Category Archives: environment

Generating power from polluted air

I have no idea how viable this concept might be but it is certainly appealing, From a May 8, 2017 news item on Nanowerk (Note: A link has been removed),

Researchers from the University of Antwerp and KU Leuven (University of Leuven), Belgium, have succeeded in developing a process that purifies air and, at the same time, generates power. The device must only be exposed to light in order to function (ChemSusChem, “Harvesting Hydrogen Gas from Air Pollutants with an Unbiased Gas Phase Photoelectrochemical Cell”).

Caption: The new device must only be exposed to light in order to purify air and generate power. Credit: UAntwerpen and KU Leuven

A May 8, 2017 University of Leuven press release (also on EurekAlert), which originated the news item, describes this nifty research in slightly more detail,

“We use a small device with two rooms separated by a membrane,” explains Professor Sammy Verbruggen (UAntwerp/KU Leuven). “Air is purified on one side, while on the other side hydrogen gas is produced from a part of the degradation products. This hydrogen gas can be stored and used later as fuel, as is already being done in some hydrogen buses, for example.”

In this way, the researchers respond to two major social needs: clean air and alternative energy production. The heart of the solution lies at the membrane level, where the researchers use specific nanomaterials. “These catalysts are capable of producing hydrogen gas and breaking down air pollution,” explains Professor Verbruggen. “In the past, these cells were mostly used to extract hydrogen from water. We have now discovered that this is also possible, and even more efficient, with polluted air.”

It seems to be a complex process, but it is not: the device must only be exposed to light. The researchers’ goal is to be able to use sunlight, as the processes underlying the technology are similar to those found in solar panels. The difference here is that electricity is not generated directly, but rather that air is purified while the generated power is stored as hydrogen gas.

“We are currently working on a scale of only a few square centimetres. At a later stage, we would like to scale up our technology to make the process industrially applicable. We are also working on improving our materials so we can use sunlight more efficiently to trigger the reactions. “

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

Harvesting Hydrogen Gas from Air Pollutants with an Unbiased Gas Phase Photoelectrochemical Cell. by  Prof. Dr. Sammy W. Verbruggen, Myrthe Van Hal1, Tom Bosserez, Dr. Jan Rongé, Dr. Birger Hauchecorne, Prof. Dr. Johan A. Martens, and Prof. Dr. Silvia Lenaerts. ChemSusChem Volume 10, Issue 7, pages 1413–1418, April 10, 2017 DOI: 10.1002/cssc.201601806 Version of Record online: 6 MAR 2017

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

This paper is behind a paywall.

Nanoparticle behaviour in the environment unpredictable

These Swiss researchers took on a fairly massive project according to an April 19, 2017 news item on ScienceDaily,

The nanotech industry is booming. Every year, several thousands of tonnes of man-made nanoparticles are produced worldwide; sooner or later, a certain part of them will end up in bodies of water or soil. But even experts find it difficult to say exactly what happens to them there. It is a complex question, not only because there are many different types of man-made (engineered) nanoparticles, but also because the particles behave differently in the environment depending on the prevailing conditions.

Researchers led by Martin Scheringer, Senior Scientist at the Department of Chemistry and Applied Biosciences, wanted to bring some clarity to this issue. They reviewed 270 scientific studies, and the nearly 1,000 laboratory experiments described in them, looking for patterns in the behaviour of engineered nanoparticles. The goal was to make universal predictions about the behaviour of the particles.

An April 19, 2017ETH Zurich press release by Fabio Bergamin (also on EurekAlert), which originated the news item, elaborates,

Particles attach themselves to everything

However, the researchers found a very mixed picture when they looked at the data. “The situation is more complex than many scientists would previously have predicted,” says Scheringer. “We need to recognise that we can’t draw a uniform picture with the data available to us today.”

Nicole Sani-Kast, a doctoral student in Scheringer’s group and first author of the analysis published in the journal PNAS [Proceedings of the National Academy of Sciences], adds: “Engineered nanoparticles behave very dynamically and are highly reactive. They attach themselves to everything they find: to other nanoparticles in order to form agglomerates, or to other molecules present in the environment.”

Network analysis

To what exactly the particles react, and how quickly, depends on various factors such as the acidity of the water or soil, the concentration of the existing minerals and salts, and above all, the composition of the organic substances dissolved in the water or present in the soil. The fact that the engineered nanoparticles often have a surface coating makes things even more complicated. Depending on the environmental conditions, the particles retain or lose their coating, which in turn influences their reaction behaviour.

To evaluate the results available in the literature, Sani-Kast used a network analysis for the first time in this research field. It is a technique familiar in social research for measuring networks of social relations, and allowed her to show that the data available on engineered nanoparticles is inconsistent, insufficiently diverse and poorly structured.

More method for machine learning

“If more structured, consistent and sufficiently diverse data were available, it may be possible to discover universal patterns using machine learning methods,” says Scheringer, “but we’re not there yet.” Enough structured experimental data must first be available.

“In order for the scientific community to carry out such experiments in a systematic and standardised manner, some kind of coordination is necessary,” adds Sani-Kast, but she is aware that such work is difficult to coordinate. Scientists are generally well known for preferring to explore new methods and conditions rather than routinely performing standardized experiments.

[additional material]

Distinguishing man-made and natural nanoparticles

In addition to the lack of systematic research, there is also a second tangible problem in researching the behaviour of engineered nanoparticles: many engineered nanoparticles consist of chemical compounds that occur naturally in the soil. So far it has been difficult to measure the engineered particles in the environment since it is hard to distinguish them from naturally occurring particles with the same chemical composition.

However, researchers at ETH Zurich’s Department of Chemistry and Applied Biosciences, under the direction of ETH Professor Detlef Günther, have recently established an effective method that makes such a distinction possible in routine investigations. They used a state-of-the-art and highly sensitive mass spectrometry technique (called spICP-TOF mass spectrometry) to determine which chemical elements make up individual nanoparticles in a sample.

In collaboration with scientists from the University of Vienna, the ETH researchers applied the method to soil samples with natural cerium-containing particles, into which they mixed engineered cerium dioxide nanoparticles. Using machine learning methods, which were ideally suited to this particular issue, the researchers were able to identify differences in the chemical fingerprints of the two particle classes. “While artificially produced nanoparticles often consist of a single compound, natural nanoparticles usually still contain a number of additional chemical elements,” explains Alexander Gundlach-Graham, a postdoc in Günther’s group.

The new measuring method is very sensitive: the scientists were able to measure engineered particles in samples with up to one hundred times more natural particles.

The researchers have produced a visualization of their network analysis,

The researchers evaluated the experimental data published in the scientific literature using a network analysis. This analysis reveals which types of nanoparticles (blue) have been studied under which environmental conditions (red). (Visualisations: Thomas Kast)

Here are links and citation for two papers associated with this research,

A network perspective reveals decreasing material diversity in studies on nanoparticle interactions with dissolved organic matter by Nicole Sani-Kast, Jérôme Labille, Patrick Ollivier, Danielle Slomberg, Konrad Hungerbühler, and Martin Scheringer. PNAS 2017, 114: E1756-E1765, DOI: 10.1073/pnas.1608106114

Single-particle multi-element fingerprinting (spMEF) using inductively-coupled plasma time-of-flight mass spectrometry (ICP-TOFMS) to identify engineered nanoparticles against the elevated natural background in soils by Antonia Praetorius, Alexander Gundlach-Graham, Eli Goldberg, Willi Fabienke, Jana Navratilova, Andreas Gondikas, Ralf Kaegi, Detlef Günther, Thilo Hofmann, and Frank von der Kammer. Environonmental Science: Nano 2017, 4: 307-314, DOI: 10.1039/c6en00455e

Both papers are 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.

Recycle electronic waste by crushing it into nanodust

Given the issues with e-waste this work seems quite exciting. From a March 21, 2017 Rice University news release (also on EurekAlert), Note: Links have been removed,

Researchers at Rice University and the Indian Institute of Science have an idea to simplify electronic waste recycling: Crush it into nanodust.

Specifically, they want to make the particles so small that separating different components is relatively simple compared with processes used to recycle electronic junk now.

Chandra Sekhar Tiwary, a postdoctoral researcher at Rice and a researcher at the Indian Institute of Science in Bangalore, uses a low-temperature cryo-mill to pulverize electronic waste – primarily the chips, other electronic components and polymers that make up printed circuit boards (PCBs) — into particles so small that they do not contaminate each other.

Then they can be sorted and reused, he said.

Circuit boards from electronics, like computer mice, can be crushed into nanodust by a cryo-mill, according to researchers at Rice and the Indian Institute of Science. The dust can then be easily separated into its component elements for recycling.

Circuit boards from electronics, like computer mice, can be crushed into nanodust by a cryo-mill, according to researchers at Rice and the Indian Institute of Science. The dust can then be easily separated into its component elements for recycling. Courtesy of the Ajayan Research Group

The process is the subject of a Materials Today paper by Tiwary, Rice materials scientist Pulickel Ajayan and Indian Institute professors Kamanio Chattopadhyay and D.P. Mahapatra. 

The researchers intend it to replace current processes that involve dumping outdated electronics into landfills, or burning or treating them with chemicals to recover valuable metals and alloys. None are particularly friendly to the environment, Tiwary said.

“In every case, the cycle is one way, and burning or using chemicals takes a lot of energy while still leaving waste,” he said. “We propose a system that breaks all of the components – metals, oxides and polymers – into homogenous powders and makes them easy to reuse.”

The researchers estimate that so-called e-waste will grow by 33 percent over the next four years, and by 2030 will weigh more than a billion tons. Nearly 80 to 85 percent of often-toxic e-waste ends up in an incinerator or a landfill, Tiwary said, and is the fastest-growing waste stream in the United States, according to the Environmental Protection Agency.

The answer may be scaled-up versions of a cryo-mill designed by the Indian team that, rather than heating them, keeps materials at ultra-low temperatures during crushing.

Cold materials are more brittle and easier to pulverize, Tiwary said. “We take advantage of the physics. When you heat things, they are more likely to combine: You can put metals into polymer, oxides into polymers. That’s what high-temperature processing is for, and it makes mixing really easy.

A transparent piece of epoxy, left, compared to epoxy with e-waste reinforcement at right. A cryo-milling process developed at Rice University and the Indian Institute of Science simplifies the process of separating and recycling electronic waste.

A transparent piece of epoxy, left, compared to epoxy with e-waste reinforcement at right. A cryo-milling process developed at Rice University and the Indian Institute of Science simplifies the process of separating and recycling electronic waste. Courtesy of the Ajayan Research Group

“But in low temperatures, they don’t like to mix. The materials’ basic properties – their elastic modulus, thermal conductivity and coefficient of thermal expansion – all change. They allow everything to separate really well,” he said.

The test subjects in this case were computer mice – or at least their PCB innards. The cryo-mill contained argon gas and a single tool-grade steel ball. A steady stream of liquid nitrogen kept the container at 154 kelvins (minus 182 degrees Fahrenheit).

When shaken, the ball smashes the polymer first, then the metals and then the oxides just long enough to separate the materials into a powder, with particles between 20 and 100 nanometers wide. That can take up to three hours, after which the particles are bathed in water to separate them.

“Then they can be reused,” he said. “Nothing is wasted.”

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

Electronic waste recycling via cryo-milling and nanoparticle beneficiation by C.S. Tiwary, S. Kishore, R. Vasireddi, D.R. Mahapatra, P.M. Ajayan, K. Chattopadhyay. Materials Today         http://dx.doi.org/10.1016/j.mattod.2017.01.015 Available online 20 March 2017

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.

European Commission has issued evaluation of nanomaterial risk frameworks and tools

Despite complaints that there should have been more, there has been some research into risks where nanomaterials are concerned. While additional research would be welcome, it’s perhaps more imperative that standardized testing and risk frameworks are developed so, for example, carbon nanotube safety research in Japan can be compared with the similar research in the Netherlands, the US, and elsewhere. This March 15, 2017 news item on Nanowerk features some research analyzing risk assessment frameworks and tools in Europe,

A recent study has evaluated frameworks and tools used in Europe to assess the potential health and environmental risks of manufactured nanomaterials. The study identifies a trend towards tools that provide protocols for conducting experiments, which enable more flexible and efficient hazard testing. Among its conclusions, however, it notes that no existing frameworks meet all the study’s evaluation criteria and calls for a new, more comprehensive framework.

A March 9, 2017 news alert in the European Commission’s Science for Environment Policy series, which originated the news item, provides more detail (Note: Links have been removed),

Nanotechnology is identified as a key emerging technology in the EU’s growth strategy, Europe 2020. It has great potential to contribute to innovation and economic growth and many of its applications have already received large investments. However,there are some uncertainties surrounding the environmental, health and safety risks of manufactured nanomaterials. For effective regulation, careful scientific analysis of their potential impacts is needed, as conducted through risk assessment exercises.

This study, conducted under the EU-funded MARINA project1, reviewed existing frameworks and tools for risk assessing manufactured nanomaterials. The researchers define a framework as a ‘conceptual paradigm’ of how a risk assessment should be conducted and understood, and give the REACH chemical safety assessment as an example. Tools are defined as implements used to carry out a specific task or function, such as experimental protocols, computer models or databases.

In all, 12 frameworks and 48 tools were evaluated. These were identified from other studies and projects. The frameworks were assessed against eight criteria which represent different strengths, such as whether they consider properties specific to nanomaterials, whether they consider the entire life cycle of a nanomaterial and whether they include careful planning and prioritise objectives before the risk assessment is conducted.

The tools were assessed against seven criteria, such as ease of use, whether they provide quantitative information and if they clearly communicate uncertainty in their results. The researchers defined the criteria for both frameworks and tools by reviewing other studies and by interviewing staff at organisations who develop tools.

The evaluation was thus able to produce a list of strengths and areas for improvement for the frameworks and tools, based on whether they meet each of the criteria. Among its many findings, the evaluation showed that most of the frameworks stress that ‘problem formulation’, which sets the goals and scope of an assessment during the planning process, is essential to avoid unnecessary testing. In addition, most frameworks consider routes of exposure in the initial stages of assessment, which is beneficial as it can exclude irrelevant exposure routes and avoid unnecessary tests.

However, none of the frameworks met all eight of the criteria. The study therefore recommends that a new, comprehensive framework is developed that meets all criteria. Such a framework is needed to inform regulation, the researchers say, and should integrate human health and environmental factors, and cover all stages of the life cycle of a product containing nanomaterials.

The evaluation of the tools suggested that many of them are designed to screen risks, and not necessarily to support regulatory risk assessment. However, their strengths include a growing trend in quantitative models, which can assess uncertainty; for example, one tool analysed can identify uncertainties in its results that are due to gaps in knowledge about a material’s origin, characteristics and use.

The researchers also identified a growing trend in tools that provide protocols for experiments, such as identifying materials and test hazards, which are reproducible across laboratories. These tools could lead to a shift from expensive case-by-case testing for risk assessment of manufactured nanomaterials towards a more efficient process based on groupings of nanomaterials; and ‘read-across’ methods, where the properties of one material can be inferred without testing, based on the known properties of a similar material. The researchers do note, however, that although read-across methods are well established for chemical substances, they are still being developed for nanomaterials. To improve nanomaterial read-across methods, they suggest that more data are needed on the links between nanomaterials’ specific properties and their biological effects.

That’s all, folks.

Recycling apples to regenerate bone and cartilage tissue

A March 30, 2017 news item on phys.org announces research utilizing apple waste as a matrix for regenerating bones and cartilage,

Researchers from UPM and CSIC [both organizations are in Spain] have employed waste from the agri-food industry to develop biomaterials that act as matrices to regenerate bone and cartilage tissues, which is of great interest for the treatment of diseases related to aging.

The researchers have produced biocompatible materials from apple pomace resulting from juice production. These materials can be used as 3-D matrices for the regeneration of bone and cartilage tissues, useful in regenerative medicine for diseases such as osteoporosis, arthritis or osteoarthritis, all of them rising due to the increasing average age of the population.

A March 30, 2017 Universidad Politécnica de Madrid (UPM) press release, which originated the news item,, expands on the theme,

Apple pomace is an abundant raw material. The world production of apples was more than 70 million tons in 2015, of which the European Union contributed with more than 15%, while half a million tons of which came from Spain. About 75% of apples can be converted into juice and the rest, known as apple pomace, that contains approximately 20–30% dried matter, is used mainly as animal feed or for compost. Since apple pomace is generated in vast quantities and contains a large fraction of water, it poses storage problems and requires immediate treatments to prevent putrefaction. An alternative of great environmental interest is its transformation into value added commodities, thus reducing the volume of waste.

The procedure of the multivalorization of apple pomace carried out by the UPM and CSIC researchers are based on sequential extractions of different bioactive molecules, such as antioxidants or pectin, to finally obtain the waste from which they prepare a biomaterial with suitable porosity and texture to be used in tissue engineering.

The primary extraction of antioxidants and carbohydrates constitutes 2% of the dry weight of apple pomace and pectin extraction is 10%. The extracted chemical cells have a recognized value as nutraceuticals and pectin is a material of great utility in different medical applications, given its high biocompatibility and being part of antitumor drugs or in the treatment of coetaneous wounds.

Furthermore, it has been found that the materials remaining after antioxidant and pectin removal from apple pomace can still be designed with adequate structure, texture and composition to grow diverse types of cells. In this particularly case, the chosen cells were osteoblasts and chondrocytes, both of them related to the regeneration of bone and cartilage tissues because of their application in regenerative medicine in diseases such as osteoporosis, arthritis or osteoarthritis.

Today, there are products in the market with the same applications, however they have a high price reaching over €100 per gram, while waste used in this work hardly reaches €100 per ton. For this reason, there are consistent incentives to convert this waste into final products of great added value.

According to Milagro Ramos, a female researcher of the study, “with this approach we achieve a double goal, firstly using waste as a renewable raw material of high value and chemical diversity, and secondly, to reduce the impact of such waste accumulation on the environment”.

Thanks to the new materials obtained in this work, researchers are developing new technological applications that allow them to structure customized biomaterials through 3D printing techniques.

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

Multivalorization of apple pomace towards materials and chemicals. Waste to wealth by Malcolm Yates, Milagros Ramos Gomez, Maria A. Martin-Luengo, Violeta Zurdo Ibañez, Ana Maria Martinez Serrano. Journal of Cleaner Production Volume 143, 1 February 2017, Pages 847–853  http://doi.org/10.1016/j.jclepro.2016.12.036

This paper is behind a paywall.