Tag Archives: site remediation

NanoRem: pollution, nanotechnology, and remediation

Canadian soil remediation expert in Australia

Back in my Nov. 4, 2011 posting where I reviewed the third episode in a limited series on nanotechnology, broadcast as a Nature of Things television science programme on Canadian Broadcasting Corporation stations, I noted Dr. Dennis O’Carroll’s soil remediation work in southern Ontario.

There’s more news about professor O’Carroll, currently visiting Australia, in a June 4, 2012 news item on Nanowerk,

“Toxic contamination of soils is an historical problem,” says Dr Denis O’Carroll, a visiting academic at the University of New South Wales (UNSW) Water Research Lab. “Until the 1970s, people wrongly believed that if we put these toxins into the ground they would simply disappear – that the subsurface would act as a natural filtration unit.”

“The possibility of this waste polluting the environment, and potentially contaminating groundwater sources and remaining there for decades was ignored,” he says.

Far from magically disappearing, chemical contaminants from spilled gas and solvents, when not directly polluting surface waters, seep down into the earth, travelling through microscopic soil cracks, where they accumulate and can eventually reach the groundwater table.

Traditional clean-up methods have focussed on pumping out the contaminated water or flushing out toxins with a specially designed cleansing solution, but these are limited by difficulties in accurately pinpointing and accessing locations where contamination has occurred, says O’Carroll.

His approach is to tackle toxic contaminants with nanotechnology. O’Carroll, who is visiting UNSW from the University of Western Ontario in Canada, has been trialling an innovative new groundwater clean-up technology using metal nanoparticles 500 to 5,000 times narrower than a human hair.

There are more details about O’Carroll’s specific innovations in this field in the June 4, 2012 news item. As well, I published, in its entirety (and with permission), an excellent description of nanotechnology-enabled soil remediation by Joe Martin, a graduate student at the University of Michigan, in my March 30, 2012 posting. Here’s a tidbit from Joe’s article,

… The use of iron oxides to adsorb and immobilize metals and arsenic is not a new concept, but nano-particles offer new advantages. When I wrote “adsorb”, I was not making a spelling error; adsorption is a process by which particles adhere to the surface of another material, but do not penetrate into the interior. This makes surface area, not volume, the important characteristic. Nano-particles provide the maximum surface area-to-weight ratio, maximizing the adsorptive surfaces onto which these elements can attach. These adsorptive processes a very effective at binding and immobilizing metals and arsenic, but they do not allow for the removal of the toxic components. This may be less-than-ideal, but in places like Bangladesh, where arsenic contamination of groundwater poses major health risks, it may be just short of a miracle.

There’s an extensive list with links to further reading and videos on the topic of nanotechnology and site remediation at the end of the March 30, 2012 posting.

Phyto and nano soil remediation (part 2: nano)

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For Part 2, I’ve included part of my original introduction (sans the story about the neighbour’s soil and a picture of Joe Martin):

I’m pleased to repost a couple of pieces on soil remediation written by Joe Martin for the Mind the Science Gap (MTSG) blog.

I wrote about the MTSG blog in my Jan. 12, 2012 posting, which focussed on this University of Michigan project designed by Dr. Andrew Maynard for Master’s students in the university’s Public Health program. Very briefly here’s a description of Andrews and the program from the About page,

Mind the Science Gap is a science blog with a difference. For ten weeks between January and April 2012, Masters of Public Health students from the University of Michigan will each be posting weekly articles as they learn how to translate complex science into something a broad audience can understand and appreciate.

Each week, ten students will take a recent scientific publication or emerging area of scientific interest, and write a post on it that is aimed at a non expert and non technical audience. As the ten weeks progress, they will be encouraged to develop their own area of focus and their own style.

…

About the Instructor. Andrew Maynard is Director of the University of Michigan Risk Science Center, and a Professor of Environmental Health Sciences in the School of Public Health. He writes a regular blog on emerging technologies and societal implications at 2020science.org.

Here’s a bit more about Joe Martin,

I am a second year MPH student in Environmental Quality and Health, and after graduation from this program, I will pursue a Ph.D. in soil science. My interests lie in soil science and chemistry, human health and how they interact, especially in regards to agricultural practice and productivity.

Here’s part 2: nano soil remediation or Joe’s Feb. 10, 2012 posting:

Last week I wrote about phytoremediation, and its potential to help us combat and undo soil contamination. But, like any good advanced society, we’re not pinning all our hopes on a single technique. A commenter, Maryse, alerted me to the existence of another promising set of techniques and technologies: nano-remediation.

For those who don’t know, nano-technology is a science which concerns itself with manipulating matter on a very small scale. Nano-particles are commonly described as being between 100 nanometers (nm) to 1nm, though this is hardly a hard and fast rule. (For perspective, a nanometer is one one-millionth of a millimeter. If you aren’t inclined to the metric system, there are roughly four hundred million nanometers per inch.) On such micro-scales, the normal properties of compounds can be altered without changing the actual chemical composition. This allows for many new materials and products, (such as Ross Nanotechnology’s Neverwet Spray,) and for new applications for common materials, (using graphene to make the well-known carbon nanotubes).

When we apply the use of nano-scale particles to the remediation of contaminated soil, we are using nano-remediation. Unlike phytoremediation, this actually encompasses several different strategies which can be broadly classes as adsorptive or reactive. (Mueller and Nowack, 2010) The use of iron oxides to adsorb and immobilize metals and arsenic is not a new concept, but nano-particles offer new advantages. When I wrote “adsorb”, I was not making a spelling error; adsorption is a process by which particles adhere to the surface of another material, but do not penetrate into the interior. This makes surface area, not volume, the important characteristic. Nano-particles provide the maximum surface area-to-weight ratio, maximizing the adsorptive surfaces onto which these elements can attach. These adsorptive processes a very effective at binding and immobilizing metals and arsenic, but they do not allow for the removal of the toxic components. This may be less-than-ideal, but in places like Bangladesh, where arsenic contamination of groundwater poses major health risks, it may be just short of a miracle.

Reactive nano-remediation strategies focus on organic pollutants, and seem to work best for chlorinated solvents such as the infamous PCBs. Nano-scale zero valent iron, or nZVI, is the most widely explored and tested element used in these methods. The nZVI, or sometimes nZVI bound to various organic molecules like polysaccharides or protein chains, force redox reactions which rapidly disassemble the offending molecules.

There are other advantages to these nano-molecular techniques aside from the efficiency with which they bind or destroy the offending pollutants. In reactive remediation, the hyper reactivity nZVI causes it to react with other common and natural elements, such as dissolved oxygen in ground water, or nitrate and sulfate molecules, and in the process this inactivates the nZVI. While this forces multiple applications of the nano-particle (delivered in slurry form, through an injection well), it also prevents unused iron from drifting out of the treatment zone and becoming a pollutant itself. For adsorptive and reactive remediation techniques, that active nano-particles are injected into a well dug into or near the contaminated soil and/or groundwater. When injected as a slurry, the nano-particles can drift along with the flow of ground water, effectively creating an “anti-pollution” plume. In other formulations, the active mixture is made to flow less easily, effectively creating a barrier to filter spreading pollution or through which polluted ground water can be pulled.

There are health risks and concerns associated with the production and use of nano-particles, so some caution and validation is needed before its used everywhere. However, there has already been some successes with nano-remediation. The example of PCB remediation with nZVI is taken from great success the US Air Force has had. (PCB contamination is a legacy of their use as fire-suppressants). Beyond this, while nano-remediation has not been widely applied on surface or near-surface soils, it does enable remediation in deeper soils normally only accessed by “pump-and-treat” methods, (which are expensive and can have decades-long time frames). When coupled with other techniques, (like phytoremediation), it does fit nicely into an expanding tool bag, one with which we as a society and species can use to reverse our impact on the planet, (and our own health).

Further Reading: There was no way for me to represent the full sum of nano-remediation, nevertheless nanotechnology, in this post. It has such potential, and is developing at such a rate that the attention it deserves is better measured in blogs (or perhaps decablogs). So if you are interested in nano-technology or nano-remediation, click through some of the links below.

List of popular blogs: http://www.blogs.com/topten/10-popular-nanotechnology-blogs/, including some very important ones on the health risks of nano-technology.

A cool site listing sites currently using nano-remediation: http://www.nanotechproject.org/inventories/remediation_map/, and another post from the same site dealing with nano-remediation [PEN webcast on site remediation]: http://www.nanotechproject.org/events/archive/remediation/

An excellent peer-reviewed article: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2799454/

Citation: Mueller C and Nowack B. Nanoparticles for Remediation: Solving Big Problems with Little Particles. 2010. Elements, Vol. 6. pp 395-400.

You can read about the other MTSG contributors and find links to their work here.

I have mentioned remediation before on the blog,

soil remediation and Professor Dennis Carroll at the University of Western Ontario in my Nov. 4, 2011 posting

remediation and a patent for Green-nano zero valent iron (G-nZVI) in my June 17, 2011 posting

groundwater remediation and nano zero valent iron (nZVI) at the University of California at Santa Barbara in my March 30, 2011 posting

site remediation and drywall in my Aug. 2, 2010 posting

remediation technologies and oil spills my May 6, 2010 posting

my March 4, 2010 posting (scroll down about 1/2 way) which is a commentary on the Project for Emerging Nanotechnologies (PEN) webcast about site remediation in Joe’s list of resources

Thank you Joe for giving me permission to repost your pieces. For more of Joe’s pieces, Read his posts here –>

Oil-absorbing (nanotechnology-enabled) robots at Venice Biennale?

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MIT (Massachusetts Institute of Technology) researchers are going to be presenting nano-enabled oil-absorbing robots, Seaswarm, at the Venice Biennale , (from the news item on Nanowerk),

Using a cutting edge nanotechnology, researchers at MIT have created a robotic prototype that could autonomously navigate the surface of the ocean to collect surface oil and process it on site.

The system, called Seaswarm, is a fleet of vehicles that may make cleaning up future oil spills both less expensive and more efficient than current skimming methods. MIT’s Senseable City Lab will unveil the first Seaswarm prototype at the Venice Biennale’s Italian Pavilion on Saturday, August 28. The Venice Biennale is an international art, music and architecture festival whose current theme addresses how nanotechnology will change the way we live in 2050.

I did look at the Biennale website for more information about the theme and about Seaswarm but details, at least on the English language version of the website, are nonexistent. (Note: The Venice Biennale was launched in 1895 as an art exhibition. Today the Biennale features, cinema, architecture, theatre, and music as well as art.)

You can find out more about Seaswarm at MIT’s senseable city lab here and/or you can watch this animation,

The animation specifically mentions BP and the Gulf of Mexico oil spill and compares the skimmers used to remove oil from the ocean with Seaswarm skimmers outfitted with nanowire meshes,

The Seaswarm robot uses a conveyor belt covered with a thin nanowire mesh to absorb oil. The fabric, developed by MIT Visiting Associate Professor Francesco Stellacci, and previously featured in a paper published in the journal Nature Nanotechnology, can absorb up to twenty times its own weight in oil while repelling water. By heating up the material, the oil can be removed and burnt locally and the nanofabric can be reused.

“We envisioned something that would move as a ‘rolling carpet’ along the water and seamlessly absorb a surface spill,” said Senseable City Lab Associate Director Assaf Biderman. “This led to the design of a novel marine vehicle: a simple and lightweight conveyor belt that rolls on the surface of the ocean, adjusting to the waves.”

The Seaswarm robot, which is 16 feet long and seven feet wide, uses two square meters of solar panels for self-propulsion. With just 100 watts, the equivalent of one household light bulb, it could potentially clean continuously for weeks.

I’d love to see the prototype in operation not to mention getting a chance to attend La Biennale.

Science festivals in the US; nanoparticles and environmental health and safety report from ENRHES; new technique in molecular biology; PEN’s site remediation webcast commentary

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I just came across a notice for the first ever USA Science and Engineering Festival to be held in Washington, DC, Oct. 10-24, 2010. From the Azonano news item,

Agilent Technologies Inc. (NYSE:A) today announced its support of the USA Science & Engineering Festival, the country’s first national science festival. The event will take place in Washington, D.C., in October 2010. The festival, expected to be a multi-cultural and multi-disciplinary celebration of science in the United States, will offer science and engineering organizations throughout the country the opportunity to present hands-on science activities to inspire the next generation of scientists and engineers. Festival organizers already have engaged more than 350 participants from the nation’s leading science and engineering organizations.

From what I’ve seen of their website, they are using the term multi-disciplinary in a fairly conservative sense, i. e., different science and engineering disciplines are being brought together. This contrasts with the approach used in the World Science Festival, being held in New York, June 2-6, 2010, where they mash together artists as well as scientists from many different disciplines.

Michael Berger at Nanowerk sputters a bit as he comments on the Engineered Nanoparticles Review of Health and Environmental Safety (ENRHES) report,

Before we take a look at the report’s findings, it’s quite remarkable that the authors feel compelled to start their introduction section with this sentence: “Nanotechnology is a sector of the material manufacturing industry that has already created a multibillion $US market, and is widely expected to grow to 1 trillion $US by 2015.” Firstly, a lot of people would argue with the narrow definition of nanotechnology as being a sector of the material manufacturing industry. Secondly, it appears that still no publicly funded report can afford to omit the meaningless and nonsensical reference to a ‘trillion dollar industry by 2015’. It really is astonishing how this claim gets regurgitated over and over again – even by serious scientists – without getting scrutinized (read “Debunking the trillion dollar nanotechnology market size hype”). It would be interesting to know if scientific authors, who otherwise operate in a fact-based world, just accept a number picked out of thin air by some consultants because it helps impress their funders; or if they deliberately use what they know is a fishy number because the politicians and bureaucrats who control the purses are easily fooled by sensational claims like these and keep the funding coming.

Sadly, picking a number out of thin air happens more often than we like to believe. A few years back I was reading a book about food and how it’s changing as we keep manipulating our food products to make them last longer on the shelf, etc. In one chapter of the book, the author chatted with an individual who helped to define high cholesterol. As he told the story, he and his colleagues (scientists all) got in a room and picked a number that was used to define a high cholesterol count. (I will try to find the title of that book, unfortunately the memory escapes me at the moment. ETA: Mar.4.10, the book is by Gina Mellet, Last chance to eat, 2004) I’ve heard variations of this business of picking a number that sounds good before.

As for the rest of the ENRHES report, Berger has this to say,

Thankfully, the rest of the report stands on solid ground.

I’m using those last two words, “solid ground” to eventually ease my way into a discussion about site remediation and the Project on Emerging Nanotechnologies’ (PEN) recent webcast. First, there’s a brief and related item on molecular biology.

Scientists at the University of Chicago are trying to develop a method for understanding how biological processes emerge from molecular interactions. From the news item (which includes an audio file of Andre Dinner, one of the scientists, discussing his work) on physorg.com,

Funded by a $1 million grant from the W.M. Keck Foundation, University of Chicago scientists are aiming to develop a reliable method for determining how biological processes emerge from molecular interactions. The method may permit them to “rewire” the regulatory circuitry of insulin-secreting pancreatic beta cells, which play a major role in type-2 diabetes.

…

A second goal: to control cell behavior and function more generally, which may ultimately culminate in other applications, including the bioremediation of environmental problems.

…

The four scientists [Aaron Dinner, Louis Philipson, Rustem Ismagilov, and Norbert Scherer] share an interest in the collective behavior of cells that emerges from a complex ensemble of atoms and molecules working in concert at different scales of time and space. “In a living system you have this hierarchy of coupled time and length scales,” Dinner said. “How is it that all of these different dynamics at one time and length scale get coupled to dynamics at another scale?”

In other words, how does life begin? I know that’s not the question they’re asking but this work has to lead in that direction and I imagine the synthetic biology people are watching with much interest.

In the more immediate future, this work in molecular biology may lead to better bioremediation, which was the topic at hand on the Project on Emerging Nanotechnologies’ recent (Feb.4.10) webcast.From their website (you can click to view the webcast [approx. 54 mins.] from here),

A new review article appearing in Environmental Health Perspectives (EHP) co-authored by Dr. Todd Kuiken, research associate for the Project on Emerging Nanotechnologies (PEN), Dr. Barbara Karn, Office of Research and Development, U.S. Environmental Protection Agency and Marti Otto, Office of Superfund Remediation and Technology Innovation, U.S. Environmental Protection Agency focuses on the use of nanomaterials for environmental cleanup. It provides an overview of current practices; research findings; societal issues; potential environment, health, and safety implications; and possible future directions for nanoremediation. The authors conclude that the technology could be an effective and economically viable alternative for some current site cleanup practices, but potential risks remain poorly understood.

There is an interactive map of remediation sites available here and, if you scroll down to the bottom of the page, you’ll find a link to the review article or you can go here.

I found the information interesting although I was not the intended audience. This was focused primarily on people who are involved in site remediation and/or are from the US. The short story is that more research needs to be done and there have been some very promising results. The use of nanoscale zero-valent iron (nZVI) nanoparticles was the main topic of discussion. It allows for ‘in situ’ site remediation, in other words, you don’t need to move soil and/or pump water through some treatment process. It’s not appropriate for all sites. It can be faster than the current site remediation treatments and it’s cheaper. There was no mention of any problems or hazards using nZVI but there hasn’t been much research either. The technique is now being used in seven different countries (including Canada with one in Ontario and one in Quebec). If I understand it rightly, there is no requirement to report nanotechnology-enabled site remediation so these numbers are based on self-reports. From the article in Environment Health Perspectives,

The number of actual applications of nZVI is increasing rapidly. Only a fraction of the projects has been reported, and new projects show up regularly. Figure 2 and Supplemental Material, Table 2 (doi:10.1289/ehp.0900793.S1) describe 44 sites where nanoremediation methods have been tested for site remediation.

I think that’s it for today, tomorrow some news from NISENet (Nanoscale Informal Science Education Network).

Site remediation and nano materials; perspectives on risk assessment; Leonardo’s call for nano and art; a new nano art/science book

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The Project on Emerging Nanotechnologies (PEN) is holding an event on site remediation on Feb. 4, 2010 (12:30 pm to 1:30 pm EST). From the news release,

A new review article appearing in Environmental Health Perspectives (EHP) co-authored by Dr. Todd Kuiken, Research Associate for the Project on Emerging Nanotechnologies (PEN), Dr. Barbara Karn, Office of Research and Development, U.S. Environmental Protection Agency and Marti Otto, Office of Superfund Remediation and Technology Innovation, U.S. Environmental Protection Agency focuses on the use of nanomaterials for environmental cleanup. It provides an overview of current practices; research findings; societal issues; potential environment, health, and safety implications; and possible future directions for nanoremediation. The authors conclude that the technology could be an effective and economically viable alternative for some current site cleanup practices, but potential risks remain poorly understood.

PEN’s Contaminated Site Remediation: Are Nanomaterials the Answer? features the EHN article’s authors Kulken, Karn, and Otto on a panel with David Rejeski, PEN’s executive director moderating. PEN also has a map detailing almost 60 sites (mostly in the US, 2 in Canada, 4 in Europe, and 1 in Taiwan) where nanomaterials are being used for remediation. More from the news release,

According to Dr. Kuiken, “Despite the potentially high performance and low cost of nanoremediation, more research is needed to understand and prevent any potential adverse environmental impacts, particularly studies on full-scale ecosystem-wide impacts. To date, little research has been done.”

In its 2004 report Nanoscience and nanotechnologies: opportunities and uncertainties, the British Royal Society and Royal Academy of Engineering recommended that the use of free manufactured nanoparticles be prohibited for environmental applications such as remediation until further research on potential risks and benefits had been conducted. The European Commission’s Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) called for further risk research in 2005 while acknowledging environmental remediation technology as one of nanotechnology’s potential benefits.

If you wish to attend in person (i.e. you are in Washington, DC), you are asked to RSVP here (they provide a light lunch starting at 12 pm) or you can watch the webcast (no RSVP necessary and I will put up a link to the webcast closer to the date).

On the topic of risk, Michael Berger has written an in depth piece about a recently published article, Redefining research risk priorities for nanomaterials, in the Journal of Nanoparticle Research. From Berger’s piece,

While research in quantitative risk characterization of nanomaterials is crucially important, and no one advocates abandoning this approach, scientists and policy makers must face the reality that many of these knowledge gaps cannot be expected to be closed for many years to come – and decision making will need to continue under conditions of uncertainty. At the same time, current chemical-based research efforts are mainly directed at establishing toxicological and ecotoxicological and exposure data for nanomaterials, with comparatively little research undertaken on the tools or approaches that may facilitate near-term decisions.

In other words, there’s a big lag between developing new products using nanomaterials and the research needed to determine the health and environmental risks associated both with the production and use of these new materials. The precautionary principle suggests that we not produce or adopt these products until we are certain about risks and how to ameliorate and/or eliminate them. That’s an impossible position as we can never anticipate with any certainty what will happen when something is released to the general public or into the environment at large. From Berger’s piece,

In their article, [Khara Deanna] Grieger [PhD student at Technical University of Denmark (DTU)], Anders Baun, who heads DTU’s Department of Environmental Engineering, and Richard Owens from the Policy Studies Institute in the UK, argue that there has not yet been a significant amount of attention dedicated to the field of timely and informed decision making for near term decisions. “We see this as the central issue for the responsible emergence of nanotechnologies” says Grieger.

Getting back to site remediation using nanomaterials, since it’s already in use as per the map and the authors state that there hasn’t been enough research into risks, do we pull back and adopt the precautionary principle or do we proceed as intelligently as possible in an area where uncertainty rules? That’s a question I will continue to explore as I get my hands on more information.

On a completely different nano front, the Leonardo magazine has issued a call for papers on nano and art,

2011 is the International Year of Chemistry! To celebrate Leonardo is seeking to publish papers and artworks on the intersections of chemistry,
nanotechnology and art for our on-going special section on nanotechnology and the arts. Since its inception nanotech/science has been intimately connected to chemistry; fullerenes, nanoputians, molecular machines, nano-inorganics and self-assembling molecular systems all spring from the minds and labs of chemists, biochemists and chemical engineers. If you’re a nano-oriented chemist who is serious about art, an artist working on the molecular level, or a chemical educator exploring the mysteries of nano through the arts we are especially seeking submissions from you.

You can send proposals, queries, and/or manuscripts to the Leonardo editorial office: leonardomanuscripts@gmail.com. You can read more about the call for papers here at Leblogducorps or you can go here to the Leonardo online journal.

Meanwhile, Andrew Maynard at 2020 Science is posting about a new book which integrates art work in an attempt to explain nanotechnology without ever mentioning it. From Andrew’s posting,

How do you write a book about something few people have heard off, and less seem interested in? The answer, it seems, is to write about something else.

Felice Frankel and George Whitesides have clearly taken this lesson to heart. Judged by the cover alone, their new book “No Small Matter: Science at the Nanoscale” is all about science in the Twilight zone of the nanoscale

– where stuff doesn’t behave in the way intuition says it should.

Drat! I can’t make the indent go away. At any rate, do visit 2020 as Andrew to read more from this posting and at least one other where he has gotten permission to excerpt parts of the book (text and images).

FrogHeart

Commentary about nanotech, science policy and communication, society, and the arts