotechnology will provide great and long-awaited breakthroughs in health and ecological areas, but ethical, legal and socio-economic issues must be assessed and evaluated at all stages of the innovation chain,” von Baum said.

You can find Germany’s Action Plan Nanotechnology 2020 here, all 64 pp.of it.

Israel and Germany

A Nov. 16, 2016 article by Shoshanna Solomon for The Times of Israel announces a new joint (Israel-Germany) nanotechnology fund,

Tsrael and Germany have set up a new three-year, €30 million plan to promote joint nanotechnology initiatives and are calling on companies and entities in both countries to submit proposals for funding for projects in this field.

“Nanotech is the industry of the future in global hi-tech and Israel has set a goal of becoming a leader of this field, while cooperating with leading European countries,” Ilan Peled, manager of Technological Infrastructure Arena at the Israel Innovation Authority, said in a statement announcing the plan.

In the past decade nanotechnology, seen by many as the tech field of the future, has focused mainly on research. Now, however, Israel’s Innovation Authority, which has set up the joint program with Germany, believes the next decade will focus on the application of this research into products — and countries are keen to set up the right ecosystem that will draw companies operating in this field to them.

Over the last decade, the country has focused on creating a “robust research foundation that can support a large industry,” the authority said, with six academic research institutes that are among the world’s most advanced.

In addition, the authority said, there are about 200 new startups that were established over the last decade in the field, many in the development stage.

I know it’s been over 70 years since the events of World War II but this does seem like an unexpected coupling. It is heartening to see that people can resolve the unimaginable within the space of a few generations.

Iran and Cuba

A Nov. 16, 2016 Mehr News Agency press release announces a new laboratory in Cuba,

Iran is ready to build a laboratory center equipped with nanotechnology in one of nano institutes in Cuba, Iran’s VP for Science and Technology Sorena Sattari said Tuesday [Nov. 15, 2016].

Sorena Sattari, Vice-President for Science and Technology, made the remark in a meeting with Fidel Castro Diaz-Balart, scientific adviser to the Cuban president, in Tehran on Tuesday [November 15, 2016], adding that Iran is also ready to present Cuba with a gifted package including educational services related to how to operate the equipment at the lab.

During the meeting, Sattari noted Iran’s various technological achievements including exports of biotechnological medicine to Russia, the extensive nanotechnology plans for high school and university students as well as companies, the presence of about 160 companies active in the field of nanotechnology and the country’s achievements in the field of water treatment.

“We have sealed good nano agreements with Cuba, and are ready to develop our technological cooperation with this country in the field of vaccines and recombinant drugs,” he said.

Sattari maintained that the biggest e-commerce company in the Middle East is situated in Iran, adding “the company which was only established six years ago now sales over $3.5 million in a day, and is even bigger than similar companies in Russia.”

The Cuban official, for his part, welcomed any kind of cooperation with Iran, and thanked the Islamic Republic for its generous proposal on establishing a nanotechnology laboratory in his country.

This coupling is not quite so unexpected as Iran has been cozying up to all kinds of countries in its drive to establish itself as a nanotechnology leader.

The character of water: both types

This is to use an old term, ‘mindblowing’. Apparently, there are two types of the liquid we call water according to a Nov. 10, 2016 news item on phys.org,

There are two types of liquid water, according to research carried out by an international scientific collaboration. This new peculiarity adds to the growing list of strange phenomena in what we imagine is a simple substance. The discovery could have implications for making and using nanoparticles as well as in understanding how proteins fold into their working shape in the body or misfold to cause diseases such as Alzheimer’s or CJD [Creutzfeldt-Jakob Disease].

A Nov. 10, 2016 Inderscience Publishers news release, which originated the news item, expands on the theme,

Writing in the International Journal of Nanotechnology, Oxford University’s Laura Maestro and her colleagues in Italy, Mexico, Spain and the USA, explain how the physical and chemical properties of water have been studied for more than a century and revealed some odd behavior not seen in other substances. For instance, when water freezes it expands. By contrast, almost every other known substance contracts when it is cooled. Water also exists as solid, liquid and gas within a very small temperature range (100 degrees Celsius) whereas the melting and boiling points of most other compounds span a much greater range.

Many of water’s bizarre properties are due to the molecule’s ability to form short-lived connections with each other known as hydrogen bonds. There is a residual positive charge on the hydrogen atoms in the V-shaped water molecule either or both of which can form such bonds with the negative electrons on the oxygen atom at the point of the V. This makes fleeting networks in water possible that are frozen in place when the liquid solidifies. They bonds are so short-lived that they do not endow the liquid with any structure or memory, of course.

The team has looked closely at several physical properties of water like its dielectric constant (how well an electric field can permeate a substance) or the proton-spin lattice relaxation (the process by which the magnetic moments of the hydrogen atoms in water can lose energy having been excited to a higher level). They have found that these phenomena seem to flip between two particular characters at around 50 degrees Celsius, give or take 10 degrees, i.e. from 40 to 60 degrees Celsius. The effect is that thermal expansion, speed of sound and other phenomena switch between two different states at this crossover temperature.

These two states could have important implications for studying and using nanoparticles where the character of water at the molecule level becomes important for the thermal and optical properties of such particles. Gold and silver nanoparticles are used in nanomedicine for diagnostics and as antibacterial agents, for instance. Moreover, the preliminary findings suggest that the structure of liquid water can strongly influence the stability of proteins and how they are denatured at the crossover temperature, which may well have implications for understanding protein processing in the food industry but also in understanding how disease arises when proteins misfold.

Here’s a link to and a citation for the paper,

On the existence of two states in liquid water: impact on biological and nanoscopic systems
by L.M. Maestro, M.I. Marqués, E. Camarillo, D. Jaque, J. García Solé, J.A. Gonzalo, F. Jaque, Juan C. Del Valle, F. Mallamace, H.E. Stanley.
International Journal of Nanotechnology (IJNT), Vol. 13, No. 8/9, 2016 DOI: 10.1504/IJNT.2016.079670

This paper is behind a paywall.