Category Archives: environment

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.

The Swiss come to a better understanding of nanomaterials

Just to keep things interesting, after the report suggesting most of the information that the OECD (Organization for Economic Cooperation and Development) has on nanomaterials is of little value for determining risk (see my April 5, 2017 posting for more) the Swiss government has released a report where they claim an improved understanding of nanomaterials than they previously had due to further research into the matter. From an April 6, 2017 news item on Nanowerk,

In the past six years, the [Swiss] National Research Programme “Opportunities and Risks of Nanomaterials” (NRP 64) intensively studied the development, use, behaviour and degradation of engineered nanomaterials, including their impact on humans and on the environment.

Twenty-three research projects on biomedicine, the environment, energy, construction materials and food demonstrated the enormous potential of engineered nanoparticles for numerous applications in industry and medicine. Thanks to these projects we now know a great deal more about the risks associated with nanomaterials and are therefore able to more accurately determine where and how they can be safely used.

An April 6, 2017 Swiss National Science Foundation press release, which originated the news item, expands on the theme,

“One of the specified criteria in the programme was that every project had to examine both the opportunities and the risks, and in some cases this was a major challenge for the researchers,” explains Peter Gehr, President of the NRP 64 Steering Committee.

One development that is nearing industrial application concerns a building material strengthened with nanocellulose that can be used to produce a strong but lightweight insulation material. Successful research was also carried out in the area of energy, where the aim was to find a way to make lithium-ion batteries safer and more efficient.

Promising outlook for nanomedicine

A great deal of potential is predicted for the field of nanomedicine. Nine of the 23 projects in NRP 64 focused on biomedical applications of nanoparticles. These include their use for drug delivery, for example in the fight against viruses, or as immune modulators in a vaccine against asthma. Another promising application concerns the use of nanomagnets for filtering out harmful metallic substances from the blood. One of the projects demonstrated that certain nanoparticles can penetrate the placenta barrier, which points to potential new therapy options. The potential of cartilage and bone substitute materials based on nanocellulose or nanofibres was also studied.

The examination of potential health risks was the focus of NRP 64. A number of projects examined what happens when nanoparticles are inhaled, while two focused on ingestion. One of these investigated whether the human gut is able to absorb iron more efficiently if it is administered in the form of iron nanoparticles in a food additive, while the other studied silicon nanoparticles as they occur in powdered condiments. It was ascertained that further studies will be required in order to determine the doses that can be used without risking an inflammatory reaction in the gut.

What happens to engineered nanomaterials in the environment?

The aim of the seven projects focusing on environmental impact was to gain a better understanding of the toxicity of nanomaterials and their degradability, stability and accumulation in the environment and in biological systems. Here, the research teams monitored how engineered nanoparticles disseminate along their lifecycle, and where they end up or how they can be discarded.

One of the projects established that 95 per cent of silver nanoparticles that are washed out of textiles are collected in sewage treatment plants, while the remaining particles end up in sewage sludge, which in Switzerland is incinerated. In another project a measurement device was developed to determine how aquatic microorganisms react when they come into contact with nanoparticles.

Applying results and making them available to industry

“The findings of the NRP 64 projects form the basis for a safe application of nanomaterials,” says Christoph Studer from the Federal Office of Public Health. “It has become apparent that regulatory instruments such as testing guidelines will have to be adapted at both national and international level.” Studer has been closely monitoring the research programme in his capacity as the Swiss government’s representative in NRP 64. In this context, the precautionary matrix developed by the government is an important instrument by means of which companies can systematically assess the risks associated with the use of nanomaterials in their production processes.

The importance of standardised characterisation and evaluation of engineered nanomaterials was highlighted by the close cooperation among researchers in the programme. “The research network that was built up in the framework of NRP 64 is functioning smoothly and needs to be further nurtured,” says Professor Bernd Nowack from Empa, who headed one of the 23 projects.

The results of NRP 64 show that new key technologies such as the use of nanomaterials need to be closely monitored through basic research due to the lack of data on its long-term effects. As Peter Gehr points out, “We now know a lot more about the risks of nanomaterials and how to keep them under control. However, we need to conduct additional research to learn what happens when humans and the environment are exposed to engineered nanoparticles over longer periods, or what happens a long time after a one-off exposure.”

You can find out more about the Opportunities and Risks of Nanomaterials; National Research Programme (NRP 64) here.

OECD (Organization for Economic Cooperation and Development) Dossiers on Nanomaterials Are of “Little to No Value for assessing risk?”

The announcement that a significant portion of the OECD’s (Organization for Economic Cooperation and Development) dossiers on 11 nanomaterials have next to no value for assessing risk seems a harsh judgment from the Center for International Environmental Law (CIEL). From a March 1, 2017 posting by Lynn L. Bergeson on the Nanotechnology Now,

On February 23, 2017, the Center for International Environmental Law (CIEL) issued a press release announcing a new report, commissioned by CIEL, the European Environmental Citizens’ Organization for Standardization (ECOS), and the Oeko-Institute, that “shows that most of the information made available by the Sponsorship Testing Programme of the Organisation for Economic Co-operation and Development (OECD) is of little to no value for the regulatory risk assessment of nanomaterials.”

Here’s more from the Feb. 23, 3017 CIEL press release, which originated the posting,

The study published today [Feb. 23, 2017] was delivered by the Institute of Occupational Medicine (IOM) based in Singapore. IOM screened the 11,500 pages of raw data of the OECD dossiers on 11 nanomaterials, and analysed all characterisation and toxicity data on three specific nanomaterials – fullerenes, single-walled carbon nanotubes, and zinc oxide.

“EU policy makers and industry are using the existence of the data to dispel concerns about the potential health and environmental risks of manufactured nanomaterials,” said David Azoulay, Senior Attorney for CIEL. “When you analyse the data, in most cases, it is impossible to assess what material was actually tested. The fact that data exists about a nanomaterial does not mean that the information is reliable to assess the hazards or risks of the material.”

The dossiers were published in 2015 by the OECD’s Working Party on Manufactured Nanomaterials (WPMN), which has yet to draw conclusions on the data quality. Despite this missing analysis, some stakeholders participating in EU policy-making – notably the European Chemicals Agency (ECHA) and the European Commission’s Joint Research Centre – have presented the dossiers as containing information on nano-specific human health and environmental impacts. Industry federations and individual companies have taken this a step further emphasizing that there is enough information available to discard most concerns about potential health or environmental risks of manufactured nanomaterials.

“Our study shows these claims that there is sufficient data available on nanomaterials are not only false, but dangerously so,” said Doreen Fedrigo, Senior Policy Officer of ECOS. ”The lack of nano-specific information in the dossiers means that the results of the tests cannot be used as evidence of no ‘nano-effect’ of the tested material. This information is crucial for regulators and producers who need to know the hazard profile of these materials. Analysing the dossiers has shown that legislation detailing nano-specific information requirements is crucial for the regulatory risk assessment of nanomaterials.”

The report provides important recommendations on future steps in the governance of nanomaterials. “Based on our analysis, serious gaps in current dossiers must be filled in with characterisation information, preparation protocols, and exposure data,” said Andreas Hermann of the Oeko-Institute. “Using these dossiers as they are and ignoring these recommendations would mean making decisions on the safety of nanomaterials based on faulty and incomplete data. Our health and environment requires more from producers and regulators.”

CIEL has an Analysis of OECD WPMN Dossiers Regarding the Availability of Data to Evaluate and Regulate Risk (Dec 2016) webpage which provides more information about the dossiers and about the research into the dossiers and includes links to the report, the executive summer, and the dataset,

The Sponsorship Testing Programme of the Working Party on Manufactured Nanomaterials (WPMN) of the Organisation for Economic Co-operation and Development (OECD) started in 2007 with the aim to test a selection of 13 representative nanomaterials for many endpoints. The main objectives of the programme were to better understand what information on intrinsic properties of the nanomaterials might be relevant for exposure and hazards assessment and assess the validity of OECD chemicals Test Guidelines for nanomaterials. The testing programme concluded in 2015 with the publication of dossiers on 11 nanomaterials: 11,500 pages of raw data to be analysed and interpreted.

The WPMN has not drawn conclusions on the data quality, but some stakeholders participating in EU policy-making – notably the European Chemicals Agency and the European Commission’s Joint Research Centre – presented the dossiers as containing much scientific information that provided a better understanding of their nano-specific human health and environmental impacts. Industry federations and individual companies echoed the views, highlighting that there was enough information available to discard most concerns about potential health or environmental risks of manufactured nanomaterials.

As for the OECD, it concluded, even before the publication of the dossiers, that “many of the existing guidelines are also suitable for the safety assessment of nanomaterials” and “the outcomes (of the sponsorship programme) will provide useful information on the ‘intrinsic properties’ of nanomaterials.”

The Center for International Environmental Law (CIEL), the European Citizens’ Organisation for Standardisation (ECOS) and the Öko-Institut commissioned scientific analysis of these dossiers to assess the relevance of the data for regulatory risk assessment.

The resulting report: Analysis of OECD WPMN dossiers regarding the availability of data to evaluate and regulate risk, provides insights illustratating how most of the information made available by the sponsorship programme is of little to no value in identifying hazards or in assessing risks due to nanomaterials.

The analysis shows that:

  • Most studies and documents in the dossiers contain insufficient characterisation data about the specific nanomaterial addressed (size, particle distribution, surface shape, etc.), making it impossible to assess what material was actually tested.
  • This makes it impossible to make any firm statements regarding the nano-specificity of the hazard data published, or the relationship between observed effects and specific nano-scale properties.
  • Less than 2% of the study records provide detail on the size of the nanomaterial tested. Most studies use mass rather than number or size distribution (so not following scientifically recommended reporting practice).
  • The absence of details on the method used to prepare the nanomaterial makes it virtually impossible to correlate an identified hazard with specific nanomaterial characteristic. Since the studies do not indicate dispersion protocols used, it is impossible to assess whether the final dispersion contained the intended mass concentration (or even the actual presence of nanomaterials in the test system), how much agglomeration may have occurred, and how the preparation protocols may have influenced the size distribution.
  • There is not enough nano-specific information in the dossiers to inform about nano-characteristics of the raw material that influence their toxicology. This information is important for regulators and its absence makes information in the dossier irrelevant to develop read-across guidelines.
  • Only about half of the endpoint study records using OECD Test Guideliness (TGs) were delivered using unaltered OECD TGs, thereby respecting the Guidelines’ requirements. The reasons for modifications of the TGs used in the tests are not clear from the documentation. This includes whether the study record was modified to account for challenges related to specific nanomaterial properties or for other, non-nano-specific reasons.
  • The studies do not contain systematic testing of the influence of nano-specific characteristics on the study outcome, and they do not provide the data needed to assess the effect of nano-scale features on the Test Guidelines. Given the absence of fundamental information on nanomaterial characteristics, the dossiers do not provide evidence of the applicability of existing OECD Test Guidelines to nanomaterials.

The analysis therefore dispels several myths created by some stakeholders following publication of the dossiers and provides important perspective for the governance of nanomaterials. In particular, the analysis makes recommendations to:

  • Systematically assess the validity of existing Test Guidelines for relevance to nanomaterials
  • Develop Test Guidelines for dispersion and other test preparations
  • Define the minimum characteristics of nanomaterials that need to be reported
  • Support the build-up of exposure database
  • Fill the gaps in current dossiers with characterisation information, preparation protocols and exposure data

Read full report.
Read executive summary.
Download full dataset.

This is not my area of expertise and while I find the language a bit inflammatory, it’s my understanding that there are great gaps in our understanding of nanomaterials and testing for risk assessment has been criticized for many of the reasons pointed out by CIEL, ECOS, and the Oeko-Institute.

You can find out more about CIEL here; ECOS here; and the Oeko-Institute (also known as Öko-Institute) here.

Would you like to invest in the Argonne National Laboratory’s reusable oil spill sponge?

A March 7, 2017 news item on phys.org describes some of the US Argonne National Laboratory’s research into oil spill cleanup technology,

When the Deepwater Horizon drilling pipe blew out seven years ago, beginning the worst oil spill [BP oil spill in the Gulf of Mexico] in U.S. history, those in charge of the recovery discovered a new wrinkle: the millions of gallons of oil bubbling from the sea floor weren’t all collecting on the surface where it could be skimmed or burned. Some of it was forming a plume and drifting through the ocean under the surface.

Now, scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have invented a new foam, called Oleo Sponge, that addresses this problem. The material not only easily adsorbs oil from water, but is also reusable and can pull dispersed oil from the entire water column—not just the surface.

A March 6, 2017 Argonne National Laboratory news release (also on EurekAlert) by Louise Lerner, which originated the news item, provides more information about the work,

“The Oleo Sponge offers a set of possibilities that, as far as we know, are unprecedented,” said co-inventor Seth Darling, a scientist with Argonne’s Center for Nanoscale Materials and a fellow of the University of Chicago’s Institute for Molecular Engineering.

We already have a library of molecules that can grab oil, but the problem is how to get them into a useful structure and bind them there permanently.

The scientists started out with common polyurethane foam, used in everything from furniture cushions to home insulation. This foam has lots of nooks and crannies, like an English muffin, which could provide ample surface area to grab oil; but they needed to give the foam a new surface chemistry in order to firmly attach the oil-loving molecules.

Previously, Darling and fellow Argonne chemist Jeff Elam had developed a technique called sequential infiltration synthesis, or SIS, which can be used to infuse hard metal oxide atoms within complicated nanostructures.

After some trial and error, they found a way to adapt the technique to grow an extremely thin layer of metal oxide “primer” near the foam’s interior surfaces. This serves as the perfect glue for attaching the oil-loving molecules, which are deposited in a second step; they hold onto the metal oxide layer with one end and reach out to grab oil molecules with the other.

The result is Oleo Sponge, a block of foam that easily adsorbs oil from the water. The material, which looks a bit like an outdoor seat cushion, can be wrung out to be reused—and the oil itself recovered.

Oleo Sponge

At tests at a giant seawater tank in New Jersey called Ohmsett, the National Oil Spill Response Research & Renewable Energy Test Facility, the Oleo Sponge successfully collected diesel and crude oil from both below and on the water surface.

“The material is extremely sturdy. We’ve run dozens to hundreds of tests, wringing it out each time, and we have yet to see it break down at all,” Darling said.

Oleo Sponge could potentially also be used routinely to clean harbors and ports, where diesel and oil tend to accumulate from ship traffic, said John Harvey, a business development executive with Argonne’s Technology Development and Commercialization division.

Elam, Darling and the rest of the team are continuing to develop the technology.

“The technique offers enormous flexibility, and can be adapted to other types of cleanup besides oil in seawater. You could attach a different molecule to grab any specific substance you need,” Elam said.

The team is actively looking to commercialize [emphasis mine] the material, Harvey said; those interested in licensing the technology or collaborating with the laboratory on further development may contact partners@anl.gov.

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

Advanced oil sorbents using sequential infiltration synthesis by Edward Barry, Anil U. Mane, Joseph A. Libera, Jeffrey W. Elam, and Seth B. Darling. J. Mater. Chem. A, 2017,5, 2929-2935 DOI: 10.1039/C6TA09014A First published online 11 Jan 2017

This paper is behind a paywall.

The two most recent posts here featuring oil spill technology are my Nov. 3, 2016 piece titled: Oil spill cleanup nanotechnology-enabled solution from A*STAR and my Sept. 15, 2016 piece titled: Canada’s Ingenuity Lab receives a $1.7M grant to develop oil recovery system for oil spills. I hope that one of these days someone manages to commercialize at least one of the new oil spill technologies. It seems that there hasn’t been much progress since the BP (Deepwater Horizon) oil spill. If someone has better information than I do about the current state of oil spill cleanup technologies, please do leave a comment.

Metamaterial could supply air conditioning with zero energy consumption

This is exciting provided they can scale up the metamaterial for industrial use. A Feb. 9, 2017 news item on Nanowerk announces a new metamaterial that could change air conditioning  from the University of Colorado at Boulder (Note: A link has been removed),

A team of University of Colorado Boulder engineers has developed a scalable manufactured metamaterial — an engineered material with extraordinary properties not found in nature — to act as a kind of air conditioning system for structures. It has the ability to cool objects even under direct sunlight with zero energy and water consumption.

When applied to a surface, the metamaterial film cools the object underneath by efficiently reflecting incoming solar energy back into space while simultaneously allowing the surface to shed its own heat in the form of infrared thermal radiation.

The new material, which is described today in the journal Science (“Scalable-manufactured randomized glass-polymer hybrid metamaterial for daytime radiative cooling”), could provide an eco-friendly means of supplementary cooling for thermoelectric power plants, which currently require large amounts of water and electricity to maintain the operating temperatures of their machinery.

A Feb. 9, 2017 University of Colorado at Boulder news release (also on EurekAlert), which originated the news item, expands on the theme (Note: Links have been removed),

The researchers’ glass-polymer hybrid material measures just 50 micrometers thick — slightly thicker than the aluminum foil found in a kitchen — and can be manufactured economically on rolls, making it a potentially viable large-scale technology for both residential and commercial applications.

“We feel that this low-cost manufacturing process will be transformative for real-world applications of this radiative cooling technology,” said Xiaobo Yin, co-director of the research and an assistant professor who holds dual appointments in CU Boulder’s Department of Mechanical Engineering and the Materials Science and Engineering Program. Yin received DARPA’s [US Defense Advanced Research Projects Agency] Young Faculty Award in 2015.

The material takes advantage of passive radiative cooling, the process by which objects naturally shed heat in the form of infrared radiation, without consuming energy. Thermal radiation provides some natural nighttime cooling and is used for residential cooling in some areas, but daytime cooling has historically been more of a challenge. For a structure exposed to sunlight, even a small amount of directly-absorbed solar energy is enough to negate passive radiation.

The challenge for the CU Boulder researchers, then, was to create a material that could provide a one-two punch: reflect any incoming solar rays back into the atmosphere while still providing a means of escape for infrared radiation. To solve this, the researchers embedded visibly-scattering but infrared-radiant glass microspheres into a polymer film. They then added a thin silver coating underneath in order to achieve maximum spectral reflectance.

“Both the glass-polymer metamaterial formation and the silver coating are manufactured at scale on roll-to-roll processes,” added Ronggui Yang, also a professor of mechanical engineering and a Fellow of the American Society of Mechanical Engineers.

“Just 10 to 20 square meters of this material on the rooftop could nicely cool down a single-family house in summer,” said Gang Tan, an associate professor in the University of Wyoming’s Department of Civil and Architectural Engineering and a co-author of the paper.

In addition to being useful for cooling of buildings and power plants, the material could also help improve the efficiency and lifetime of solar panels. In direct sunlight, panels can overheat to temperatures that hamper their ability to convert solar rays into electricity.

“Just by applying this material to the surface of a solar panel, we can cool the panel and recover an additional one to two percent of solar efficiency,” said Yin. “That makes a big difference at scale.”

The engineers have applied for a patent for the technology and are working with CU Boulder’s Technology Transfer Office to explore potential commercial applications. They plan to create a 200-square-meter “cooling farm” prototype in Boulder in 2017.

The invention is the result of a $3 million grant awarded in 2015 to Yang, Yin and Tang by the Energy Department’s Advanced Research Projects Agency-Energy (ARPA-E).

“The key advantage of this technology is that it works 24/7 with no electricity or water usage,” said Yang “We’re excited about the opportunity to explore potential uses in the power industry, aerospace, agriculture and more.”

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

Scalable-manufactured randomized glass-polymer hybrid metamaterial for daytime radiative cooling by Yao Zhai, Yaoguang Ma, Sabrina N. David, Dongliang Zhao, Runnan Lou, Gang Tan, Ronggui Yang, Xiaobo Yin. Science  09 Feb 2017: DOI: 10.1126/science.aai7899

This paper is behind a paywall.

Members of the research team show off the metamaterial (?) Courtesy: University of Colorado at Boulder

I added the caption to this image, which was on the University of Colorado at Boulder’s home page where it accompanied the news release headline on the rotating banner.