Tag Archives: remediation

Mopping up that oil spill with a nanocellulose sponge and a segue into Canadian oil and politics

Empa (Swiss Federal Laboratories for Materials Science and Technology or ,in German, Eidgenössische Materialprüfungs- und Forschungsanstalt) has announced the development of a nanocellulose sponge useful for cleaning up oil spills in a May 5, 2014 news item on Nanowerk (Note: A link has been removed),

A new, absorbable material from Empa wood research could be of assistance in future oil spill accidents: a chemically modified nanocellulose sponge. The light material absorbs the oil spill, remains floating on the surface and can then be recovered. The absorbent can be produced in an environmentally-friendly manner from recycled paper, wood or agricultural by-products (“Ultralightweight and Flexible Silylated Nanocellulose Sponges for the Selective Removal of Oil from Water”).

A May 2, 2014 Empa news release (also on EurekAlert*}, which originated the news item, includes a description of the potential for oil spills due to transport issues, Empa’s proposed clean-up technology, and a request for investment,

All industrial nations need large volumes of oil which is normally delivered by ocean-going tankers or via inland waterways to its destination. The most environmentally-friendly way of cleaning up nature after an oil spill accident is to absorb and recover the floating film of oil. The Empa researchers Tanja Zimmermann and Philippe Tingaut, in collaboration with Gilles Sèbe from the University of Bordeaux, have now succeeded in developing a highly absorbent material which separates the oil film from the water and can then be easily recovered, “silylated” nanocellulose sponge. In laboratory tests the sponges absorbed up to 50 times their own weight of mineral oil or engine oil. They kept their shape to such an extent that they could be removed with pincers from the water. The next step is to fine tune the sponges so that they can be used not only on a laboratory scale but also in real disasters. To this end, a partner from industry is currently seeked.

Here’s what the nanocellulose sponge looks like (oil was dyed red and the sponge has absorbed it from the water),

The sponge remains afloat and can be pulled out easily. The oil phase is selectively removed from the surface of water. Image: Empa

The sponge remains afloat and can be pulled out easily. The oil phase is selectively removed from the surface of water.
Image: Empa

The news release describes the substance, nanofibrillated cellulose (NFC), and its advantages,

Nanofibrillated Cellulose (NFC), the basic material for the sponges, is extracted from cellulose-containing materials like wood pulp, agricultural by products (such as straw) or waste materials (such as recycled paper) by adding water to them and pressing the aqueous pulp through several narrow nozzles at high pressure. This produces a suspension with gel-like properties containing long and interconnected cellulose nanofibres .

When the water from the gel is replaced with air by freeze-drying, a nanocellulose sponge is formed which absorbs both water and oil. This pristine material sinks in water and is thus not useful for the envisaged purpose. The Empa researchers have succeeded in modifying the chemical properties of the nanocellulose in just one process step by admixing a reactive alkoxysilane molecule in the gel before freeze-drying. The nanocellulose sponge loses its hydrophilic properties, is no longer suffused with water and only binds with oily substances.

In the laboratory the “silylated” nanocellulose sponge absorbed test substances like engine oil, silicone oil, ethanol, acetone or chloroform within seconds. Nanofibrillated cellulose sponge, therefore, reconciles several desirable properties: it is absorbent, floats reliably on water even when fully saturated and is biodegradable.

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

Ultralightweight and Flexible Silylated Nanocellulose Sponges for the Selective Removal of Oil from Water by Zheng Zhang, Gilles Sèbe, Daniel Rentsch, Tanja Zimmermann, and Philippe Tingaut. Chem. Mater., 2014, 26 (8), pp 2659–2668 DOI: 10.1021/cm5004164 Publication Date (Web): April 10, 2014

Copyright © 2014 American Chemical Society

This article is behind a paywall.

I featured ‘nanocellulose and oil spills’ research at the University Wisconsin-Madison in a Feb. 26, 2014 post titled, Cleaning up oil* spills with cellulose nanofibril aerogels (Note: I corrected a typo in my headline hence the asterisk). I also have a Dec. 31, 2013 piece about a nanotechnology-enabled oil spill recovery technology project (Naimor) searching for funds via crowdfunding. Some major oil projects being considered in Canada and the lack of research on remediation are also mentioned in the post.

Segue Alert! As for the latest on Canada and its oil export situation, there’s a rather interesting May 2, 2014 Bloomberg.com article Canada Finds China Option No Easy Answer to Keystone Snub‘ by Edward Greenspon, Andrew Mayeda, Jeremy van Loon and Rebecca Penty describing two Canadian oil projects and offering a US perspective,

It was February 2012, three months since President Barack Obama had phoned the Canadian prime minister to say the Keystone XL pipeline designed to carry vast volumes of Canadian crude to American markets would be delayed.

Now Harper [Canadian Prime Minister Stephen Harper] found himself thousands of miles from Canada on the banks of the Pearl River promoting Plan B: a pipeline from Alberta’s landlocked oil sands to the Pacific Coast where it could be shipped in tankers to a place that would certainly have it — China. It was a country to which he had never warmed yet that served his current purposes. [China's President at that time was Hu Jintao, 2002 - 2012; currently the President is Xi Jinping, 2013 - ]

The writers do a good job of describing a number of factors having an impact on one or both of the pipeline projects. However, no mention is made in the article that Harper is from the province of Alberta and represents that province’s Calgary Southwest riding. For those unfamiliar with Calgary, it is a city dominated by oil companies. I imagine Mr. Harper is under considerable pressure to resolve oil export and transport issues and I would expect they would prefer to resolve the US issues since many of those oil companies in Calgary have US headquarters.

Still, it seems simple, if the US is not interested as per the problems with the Keystone XL pipeline project, ship the oil to China via a pipeline through the province of British Columbia and onto a tanker. What the writers do not mention is yet another complicating factor, Trudeau, both Justin and, the deceased, Pierre.

As Prime Minister of Canada, Pierre Trudeau was unloved in Alberta, Harper’s home province, due to his energy policies and the formation of the National Energy Board. Harper appears, despite his denials, to have an antipathy towards Pierre Trudeau that goes beyond the political to the personal and it seems to extend beyond Pierre’s grave to his son, Justin. A March 21, 2014 article by Mark Kennedy for the National Post describes Harper’s response to Trudeau’s 2000 funeral this way,

Stephen Harper, then the 41-year-old president of the National Citizens Coalition (NCC), was a proud conservative who had spent three years as a Reform MP. He had entered politics in the mid-1980s, in part because of his disdain for how Pierre Trudeau’s “Just Society” had changed Canada.

So while others were celebrating Trudeau’s legacy, Harper hammered out a newspaper article eviscerating the former prime minister on everything from policy to personality.

Harper blasted Trudeau Sr. for creating “huge deficits, a mammoth national debt, high taxes, bloated bureaucracy, rising unemployment, record inflation, curtailed trade and declining competitiveness.”

On national unity, he wrote that Trudeau was a failure. “Only a bastardized version of his unity vision remains and his other policies have been rejected and repealed by even his own Liberal party.”

Trudeau had merely “embraced the fashionable causes of his time,” wrote Harper.

Getting personal, he took a jab at Trudeau over not joining the military during the Second World War: “He was also a member of the ‘greatest generation,’ the one that defeated the Nazis in war and resolutely stood down the Soviets in the decades that followed. In those battles however, the ones that truly defined his century, Mr. Trudeau took a pass.”

The article was published in the National Post Oct. 5, 2000 — two days after the funeral.

Kennedy’s article was occasioned by the campaign being led by Harper’;s Conservative party against the  leader (as of April 2013) of the Liberal Party, Justin Trudeau.

It’s hard to believe that Harper’s hesitation over China is solely due to human rights issues especially  since Harper has not been noted for consistent interest in those issues and, more particularly, since Prime Minister Pierre Trudeau was one of the first ‘Western’ leaders to visit communist China . Interestingly, Harper has been much more enthusiastic about the US than Pierre Trudeau who while addressing the Press Club in Washington, DC in March 1969, made this observation (from the Pierre Trudeau Wikiquote entry),

Living next to you [the US] is in some ways like sleeping with an elephant. No matter how friendly and even-tempered is the beast, if I can call it that, one is affected by every twitch and grunt.

On that note, I think Canada is always going to be sleeping with an elephant; the only question is, who’s the elephant now? In any event, perhaps Harper is more comfortable with the elephant he knows and that may explain why China’s offer to negotiate a free trade agreement has been left unanswered (this too was not noted in the Bloomberg article). The offer and lack of response were mentioned by Yuen Pau Woo, President and CEO of the Asia Pacific Foundation of Canada, who spoke at length about China, Canada, and their trade relations at a Jan. 31, 2014 MP breakfast (scroll down for video highlights of the Jan. 31, 2014 breakfast) held by Member of Parliament (MP) for Vancouver-Quadra, Joyce Murray.

Geopolitical tensions and Canadian sensitivities aside, I think Canadians in British Columbia (BC), at least, had best prepare for more oil being transported and the likelihood of spills. In fact, there are already more shipments according to a May 6, 2014 article by Larry Pynn for the Vancouver Sun,

B.C. municipalities work to prevent a disastrous accident as rail transport of oil skyrockets

The number of rail cars transporting crude oil and petroleum products through B.C. jumped almost 200 per cent last year, reinforcing the resolve of municipalities to prevent a disastrous accident similar to the derailment in Lac-Mégantic in Quebec last July [2013].

Transport Canada figures provided at The Vancouver Sun’s request show just under 3,400 oil and petroleum rail-car shipments in B.C. last year, compared with about 1,200 in 2012 and 50 in 2011.

The figures come a week after The Sun revealed that train derailments jumped 20 per cent to 110 incidents last year in B.C., the highest level in five years.

Between 2011 and 2012, there was an increase of 2400% (from 50 to 1200) of oil and petroleum rail-car shipments in BC. The almost 300% increase in shipments between 2012 and 2013 seems paltry in comparison.  Given the increase in shipments and the rise in the percentage of derailments, one assumes there’s an oil spill waiting to happen. Especially so, if the Canadian government manages to come to an agreement regarding the proposed pipeline for BC and frankly, I have concerns about the other pipeline too, since either will require more rail cars, trucks, and/or tankers for transport to major centres edging us all closer to a major oil spill.

All of this brings me back to Empa, its oil-absorbing nanocellulose sponges, and the researchers’ plea for investors and funds to further their research. I hope they and all the other researchers (e.g., Naimor) searching for ways to develop and bring their clean-up ideas to market find some support.

*EurekAlert link added May 7, 2014.

ETA May 8, 2014:  Some types of crude oil are more flammable than others according to a May 7, 2014 article by Lindsay Abrams for Salon.com (Note: Links have been removed),

Why oil-by-rail is an explosive disaster waiting to happen
A recent spate of fiery train accidents all have one thing in common: highly volatile cargo from North Dakota

In case the near continuous reports of fiery, deadly oil train accidents hasn’t been enough to convince you, Earth Island Journal is out with a startling investigative piece on North Dakota’s oil boom and the dire need for regulations governing that oil’s transport by rail.

The article is pegged to the train that derailed and exploded last summer in  [Lac-Mégantic] Quebec, killing 47 people, although it just as well could have been the story of the train that derailed and exploded in Alabama last November, the train that derailed and exploded in North Dakota last December, the train that derailed and exploded in Virginia last week or — let’s face it — any future accidents that many see as an inevitability.

The Bakken oil fields in North Dakota are producing over a million barrels of crude oil a day, more than 60 percent of which is shipped by rail. All that greenhouse gas-emitting fossil fuel is bad enough; that more oil spilled in rail accidents last year than the past 35 years combined is also no small thing. But the particular chemical composition of Bakken oil lends an extra weight to these concerns: according to the Pipeline and Hazardous Materials Safety Administration, it may be more flammable and explosive than traditional crude.

While Abrams’ piece is not focused on oil cleanups, it does raise some interesting questions about crude oil transport and whether or not the oil from Alberta might also be more than usually dangerous.

Cleaning up water polluted by agricultural fertilizers

Researchers at Rice University (Texas, US) have announced a new catalyst for cleaning nitrites from water polluted by agricultural fertilizers (from the Rice University November 25, 2013 news release ,[also on EurekAlert]),

Chemical engineers at Rice University have found a new catalyst that can rapidly break down nitrites, a common and harmful contaminant in drinking water that often results from overuse of agricultural fertilizers.

Nitrites and their more abundant cousins, nitrates, are inorganic compounds that are often found in both groundwater and surface water. The compounds are a health hazard, and the Environmental Protection Agency places strict limits on the amount of nitrates and nitrites in drinking water. While it’s possible to remove nitrates and nitrites from water with filters and resins, the process can be prohibitively expensive.

There is a map illustrating the problem,

CAPTION: Many areas of the United States are at risk of contamination of drinking water by nitrates and nitrites due to overuse of agricultural fertilizers. CREDIT: USGS

CAPTION: Many areas of the United States are at risk of contamination of drinking water by nitrates and nitrites due to overuse of agricultural fertilizers.
CREDIT: USGS Courtesy: Rice University

Here’s more about these new catalysts designed to ‘scrub’ water clean (from the news release; Note: Links have been removed),

.. Michael Wong, professor of chemical and biomolecular engineering at Rice and the lead researcher on the new study [says] “Our group has studied engineered gold and palladium nanocatalysts for several years. We’ve tested these against chlorinated solvents for almost a decade and in looking for other potential uses for these we stumbled onto some studies about palladium catalysts being used to treat nitrates and nitrites; so we decided to do a comparison.”

Catalysts are the matchmakers of the molecular world: They cause other compounds to react with one another, often by bringing them into close proximity, but the catalysts are not consumed by the reaction.

In a new paper in the journal Nanoscale, Wong’s team showed that engineered nanoparticles of gold and palladium were several times more efficient at breaking down nitrites than any previously studied catalysts. The particles, which were invented at Wong’s Catalysis and Nanomaterials Laboratory, consist of a solid gold core that’s partially covered with palladium.

Over the past decade, Wong’s team has found these gold-palladium composites have faster reaction times for breaking down chlorinated pollutants than do any other known catalysts. He said the same proved true for nitrites, for reasons that are still unknown.

“There’s no chlorine in these compounds, so the chemistry is completely different,” Wong said. “It’s not yet clear how the gold and palladium work together to boost the reaction time in nitrites and why reaction efficiency spiked when the nanoparticles had about 80 percent palladium coverage. We have several hypotheses we are testing out now. ”

He said that gold-palladium nanocatalysts with the optimal formulation were about 15 times more efficient at breaking down nitrites than were pure palladium nanocatalysts, and about 7 1/2 times more efficient than catalysts made of palladium and aluminum oxide.

I gather this team will be doing more work before promoting the use of gold-palladium nanocatalysts (from the news release),

Wong said he can envision using the gold-palladium catalysts in a small filtration unit that could be attached to a water tap, but only if the team finds a similarly efficient catalyst for breaking down nitrates, which are even more abundant pollutants than nitrites.

“Nitrites form wherever you have nitrates, which are really the root of the problem,” Wong said. “We’re actively studying a number of candidates for degrading nitrates now, and we have some positive leads.”

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

Supporting palladium metal on gold nanoparticles improves its catalysis for nitrite reduction by Huifeng Qian, Zhun Zhao, Juan C. Velazquez, Lori A. Pretzer, Kimberly N. Hecka and Michael S. Wong. Nanoscale, 2014, Advance Article DOI: 10.1039/C3NR04540D First published online 30 Oct 2013

This paper is behind a paywall.

Graphene and radioactive waste

In fact, the material in question is graphene oxide and researchers at Rice University (Texas) and Lomonosov Moscow State University have found that it can rapidly remove radioactive material from water  From the Jan. 8, 2013 news item on ScienceDaily,

A collaborative effort by the Rice lab of chemist James Tour and the Moscow lab of chemist Stepan Kalmykov determined that microscopic, atom-thick flakes of graphene oxide bind quickly to natural and human-made radionuclides and condense them into solids. The flakes are soluble in liquids and easily produced in bulk.

The Rice University Jan. 8, 2013 news release, which originated the news item, was written by Mike Williams and provides additional insight and quotes from the researchers (Note: Links have been removed),

The discovery, Tour said, could be a boon in the cleanup of contaminated sites like the Fukushima nuclear plants damaged by the 2011 earthquake and tsunami. It could also cut the cost of hydraulic fracturing (“fracking”) for oil and gas recovery and help reboot American mining of rare earth metals, he said.

Graphene oxide’s large surface area defines its capacity to adsorb toxins, Kalmykov said. “So the high retention properties are not surprising to us,” he said. “What is astonishing is the very fast kinetics of sorption, which is key.”

“In the probabilistic world of chemical reactions where scarce stuff (low concentrations) infrequently bumps into something with which it can react, there is a greater likelihood that the ‘magic’ will happen with graphene oxide than with a big old hunk of bentonite,” said Steven Winston, a former vice president of Lockheed Martin and Parsons Engineering and an expert in nuclear power and remediation who is working with the researchers. “In short, fast is good.”

Here’s how it works (from the news release; Note: Links have been removed),

The researchers focused on removing radioactive isotopes of the actinides  and lanthanides  – the 30 rare earth elements in the periodic table – from liquids, rather than solids or gases. “Though they don’t really like water all that much, they can and do hide out there,” Winston said. “From a human health and environment point of view, that’s where they’re least welcome.”

Naturally occurring radionuclides are also unwelcome in fracking fluids that bring them to the surface in drilling operations, Tour said. “When groundwater comes out of a well and it’s radioactive above a certain level, they can’t put it back into the ground,” he said. “It’s too hot. Companies have to ship contaminated water to repository sites around the country at very large expense.” The ability to quickly filter out contaminants on-site would save a great deal of money, he said.

He sees even greater potential benefits for the mining industry. Environmental requirements have “essentially shut down U.S. mining of rare earth metals, which are needed for cell phones,” Tour said. “China owns the market because they’re not subject to the same environmental standards. So if this technology offers the chance to revive mining here, it could be huge.”

Tour said that capturing radionuclides does not make them less radioactive, just easier to handle. “Where you have huge pools of radioactive material, like at Fukushima, you add graphene oxide and get back a solid material from what were just ions in a solution,” he said. “Then you can skim it off and burn it. Graphene oxide burns very rapidly and leaves a cake of radioactive material you can then reuse.”

The low cost and biodegradable qualities of graphene oxide should make it appropriate for use in permeable reactive barriers, a fairly new technology for in situ groundwater remediation, he said.

Romanchuk, Slesarev, Kalmykov and Tour are co-authors of the paper with Dmitry Kosynkin, a former postdoctoral researcher at Rice, now with Saudi Aramco. Kalmykov is radiochemistry division head and a professor at Lomonosov Moscow State University. Tour is the T.T. and W.F. Chao Chair in Chemistry as well as a professor of mechanical engineering and materials science and of computer science at Rice.

Here’s a ‘before’ shot of solution with graphene oxide and an ‘after’ shot where radionuclides have been added and begun to clump,

A new method for removing radioactive material from solutions is the result of collaboration between Rice University and Lomonosov Moscow State University. The vial at left holds microscopic particles of graphene oxide in a solution. At right, graphene oxide is added to simulated nuclear waste, which quickly clumps for easy removal. Image by Anna Yu. Romanchuk/Lomonosov Moscow State University

A new method for removing radioactive material from solutions is the result of collaboration between Rice University and Lomonosov Moscow State University. The vial at left holds microscopic particles of graphene oxide in a solution. At right, graphene oxide is added to simulated nuclear waste, which quickly clumps for easy removal. Image by Anna Yu. Romanchuk/Lomonosov Moscow State University

As noted in the ScienceDaily news item, the research has been published in the Royal Society’s Physical Chemistry Chemical Physics journal,

Anna Yu. Romanchuk, Alexander Slesarev, Stepan N. Kalmykov, Dmitry Kosynkin, James M Tour. Graphene Oxide for Effective Radionuclide Removal. Physical Chemistry Chemical Physics, 2012; DOI: 10.1039/C2CP44593J

This article is behind a paywall.